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Which kind of vitamin C is best for skin? Episode 31

What’s the best kind of vitamin C for skin? Plus: Randy and I talk about the experimental MINK makeup printer.

Show notes

Beauty Science News

3D printing comes to cosmetics! This week we discuss the pros and cons of the new MINK makeup printer.

Question of the week: What kind of vitamin C works best on skin?

Illdiko (from Hungary) asks..I really love vitamin C serums, but I would like to use them properly. Do vitamin C products really need a special low pH? And what about their derivates, like Magnesium Ascorbyl Phosphate and others? Which vitamin C ingredient is the best?”

What’s the deal with Vitamin C?

Vitamin C is a chemical called ascorbic acid that is naturally occurring in skin. It is known to play a role in collagen production. In addition, when topically applied it is thought to help heal acne, increase the barrier function of skin to decrease moisture loss, protect from UV radiation, and prevent age spots.

Sounds too good to be true, huh? Well there is a downside – it’s difficult to deliver VC to skin in a form that is stable, effective and non-irritating.

There are something like 7 or 8 different forms of VC that are used in cosmetics and there’s a LOT of noise out there about how the different versions work, how much to use, what kind of formula is required to deliver the ingredient, and so forth.

So, today, we’re going to try to get to the bottom of that mess by reviewing the best scientific data available on each ingredient. And we’ll do that using the three Kligman questions format that we’ve used before. Randy, want to describe that again for our readers?

How to prove an anti-aging ingredient works – the Kligman questions

1. Based on the chemistry of the ingredient, is there any scientific mechanism that could explain why it would work?
2. Does it penetrate to the part of the skin where it needs to be in order to work?
3. Are there peer reviewed, double blind, placebo controlled studies demonstrating the ingredient really works when applied to real people?

Our assessment is based primarily on a paper which reviews the technical literature on Vitamin C through 2012: “Stability, transdermal penetration and cutaneous effects of ascorbic acid and its derivatives” from the Journal of Cosmetic Dermatology, 2012.

Let’s start by discussion the mechanism. Remember the active form is ascorbic acid so all the derivatives must be converted to ascorbic acid on the skin.

Is there a mechanism that explains how Vitamin C works?

Remember that unlike many other anti aging ingredients, Vitamin C is naturally found in skin (mostly in the epidermis, some in the dermis) and it’s role in skin biology is well documented. For example…

Protecting from UV damage
Although VC is NOT a sunscreen but it protects skin from the free radicals that are caused by UV exposure. It’s been shown to reduce lipid peroxidation, limit the release of pro-inflammatory cytokines, protect against apoptosis (or cell death) and to reduce redox-sensitive cell signaling. All this means that VC reduces many of the nasty effects of sun exposure.

Increasing collagen to reduce wrinkles
As you know collagen collapse is a major cause of wrinkles. Vitamin C regulates the synthesis of collagen and it does this by hydroxylating collagen which makes it more stable and improves the way it supports the epidermis.

Reducing skin pigmentation
VC not only reduces melanin production but it also reduces oxidation of the melanin that is produced. It’s also thought to reverse the conversion of DOPA to o-DOPA quinone (which is a skin pigment).

So, as you can see, the effects of VC in the skin are well understood. Now let’s look at the other properties of each ingredient and what kind of data is available to prove that they work.

Ascorbic Acid (AA)

Is it Stable? Stable at pH less than 3.5 in aqueous solution and it’s stable in anhydrous systems

Does it penetrate? Ex vivo testing proves it penetrates as a solution or micro particles

Does it convert to Ascorbic Acid? No conversion required.

Protects from UV damage: Yes, human in vivo testing.

Increases collagen synthesis: Yes, human in vivo testing.

Reduces skin pigmentation: Yes, human in vivo testing.

So this ingredient is the gold standard for Vitamin C. However because it’s often used at very low pH it can be harsh to skin which has lead to the development of other versions of AA. For example….

Sodium Ascorbyl Phosphate (SAP)

Is it Stable? Stable at pH 7

Does it penetrate? There is limited ex vivo animal testing which shows it penetrates.

Does it convert to Ascorbic Acid? There is no data showing it converts to AA.

Protects from UV damage: Yes, human in vivo testing shows is protects but less effective than AA.

Increases collagen synthesis: Yes, in vitro testing only and it’s less effective than MAP.

Reduces skin pigmentation: Yes, human in vivo testing (but from trade journal only so the data may be less robust.)

Magnesium Ascorbyl Phosphate (MAP)

Is it Stable?  Stable at pH 7

Does it penetrate? Yes it penetrates, but data is limited to ex vivo animal testing.

Does it convert to Ascorbic Acid? In vitro testing indicates it converts to AA.

Protects from UV damage: No data.

Increases collagen synthesis: Yes but only in vitro testing. Apparently equally as effective as AA.

Reduces skin pigmentation: Yes, human in vivo testing.

Ascorbyl Palmitate (AA-PAL)

Is it Stable? Same stability issues as AA (requires low pH or anhydrous system.)

Does it penetrate? In vivo animal testing shows it penetrates but it’s very dependent upon the formula.

Does it converts to Ascorbic Acid?  No data showing that it converts.

Protects from UV damage: Yes, animal in vivo testing shows it protects from UV.

Increases collagen synthesis: Yes, but in vitro testing only.

Reduces skin pigmentation: No data showing that it works.

Ascorbyl Tetra-Isopalmitate (VC-IP)

Is it Stable? It’s stable at pH less than 5.

Does it penetrate? According to a trade publication, human ex vivo testing shows it penetrates better than MAP.

Does it converts to Ascorbic Acid? In vitro testing shows it converts to AA.

Protects from UV damage: Yes but in vitro data only.

Increases collagen synthesis: Yes but in vitro data only.

Reduces skin pigmentation: Yes, human in vivo testing (according to trade journal.)

Ascorbyl Glucoside (AA-2G)

Is it Stable? Yes, stable at a range of pH.

Does it penetrate? In vitro testing shows it penetrates.

Does it converts to Ascorbic Acid? In vitro testing shows it converts to AA.

Protects from UV damage: Yes, human in vivo testing shows it protects but it’s less effective than SAP.

Increases collagen synthesis: Yes but in vitro data only.

Reduces skin pigmentation: In vitro testing shows it diminishes dark spots. 

Ascorbyl 2-Phosphate 6-Palmitate (APPS)

Is it Stable? Stable at pH 7

Does it penetrate? In vivo animal data shows it penetrates.

Does it converts to Ascorbic Acid? In vitro data shows it converts to AA.

Protects from UV damage: No data.

Increases collagen synthesis: No data.

Reduces skin pigmentation: Yes, human in vivo data shows it diminishes dark spots.

3-O-Ethyl Ascorbate (EAC)

Is it Stable? No published data on stability.

Does it penetrate? Ex vivo animal testing shows it penetrates better than AA-2G.

Does it converts to Ascorbic Acid? No published data showing it converts to AA.

Protects from UV damage: No data.

Increases collagen synthesis: No data.  

Reduces skin pigmentation: Human in vivo data shows it works against dark spots.

Tip #1 for finding the best product: Ask for Ascorbic Acid

This much is clear: of all the Vitamin C derivatives, Ascorbic Acid has the best data to prove that it really works for all three main functions. So, if possible, why wouldn’t you use AA?

That doesn’t mean that ANY product with AA on the label will be best. There are other factors at play…Which brings us to tip #2…

Tip #2 for finding the best product: Concentrate on the concentration

So how much AA should a product contain?

According to the Pauling Inst. the maximum skin absorption occurs at 20%. Higher concentrations actually have less absorption. Which is good since high concentrations are also more irritating.

Should you go lower? Paula Begon says that a proven range for vitamin C effectiveness is generally between 0.3% and 10%. 0.3 is a LONG way from the maximum absorption of 20% so that seems low.

If you can stand the irritation, 10% or even 15% should give better absorption.

Tip #3 for finding the best product: Watch out for water

AA can begin to oxide (which causes it to be used up) as soon as it’s dissolved in water. Look for products where water is NOT one of the first ingredients. That gives you a better chance of finding a product that will really work. That means looks for serums instead of cream based products.

Also, if water is present, look for products that use stabilizing agents – Paula’s Choice is good for this.

Tip #4 for finding the best product: Look for low pH

As we noted, AA is unstable above 3.5 or so. Look for low pH products. Of course pH is only meaningful if water is present so it’s less of an issue in the kinds of water free formulas we just discussed.

Tip #5 for finding the best product: Purchase proper packaging

Any Vitamin C ingredient must be properly packaged to protect it from excess light and air.

Look for pump packaging (or individually sealed single use capsules) to protect from air. I would even avoid products in plastic tubes unless you know they’re used some kind of laminate to act as a barrier to oxygen transmission.

Avoid clear packages to protect from light. If it’s a glass jar make it dark.

Bonus tips:

Watch out for irritation

As we said, AA can cause redness and stinging. Be prepared to switch to another type if irritation is to great. The alternative may be less effective but you’ll be likely to use it more often if it’s gentle to your skin.

Don’t rush it!

After applying a VC product you should wait a while before applying any other products.

That’s because other ingredients can trigger oxidation and if they’re applied on top of the AA before it can be absorbed into your skin it could become inactive.

The Beauty Brains bottom line

So based on the data we’ve seen, ascorbic acid is the best version of  Vitamin C to use in an anti-aging product.

But, just having ascorbic acid on the ingredient list doesn’t make a product “the best.” A well formulated product based on other derivatives could be better than a poorly formulated product based on ascorbic acid.

You need to keep in mind that the efficacy of any vitamin C based product depends on not only the type of Vitamin C, but also the concentration, the other ingredients in the formula and the packaging.

But following our 5 tips should help you pick a product that’s more likely to work at a price you can afford.

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Comments on this entry are closed.

  • farawayspices May 20, 2014, 8:25 am

    Thanks for an informative article. I understand that the formulation is important when it comes to delivery and stability in the bottle. However, I’ve heard there is some concern that once applied, vitamin c can oxidize on the skin when it is exposed to sunlight, possibly leading to skin damage. Is this true?

    • Randy Schueller May 22, 2014, 6:24 am

      Since vitamin C is naturally occurring in skin this seems unlikely but if you have a reference to where you read this I can check it out.

      • Cheryl Brown March 19, 2015, 1:59 pm


        he following five types of vitamin C are commonly used in cosmetic formulations today. Make a note of their chemical names and check for them on your product’s ingredient list. If you’re not sure about what your ingredient list means,email FeleciaRose or leave a comment and I’ll advise you ASAP.

        1. L-ascorbic Acid aka Ascorbic Acid (AA)
        AA is the water soluble, biologically active form of vitamin C found in nature. This is the form the body uses to build skin, repair wounds, and protect itself from disease and disorder. Be careful of any vitamin C serum that turns from clear to yellow, tan or brown. It contains AA that’s being oxidized by air and light. Some manufacturers color their solutions orange to hide what’s going on.
        2. Magnesium Ascorbyl Phosphate (MAP)
        Magnesium-L-ascorby-Phosphate (VC-PMG)
        Ascorbic Acid Phosphate (AA2P)
        These are different names for essentially the same derivative of AA formed by adding magnesium phosphate in a process known as esterification. The addition of the phosphate raises the pH level ascorbic acid remains stable in when in solution.Sodium ascorbyl phosphate is another vitamin C derivative synthesized to deliver the same benefit.Ascorbic acid naturally occurs at a pH of around 3.5 which is fairly acidic. Its acidity creates problems in emulsions. Emulsions are carriers like lotions and creams formulated to make products look and feel nice. The addition of a phosphate group to ascorbic acid, whether magnesium or sodium, raises the pH level it can survive in to greater than 7.
        3. Ascorbyl Palmitate aka Ascorbic Acid-6-Palmitate (AA6P)
        This is another ester of AA using palmitate (palmitic acid) to form an oil-soluble molecule. The idea behind creating an oil-soluble derivative is to enhance penetration through the stratum corneum (SC). The SC contains a large number of lipids (fats) by Nature’s design to help keep out pathogens. Lipid soluble (oil soluble) derivatives are proven to penetrate more readily, however there are major problems with making an AA derivate oil soluble. See our post “Why it can be Disastrous to use the Wrong Vitamin C” for details. In the meantime, if you use a product containing ascorbyl palmitate, be sure to stay out of the sun. Under UV exposure, ascorbyl palmitate is toxic to skin cells and contributes to disease states including skin cancer.
        4. Ascorbyl Tretaisopalmitate (ATIP)
        Tetrahexyldecyl Ascorbate
        Ascorbyl tretaisopalmitate and tetrahexyldecyl ascorbate are two names for the same molecule. The first (ATIP) is the chemical name while the second (tetrahexyldecyl ascorbate) is the marketing name. It is likely the marketing name was chosen to disassociate it from “palmitate” which as discussed above, is toxic to skin cells under sun exposure.
        5. Liposome Vitamin C
        Encasing a molecule in a liposome is a technique devised by cosmetic chemists to impart stability and penetration properties to AA and other molecules. The molecule is wrapped in a bubble of lipids (the liposome) making it oil soluble which is a really bad idea when it comes to vitamins. Worse, chemists use ascorbyl palmitate when making liposome vitamin C. The addition of more lipids (the liposome) may only worsen the ingredient’s toxicity. Please see our post “Why it can be Disastrous to use the Wrong Vitamin C” for details.
        The safest form of vitamin C
        For the naturalists amongst us, it will come as no surprise that the safest form of vitamin C is ascorbic acid

  • Antoinette May 20, 2014, 9:46 am

    I’ve been seeing homemade formulations vitamin C serums for years now. Can they be an effective alternate to expensive (and sometimes ineffective) store bands? This one is a really popular recipe.


    • Randy Schueller May 22, 2014, 6:23 am

      I checked out the recipe and it looks pretty reasonable. There are just a couple of watch outs:

      1. The formula appears to be about 30% ascorbic acid. We know that at concentrations above 20% skin absorption is reduced so this is somewhat of an issue.

      2. She says to use distilled water but that’s not pure enough because it may contain trace organics which could destabilize the mixture. You should use deionized water which is more pure.

      3. When mixing vitamin C products at home you need to make sure you’re not using any utensils that could contribute anything that could destabilize the mixture. For example use glass bowls instead of metal.

      • sal August 13, 2015, 4:02 pm

        This is why you people should not be doing this stuff at all especially not at home.

        None of you have a chemistry degree(yes I do). Water is more of an oxidant than air is to vitamin C. So no matter how “clean” your water is it will still oxidize!

        • Bio October 30, 2015, 10:33 am

          for the guy who has a chem degree. can u pls explain why water has a greater oxidizing power than air and what do you think phrama use to dissolve it: ethanol? the solubility of vita C in water is 33g/100ml and that is slightly higher than the most concentrated vit C available out there (20 -25%). also do not assume people’s credentials. what degree do u have in chem? I worked with people who had a PHD in chem , they were not expert in all chem matters. I hold a PhD as well but in Bio.

          • Randy Schueller October 30, 2015, 12:49 pm

            Can u pls explain why water has a greater oxidizing power than air?
            We don’t really do basic chemistry tutorials but you should be able to find out by searching for “oxidation/reduction potential” or something similar.

            What do you think phrama use to dissolve it: ethanol?
            It depends on which product your talking about. You can check the ingredient list to see if it contains ethanol.

            What degree do u have in chem?
            I have a BS in Chem, Perry has a Masters in BioChem.

      • Raghad Salim February 9, 2018, 6:44 am

        The percentage 20% of vit c mean 20 gm or mg wt in 100 ml??

  • Christina May 21, 2014, 10:55 pm

    Thank you for the breakdown of the difference between the different Vitamin C options!

    I have the misfortune of breaking out from all forms of Vitamin C.I am a huge advocate for it however.

    I noticed that Ester C didn’t make it on the lineup for review.

    Ascorbic Acid is the most effective water-soluble form of Vitamin C but what are your thoughts on Ester C as an effective fat-soluble form of Vitamin C?

    • Randy Schueller May 22, 2014, 6:04 am

      Ester-C is the calcium salt of ascorbic acid and it’s typically sold as a dietary supplement, taken orally. I’ve never seen any data related to using it topically. Of course there’s also Ester-X which travels back from the future to fight free radicals. But we’ll have to wait until this weekend to find out if that really works or not.

      • Christina May 22, 2014, 9:29 am

        Skincare companies are just starting to market that they have Ester C in them stating that it’s a higher Ph (Ph 7) and that since it is fat-soluble it is more effective and stable on skin.

        Dr. Perricone started it a few years ago with his product “Vitamin C Ester 15”..here are it’s claims.

        What is it: Vitamin C Ester 15 represents one of Dr. Perricone’s most advanced revolutionary technologies. Patented for topical application, Vitamin C Ester 15 is formulated with the highest concentration of Vitamin C Ester available in any Dr. Perricone product, at 15%–making it a powerful treatment to help fight free radical attack.

        Why is it different: Vitamin C Ester is composed of natural vitamin C fused with a fatty acid derived from palm oil. This combination creates a fat-soluble chemical bond that works on three levels. One, it works on the skin structure to maintain firmness and tone; two, it dramatically improves texture; three, it restores the radiance and glow of youthful skin in only seven days.

        Now, for the record..I have a love/hate relationship with anything related to Dr. Perricone so I automatically eye roll at his blow hard write-ups then wonder if I should reach for my wallet.

        Other brands jumping on the Ester C train are JASON Skincare, Serious Skincare and Kiss My Face.

        Since this is a newer trend I am still trying to gather data before I recommend it to clients.

        I personally think the Ester-X sounds like an amazing ingredient and prefer Professor X to Perricone any day!

        • Tammie September 14, 2016, 6:32 am

          Actually, Shea Terra Organics was the very first company to use Ester-C in their products.

      • melissa December 26, 2014, 7:55 pm

        In skin care vitamin c ester was also used in the form of ascorbly palmitate, and now the very popular ascorbly tetraisopalmitate or tetraheclydecly ascorbic.

        See my question below.

        • Eli June 27, 2017, 7:14 pm

          Dr. Perricone actually uses the Tetrahexyldecyl Ascorbate variant of Vitamin C. One thing I find alarming is that you mentioned the site states a percentage of 15? Tetra (unlike L-Ascorbic Acid) is used in lesser concentrations. So an effective concentration would be a 3% as opposed to an L-Ascorbic of 15%, for example. I’ve only seen percentages go up to about 7% for Tetra, which Perricone calls an Ester.

          I use a Tetra vitamin C serum from Medik8 (made in the UK). It’s based in Jojoba Oil as opposed to water, since it’s oil soluble; therefore, able (so they say) to penetrate the skin. I’ve found that it can help with brightening the skin and improving the texture. However, vitamin C serums alone won’t do anything for wrinkles or folds. I think some people’s darker shadows may lighten overtime, giving the illusion wrinkles are subsiding.

          I hope that helps.

          • LIZ February 20, 2019, 8:33 am

            Glyderm has used vitamin c esters.

  • Pedro May 23, 2014, 3:39 am

    An interesting not is these vitamin C derivatives in general (almost all were developed in Japan) are classified as “quasi-drugs” by the Japanese government. If a company wants to say the ingredient X is a “quasi-drug”, this company must send studies about the mechanism of action, safety, efficacy etc. to the Japanese gov. and wait for approval… It’s MUCH easier to approve a quasi-drug than a drug in Japan, but you still have to show some scientific evidence that the ingredient works. So, it’s not a drug, but it’s a bit more “serious” than just a cosmetic.

  • PinkCarnation May 23, 2014, 11:23 am

    After reading your article I googled and found this


    From the review this seem like a good product. Would you recommend this?? I am a little worried because the the Vit C percentage is 20% which you mentioned is the max amount. Your thoughts would be greatly appreciated.

  • Valentina May 23, 2014, 2:26 pm

    What should I look for as “stabilizing agent” if my serum contains water?

    • Randy Schueller May 24, 2014, 7:09 am

      Valentina: Paula Begon does a good of explaining the functions of ingredients in her products. Here’s an example of what to look for: http://www.paulaschoice.com/shop/collections/RESIST-Anti-Aging/_/RESIST-C15-Super-Booster/

      • Kerri August 29, 2016, 12:03 pm

        I know I’m late replying to this, but I’m just getting on the Vitamin C train now! The Paula’s Choice C15 and all the other top brands list water as the FIRST ingredient–does this mean we shouldn’t buy any of them? Many thanks!

        • Randy Schueller August 29, 2016, 9:29 pm

          Water as the first ingredient can be fine as long as the product contains stabilizing agents. Paula’s Choice is pretty good in this regard.

  • Ildiko May 26, 2014, 5:55 am

    Thank you for your proper answers, finally I had time to translate it properly. 🙂 Do you have some information about Tetrahexyldecyl Ascorbate? This is on the 3rd place in my favourite serum.
    http://www.paulaschoice.com/shop/skin-care-categories/antioxidants/_/RESIST-Super-Antioxidant-Concentrate-Serum Do you think is effective? It is an anhydrous system. It contains tocopheryl acetate, and ferulic acid. I read it makes a vitamin C product more effective. Unfortunately the Paula C15 Super Booster cannot buy in Europe.

    • Randy Schueller May 26, 2014, 9:20 am

      That version of Vitamin C wasn’t covered in the research paper that we found. In general, Paula’s products are well researched and formulated.

      • Ildiko May 27, 2014, 3:15 am

        Thank you for your answer! 🙂 You are like supersmart chemist heroes. 😉

      • Kim February 1, 2015, 2:24 am

        I use and adore multiple Paulas Choice products I received three of their Vitamin C serums in the trial size upon its release. The first one I opened turned Orange within seven days. I stopped using it moving on to another new Vitamin C product before moving back to Paulas Vitamin C trial. I opened it and it was already orange. I contacted their customer service who never addressed the fact it was ruined offering to send me another. I opened the third one – also stored in a dressing room cabinet still in its box too – and the third one was also Orange with a strong smell. meaning ruined as well. The Paulas Choice customer service was excellent refunding my cost of the one trial I had bought as the other two came as free gifts in two orders when they were being gifted with a purchase on her website. The refund was appreciated but no explanation on why this could’ve happened nor did anyone address whether it would be likely to happen in the full size bottle. I’ve now decided to ordr the SkinCeuticals Vitamin C product- expensive but noted by beautypedia as a good option. It is somewhat disturbing that the Paulas Choice product that comes from a site I rely on for solid honest info on product info yielded a seemingly bad product. Any idea why the trial size might’ve been bad perhaps the dropper system which she had always noted as not the preference for a delivery system? Now they have a video on their you tube channel noting a stopper that comes with the vitamin c product and my trial sixe had no stopper Perhaps the stopper is the key to preventing such fast breakdown? I appreciate your time and thoughts on this matter. And I am enjoying discovering more great info on this site as well.

        • Randy Schueller February 1, 2015, 8:18 am

          It’s possible that the packaging used on the trial size wasn’t a very good oxygen barrier. Some plastics allow oxygen to diffuse through them more than others. If this happened the oxygen could have reacted with the antioxidants in the formula.

        • Melissa February 14, 2015, 4:23 pm

          Im not sure if this will help, but I find that trial sized tend to be bottled and sit around much longer than the full sizes. I have not tried her water based serum but I’ve used Skinceuticals for many years. If you purchase directly from the Skinceuticals website, the serum will come in a light champagne color. Not ideal, but about as good as it gets for water based LAA. Store in fridge and it will keep well. Keep it in its box or in a dark compartment to keep light out as well.

          Many companies are making identical formulations with a slightly different PH, but for much cheaper. As for stability, its trial and error, but there are reviews and comparisons out there.

      • Ruth Ann Castillo March 12, 2016, 3:54 am

        Not formulated well if it has tetrahexyldecyl ascorbate! This stuff is cytotoxic, especially under sun exposure. It has an added fatty acid to the ascorbic acid molecule called palmitic acid, in order to enhance absorption through the lipid barrier. EWG is working to ban this stuff from sunscreens! I am surprised that this blog does not warn against this. The second reply to this article links to an article about bad vitamin c, here it is againhttp://feleciaroselabs.com/is-my-expensive-vitamin-c-serum-killing-my-skin/ And bloggers, please read this.

        • Anna Nabil November 11, 2018, 8:40 am

          That article by Felecia Rose has been debunked: http://www.educatedtherapists.com/2768-2/

          Vitamin C—including those that include palmitate—are not only safe, but also protective against cancer.

  • Ana Terra December 9, 2014, 5:12 am

    Hello, Randy,

    I would like to know which hour is better to apply the Vitamin C serum. Some people says at morning, before going out and other people defends that is better to use before going to sleep. I’ll be glad if you can help me.
    Bye 🙂

    • Randy Schueller December 9, 2014, 7:09 am

      Hi Ana. The time of day to apply vitamin C doesn’t matter in terms of how well it works. The only potential issue is that some people may find certain forms of vitamin C to be irritating and that irritation may be worsened with sun exposure. So, if you experience discomfort when using vitamin C try applying it night. If you don’t have that problem then anytime of day should be fine.

      • Melissa December 26, 2014, 7:47 pm

        Confused. If you are using it do defend against free radicals including sun exposure, perhaps smoke, and certain day time pollutions, then use it in the AM, yes? I realize there is no time that free radicals are not going to work on every part of us, but yeah that’s one of the points that C must pass so why waste it?. If all you care about it collagen promotion, use at night.

  • Melissa December 26, 2014, 7:41 pm

    I don’t think this question has been covered. Does ascorbly palmitate really promote cell damage/death when exposed to UVB radiation?
    This study would have me worried about that.

    Since ascorbly isotetrapalmitate is similar due to the palmitic acid, but penetrates even deeper than ascorbly palmitate due to the 4 palmitic attatchments, and if the first question is true, does it reason that ascorbly isopalmitate can do even more damage to the skin in the presents of UVB radiation? Tetraheclydecly ascorbic is now is EVERYTHING either along with AA or by itself and up to 30% concentrations of tetra-C, so this question needs some attention.

    Unfortunately the question of any type of vitamin c is more confusing than I think has been recognized here. Im certainly sickened with it as I don’t know how many years of using possibly harmful products and wasting money has gone on and what to do now. I’ve read in cosmetic derm journals that AA should not even be used in ANY cosmeceutical unless the patient mixes it them selves (Ive personally would not do this). Ive read that no one should ever attempt to mix themselves and only use medical grade products which I always have. But that is also contradicted by the fact that about 90% of the time a dermatologists office will sell me a product that has long oxidized, is orange, brown and gritty. Skinceuticals, Obagi, Glytone, Revision, DCL, they all have been sold to me this way and my understanding is that using oxidized vitamin c in any natural or derivative form is terribly pro oxidant NOT simply ineffective. YET, dermatologists offices will insist the oxidized product you just payed over $100 for is neither pro-oxidant or ineffective. Really? That’s the standard of their knowledge and passing along the manufacturers marketing dismissal is ok?

    Its always said that you should really be at least periodically under a derms supervision when using these products long term, and generally I agree. However, when I go to either try to evaluate the effectiveness of my skin care program or try to get help untangling the vitamin c mess, I find them to be incredibly uninformed.

    Please help.

    • Randy Schueller December 27, 2014, 9:18 am

      Thanks for the link to the Nature article, Melissa. Very interesting! According to the researchers, “The lipid component of ascorbic acid-6-palmitate probably contributes to the generation of oxidized lipid metabolites that are toxic to epidermal cells.” The lipid component comes from using the palmitate version of vitamin C so presumably using other forms that don’t have the lipid attached (like ascorbic acid) would’t cause the same problem.

      I share your frustration about getting to the bottom of this vitamin C mess. There is a lot of conflicting information and we tried to digest it and present the best of what we found in this podcast/blog post. The bottom line, as we said, is that the ascorbic acid version appears to have the best evidence. I’m afraid that’s about as much help as we can provide until we see further studies that say another form is better (or that AA shouldn’t be used at all.)

      If you find any more relevant studies, please let us know!

  • Melissa February 14, 2015, 4:04 pm

    Thank you very much for the response!

    That is something to keep in mind as more research is needed. Though I wonder how it performs on living skin with other antioxidants and sunscreen working with it, supposing you also use others besides vitamin C. Can’t say at this time from anything that I could find if it’s more beneficial than harmful (or if it indeed harmful at all), or the other way around.

    I’m also interested in delivery systems of vitamin C (and all actives really). I really like anhydrous silicone based LAA for stability reasons, and they don’t have to be formulated at low PH, nicer for dry skin. But I wonder how well they penetrate. There are various technologies to aid in that but I have a very limited knowledge of the different strategies for LAA and if they really work. Id love to know more about this.

    And one more confusing point. I thought I would give MAP a try at some point, but when looking for serums I find that magnesium ascorbyl phosphate has been referred to as magnesium ascorbyl palmitate. Are they the same thing, or is this an error? Too many derivatives to keep ones head on straight!

    The name keep coming! Oy..
    Disodium isostearyl 2-0-l-ascorbyl phosphate
    Sodium ascorbyl glucoside
    ascorbic acid-2-glucoside
    Methylsilanol Ascorbate
    methylsilanol ascorbate

  • Chris March 22, 2015, 8:38 pm

    You guys mention that ‘Tetra-C’ reduces pigmentation according to a trade journal. Is there reason to be skeptical of trade journals?

    • Randy Schueller March 23, 2015, 8:21 am

      Yes. Trade journals usually feature articles written by the companies that sell the ingredients and the articles are not peer reviewed. This doesn’t automatically mean the research is bad it just means that it may be biased and hence you should be skeptical.

  • wendy April 5, 2015, 10:49 pm

    Thanks for this fantastic article. I have a question regarding topical AA powder. I’ve been using this product http://www.sephora.com/turbo-booster-c-powder-P204606 for a few weeks now. The instructions advise that the product should be mixed with moisturizer. I’ve been mixing it with coconut oil since I don’t use conventional moisturizer.
    My question is, is AA soluble in oil? Will it penetrate the skin in an oil vehicle?

    • Randy Schueller April 6, 2015, 9:28 am

      Hi Wendy. Ascorbic Acid is not oil soluble so using coconut oil is not an ideal vehicle.

      • Michelle July 19, 2015, 11:21 am

        Hi Randy,
        could this Philosophy Turbo Booster C Powder be mixed with Paula’s Choice Resist Super Antioxidant Concentrate Serum? Would this be a good vehicle for powder vitamin C?

        • Randy Schueller July 19, 2015, 5:26 pm

          If you post the ingredients I’ll take a look at it.

          • Michelle July 22, 2015, 6:37 pm

            Hi Randy,
            the ingredients are:
            Key Ingredients: glutathione, epigallocatechin gallate, coenzyme Q10, turmeric, skin-repairing ingredients, thioctic acid, ceramide NP, soy extract, Arctostaphylos uva ursi leaf, ferulic acid, cell-communicating ingredients, tocotrienols, beta-glucan, glycerin, vitamin C, tocopherol, Curcuma longa root, ergothioneine, xanthophyll, vitamin E, palm oil, superoxide dismutase, ubiquinone, palmitoyl tripeptide-5, antioxidant

            Product Ingredients:
            Cyclopentasiloxane, Dimethicone (silicone slip agents/suspending agents). Tetrahexyldecyl Ascorbate (stabilized vitamin c/antioxidant), Palmitoyl Tripeptide-5 (cell communicating ingredient), Ceramide NP (skin-repairing ingredient), Tocotrienols, Tocopherol (vitamin e/antioxidant), Ubiquinone (coenzyme q10/antioxidant), Thioctic Acid (alpha lipoic acid/antioxidant), Tocopheryl Acetate (vitamin e/antioxidant), Magnesium Ascorbyl Phosphate (stabilized vitamin c/antioxidant), Ferulic Acid (antioxidant), Beta-Glucan (anti-irritant), Superoxide Dismutase (antioxidant), Epigallocatechin Gallate (green-tea derived antioxidant), Ergothioneine (mushroom derived antioxidant), Glutathione (fruit derived antioxidant), Xanthophyll (antioxidant pigment), Glycine Soja (Soybean) Seed Extract (antioxidant), Glycerin (skin identical ingredient), Arctostaphylos Uva Ursi (Bearberry) Leaf Extract (anti-inflammatory agent), Lupinus Albus Seed Oil, Curcuma Longa (Turmeric) Root Extract (antioxidant), Elaeis Guineensis (Palm) Oil (emollient), Phenoxyethanol (preservative).

  • Nathalie B April 29, 2015, 3:52 am

    Hi Randy,
    I’m a french lady passionated by Vitamin C…
    I was very happy to find your blog and to read all those interesting information about this active ingredient. Here in France, a lot of people think that Vitamin C is photosensitizing and are scared to use it under the sunlight. Have you ever seen a publication on this side effect?
    In your demonstration you mentionned a publication: “Stability, transdermal penetration and cutaneous effects of ascorbic acid and its derivatives” from the Journal of Cosmetic Dermatology, 2012. I cannot find it on the web…do you know where I can get it?
    Thank you very much for all you’ve done and written…Hope to read you soon for further information


    • Randy Schueller April 29, 2015, 7:08 am

      Hi Natalie. Not all of the Journals we cite are online (and some are online but require a paid membership.) Sorry! Does Vitamin C cause sun sensitivity? I can’t find any proof of that. It’s true that if you ingest a lot of vitamin C it can interfere with the absorption of B vitamins that help protect your skin from the sun. It’s also true that citrus fruits (which contain vitamin C) can increase sun sensitivity but it’s the components in the citrus oils causing the problem, not vitamin C. (As far as I’ve been able to determine.)

      By the way this might be a good question for us to discuss on our podcast. Would you be interested in recording an audio version of your question for us? If you are, just record it on your smart phone and email it to me at thebeautybrains@gmail.com. Thank you!

  • Naomi June 11, 2015, 9:40 am

    Hi Randy. I’m interested in making my own vit c serum but I’m not sure where to get AA. Is L-Ascorbic Acid a special type of AA or just another name for it. And can I trust AA powder used for biology experiments, the one sold by lab suppliers for my serum? Also is that AA super fine?Hope to hear from you soon.

    • Randy Schueller June 11, 2015, 10:47 am

      Hi. I don’t deal with sources for consumer quantities of cosmetic ingredients but there are a lot of DIY sites out there that may help you. You might also be able to get additional information at our sister site, http://www.chemistscorner.com.

      Good luck in your search!

      • Clara February 2, 2019, 7:20 am

        Hello Randy/Perry,
        Some youtube beauty bloggers posts about DIY vitamin C face mask, serum etc. But after reading some literatures on your valued this site, I do not feel safe for that. In this regards, please explain some bad or good points about using citrus juice (e.g. lemon juice) to perform face mask; mixed with whole egg mixture, oil, honey, etc. That specific mixture or other types of mixture which use lemon juice as AA ingredient, will be harmful or really effective for facial skin etc. I’m really expecting your reply and appreciating both of your valued contributions to people. Thanks a lot!

  • Eva July 28, 2015, 6:29 pm

    This is what I have been doing, mixing a large pinch of micronised L-ascorbic acid powder with several drops of low pH toner ( say 0.2ml, ph2.9), then immediately rub the compound onto the skin. Yes. It irritates moderately, certain patches of my skin turns red immediately but settles overnight. I believe I’m seeing benefits on my skin. Am I just imagining the benefit or do you think it is a reasonable option? The product may not be stable but I’m applying on my bare skin immediately.

    • Randy Schueller July 29, 2015, 8:33 am

      @Eva: That seems like a reasonable approach as long as it’s not irritating your skin too much.

      • Marie September 20, 2015, 8:19 pm

        Eva, I was hoping you might share where you find your micronised L-ascorbic acid powder and pH toner? I would like to try the DYI approach to Vitamin C, but worry about suppliers. I would be grateful for your direction!

        And Beauty Brains guys, WOW! Thank you!!!! I love this site!!!!

        • Randy Schueller September 21, 2015, 7:12 am

          You’re welcome! (you can return the favor by writing a review for us on iTunes.)

    • Ruth Ann Castillo May 31, 2016, 9:16 am

      This is for Eva, Hello Eva,
      I too would really like to know where you get your micronised L ascorbic acid powder, please! I guess this is the only way to go and I am happy to hear that you are getting good results with your vitamin c regimen. So I hope you will let us know what it is and where to buy it. Thanks a bunch! Ruthy C

  • GraceK August 10, 2015, 8:29 am

    Can vitamin C react with the iron content in make up? For example iron oxides, Ferric ferrocyanide, Ferric ammonium ferrocyanide etc

  • Sharon September 4, 2015, 10:16 am

    Just wanted to say thank you for all this great information! So intelligent and thorough – very refreshing! I’ve been surfing for info on topical C and AHAs this morning and been dismayed to find only pat little articles with no substance until this – WOW ! I literally sighed with relief – now HERE’s some REAL information! So grateful for your work in the world!

  • Nita September 21, 2015, 12:34 pm

    Hi. I live in a hot humid city -Mumbai, India. I want to buy Vit C from USA or London but worry that because of its unstable nature, over time it may discolour in Mumbai. Please advise between serum and powder which will have a longer shelf life and also which brand should I buy. I am 58 year old.Thanks

  • jaynes123 September 30, 2015, 4:49 am

    TIMELESS 20% Vitamin C + E Ferulic Acid Serum
    Since water is listed as first ingredient (below), can you tell if a stabilizing agent (as you recommended) is included among other listed ingredients? Paula’s C15 lists sodium Metabisulfite as a stabilizer
    Wondered if the “Sodium Hyaluronate” also is one or just sounds similiar.

    Water, Ethoxydiglycol, L-Ascorbic Acid, Propylene Glycol, Alpha Tocopherol, Polysorbate 80, Panthenol, Ferulic Acid, Sodium Hyaluronate, Benzylalcohol, Dehydroacetic Acid.

    • Randy Schueller September 30, 2015, 8:13 am

      Sodium Hyaluronate is another moisturizing agent it does not stabilize vitamin C like the metabisulfite does. The main stabilizing agent appears to be ferric acid. Read this article if you want more details: http://www.nature.com/jid/journal/v125/n4/full/5603565a.html

      • Sandra Adamson February 22, 2016, 7:29 pm

        Based on the Timeless ingredient list posted, is this a good alternative to Paula’s Vitamin C serum? The price difference is $11 when you can catch it on sale and $23 when it’s not on sale. Thanks

        • Randy Schueller February 23, 2016, 9:33 am

          Based on the the ingredient lists the two do appear to be comparable. I notice that Paula has more stabilizing agents but I’m not sure how much of a difference that would make.

          Ingredient lists:

          Water, Ethoxydiglycol, L-Ascorbic Acid, Propylene Glycol, Alpha Tocopherol, Polysorbate 80, Panthenol, Ferulic Acid, Sodium Hyaluronate, Benzylalcohol, Dehydroacetic Acid.

          Paula Resist C15 Serum:
          Water, Ascorbic Acid (vitamin C/antioxidant), Ethoxydiglycol (slip agent/penetration enhancer), PPG-26 Buteth-26 (emulsifier), PEG-40 Hydrogenated Castor Oil (thickener), Tocopherol (vitamin E/antioxidant), Ferulic Acid (antioxidant), Sodium Hyaluronate (skin-repairing ingredient), Acetyl Octapeptide-3 (cell-communicating ingredient), Glycerin (skin-repairing ingredient), Panthenol (skin conditioning agent), Sodium Metabisulfite (stabilizer/antioxidant), Triethanolamine (pH adjuster), Phenoxyethanol (preservative).

          • Ruth Ann Castillo March 12, 2016, 4:54 am

            I have been using Paula’s Choice vitamin c serum, and I was putting it in the frig and using it from there. Now, under the ‘FAQ’ caption on the product page of her site, she says not to put it in the frig, that it is formulated to be stable and to last, and that by putting it in the frig it is detrimental to the stability of the carefully calibrated vitamin c serum. So now, I do not put it in the frig, and it starts to get yellow before 30 days are up. When I did put it in the frig, it stayed clear for 5 months. Is what she is saying true? Or are they worried about decreased orders for the product if it stays stable for long periods of time in the refrigerator? Thanks a bunch!

  • Evelyn October 25, 2015, 2:18 am

    I wish I had read this before purchasing Vitamin C serum! If the ingredients of the one I bought are:

    Water, Organic Green Tea(Camila Sinesis), Glycerin, Propylene Glycol, Aloe Barbadensis Leaf Extract, Vitamin C Glucoside, Vitamin C (Ascorbic Acid), Hops (Humulus Lupulus). Rosmary (Rosmarinus Officinalis), Leaf Extract, Witch Hazel (Hamamelis Virginiana) Leaf Extract, Sage (Salvia Officinalis) Leaf Extract, Horsetail (Equisetum Arvense) Extract, Lemon (Citrus Limonum) Peel Extract. Scots Pine (Pinus Sylvestris) Bud Extract, Hyaluronic Acid, Pelargonium Graveolens Oil, Vitamin E, Methylsulfonylmethane, Simmondsia Chinensis (Jojoba) Seed Oil, Carbomer, Triethanolamine. Phenoxyethanol, Caprylyl Glycol, Potassium Sorbate, Hexylene Glycol.

    should I go ahead and return it since water is the first ingredient (most likely the wrong pH then)?

  • Natalie November 9, 2015, 10:53 pm

    I always thought vitamin c should be used during the day, not night. Best analogy I ever received was the ol avocado lemon example. Just as lemon juice protects food, such as an avocado, so too would vitamin c protect the skin from the free radicals in the environment. Repair products (not that c doesn’t repair) should go on at night, such as vitamin A, (that’s another subject though). Thanks

  • Natalie November 9, 2015, 11:18 pm

    I recently came across a skincare line that claims they do use the same type of vitamin c most lines use. They use a white orange grown in France or something. Anyway, point it, vc will NOT oxidize. Therefore, they can use higher percentage of vc with worrying about oxidation.

    • Perry November 10, 2015, 9:55 am

      If the chemical is not oxidizing then it isn’t Vitamin C. The fact that it comes from a white orange grown in France is irrelevant.

  • Kerrie November 30, 2015, 10:28 am

    One question I cannot seem to find a direct answer to, “Is there a difference between Ascorbic Acid and L-Ascorbic Acid when it comes to topical solutions?”
    I had heard that the generic term for VC on a product label can be Ascorbic acid but that L-AA is specific. Is there any truth to this?

  • Star Light November 30, 2015, 12:19 pm

    Why are essential oils with Vitamin C not mentioned? They are much more stable, there are many which are very unlikely to cause negative reactions, and Do cross the skin barrier. Which essential oils are the best for adding vitamin C to the skin? How do they compare to the powders you are mentioning in reguards to aiding the skin?
    PLEASE research before you reply, because I can see that before I mentioned this it has not been looked into. However, I am curious what you will come up with AFTER research.
    Thank you in advance.

    • Randy Schueller November 30, 2015, 3:30 pm

      I’m intrigued by what you say about essential oils with Vitamin C being more stable, less likely to cause negative reactions, and better able to cross the skin barrier. I’ve never heard that before and would like to learn more. Can you point me to some studies which back up what you say? Thanks!

  • Tracy Regan December 3, 2015, 9:34 pm

    There is a popular DIY vitamin c serum on the internet which consists of a mixture of powdered AA dissolved in distilled water then mixed with glycerin.
    But I’m a little confused, as this article has pointed out that AA can begin to oxide when dissolved in water. Does this mean the DIY serum is ineffective?

    • Randy Schueller December 4, 2015, 9:02 am

      It’s possible. It depends on how quickly you use the serum after mixing it and if there are any stabilizing agents included.

  • vivan December 15, 2015, 2:29 pm

    after washing face and then applying l ascorbic acid serum should you wait to apply hydrator on top… 3, 5, 10 minutes etc?
    what happens if you apply l ascorbic acid without washing face first? thx

    • Randy Schueller December 15, 2015, 7:05 pm

      I haven’t seen any data that says exactly how long you should wait. I assume if you apply vitamin C to unwashed skin it uses up some of the antioxidant capacity of the lotion more quickly. That’s just my guess.

  • Johnnie February 3, 2016, 7:16 pm

    Could u give me a DIY formula for vitman c serum and hyaluroic acid. In 5. 10. 15. 20. Percent. Would like to make my own. Thank you

    • Randy Schueller February 3, 2016, 9:34 pm

      Hi Johnnie. We don’t really do formula consolation but maybe one of our other readers can steer you in the right direction. You also might check out our sister website http://www.chemistscorner.com for formulating tips.

  • Sandra February 23, 2016, 7:06 am

    I just listened to this podcast again. You site Paula’s website in a lot of your podcasts. My first question is. 1. Can you look at this product?

    It’s 25% vitamin C in a silicone base. I thought that 20% was the maximum amount that skin can penetrate? 2. http://www.timelessha.com/20-vitamin-c-e-ferulic-acid-serum-1-oz/
    is this a good alternate formula despite the amount of Benzylalcohol?

    • Randy Schueller February 23, 2016, 9:20 am

      We didn’t say that 20% is the maximum amount that can penetrate skin – we said that 20% is (supposedly) the optimal level for absorption. Perhaps Paula formulated a little above 20% to compensate for degradation of the ascorbic acid? I’m not sure.

  • Maya February 28, 2016, 5:43 pm

    Dear Perry and Randy, many thanks for your webinars, podcasts and forums!
    I do make my own C serum with Ascorbic Acid, pretty much the Neutracuticles recipe, and just make a new batch every couple of weeks, although it remains white all along and past 2+ weeks. I did accidentally purchase the water soluble vit E powder (dl-alpha tocopheryl acetate), which turns white when mixed with water and helps watching for discoloration due to time and oxidation.
    However I can’t help wondering if this form of vit E is as potent as the oil.
    I’ve not been able to find much info as to how the two vit E forms measure against each other or in combination with Ascorbic Acid or anything else for that matter…
    Most importantly, considering the ultra fast deterioration of Ascorbic Acid when exposed to liquid, let alone light and heat, I’ve always treated mine , appropriately enough, as a treatment rather than leaving it on and adding a lotion on top. I leave it on for about 20 minutes or so, wash it off and proceed with my day/night lotion.
    What gives, please? Am I washing it off too fast?

    • Randy Schueller February 29, 2016, 7:38 am

      My understanding is that vitamin C treatments work best when delivered from leave on products. I havent seen hard data on this but ‘t seems like washing it off, even after 20 minutes, would reduce the amount that’s absorbed into your skin.

  • Ruth Ann Castillo March 14, 2016, 6:47 pm

    please look at this article about the dangers of this liposome encapsulated vitamin C, i.e. Ascorbyl palmitate http://www.jidonline.org/article/S0022-202X(15)30060-9/fulltext
    Thank you.

    • Randy Schueller March 15, 2016, 8:36 am

      Very interesting – I had heard about this but I had not actually read the study. Although it’s only a single piece of research and it was done on cell cultures, it does establish a mechanism by which ascorbyl palmitate could react with UVB and damage skin. (Assuming that enough of the material penetrates through the skin.)

  • Gili March 29, 2016, 6:49 pm

    what are your thoughts about combining vitamin C with vitamin E?
    I am so confused. On a search for a vitamin C serum that will be free from any chemicals or hazards, and will not damage my skin…

  • ginan April 5, 2016, 12:04 pm

    Hi Randy,

    Here are 2 more studies (in addition to the one Ruth Ann Castillo posted above on 3/14) that an article I ran into cites as as proof that some forms of Vitamin C are really dangerous in sunscreens (like ascorbyl-palmitate) and that basically you should avoid any sunscreens or Vitamin C serums that use these types of vitamin C.


    I have some sunscreens (one of them a lip balm) that list Ascorbyl Palmitate pretty high up on the ingredients list. :/

    Just wanted to add those 2 studies and wondering if after looking at them you would come to the same conclusions or questions about the safety of some of these forms of vitamin C especially in sunscreens or anything that’s going to interact with the sun.


    • Randy Schueller April 6, 2016, 7:16 am

      Thanks Gina. Perry and I will take a look at these.

      • Rachel Bailey De Luise May 27, 2016, 1:14 pm

        Has there been a follow-up to this thread of questioning? It sounds like there are lots of us hoping to hear what products are actually “safe” to use, out in the sunlight? For a few years, I have applied my vitamin C (containing palmitate) in the morning (assuming that it was additional protection from UVs), only to find out that it is doing more harm than good to my skin cells. It would be great to have a follow-up SOON and an alternative or “pure” product recommendation that we can use. Thanks!

        • Randy Schueller May 27, 2016, 2:49 pm

          Sorry but I haven’t seen any further studies that would clarify this issue.

          • Nicole October 5, 2016, 9:37 am

            I would like an update too regarding the thread about the “alleged dangers” of Ascorbyl Palmitate as well. I just read the article from http://feleciaroselabs.com/ and I’m concerned because I am currently using a product that is composed of a stabilized form of Vit C (Ascorbyl Palmitate). The name of the product is Klairs Freshly Juiced Vitamin Drop Serum. It’s being hailed as one of the holy grail products by the Asian Beauty / K-beauty community.

            I had read rave reviews about the product lightening hyperpigmentation, clearing acne scars and brightening the skin tone. At the same time, some say that nothing has happened to their skin, because the product doesn’t have that low of a pH to be an exfoliant. I also haven’t heard or read any ill effects of this serum.

          • Nicole October 5, 2016, 10:21 am

            I might as well have answered my own question (LOLZ).

            Incidentally, I stumbled upon this article that might ease some of the anxiety regarding Ascorbyl Palmitate: https://www.truthinaging.com/review/the-truth-about-ascorbyl-palmitate-and-cancer

            I have read the studies posted in this thread and what I understand is that it’s all done in vitro. Sometimes experiments done in vitro do not translate well in vivo. Having that said, it’s sad (and quite annoying) that follow up studies have not been done regarding this. It hasn’t been replicated either.

            My take on all of this is that, if you are still uncertain and you don’t want to take the risk, you have the prerogative to discontinue all products containing Ascorbyl Palmitate. In my case, unless there are more studies proving its harmful effects, I would very much like to keep using my Klairs Vitamin C Serum thankyouverymuch. 😉

  • ginan April 7, 2016, 12:51 pm

    Thank you, Randy and Perry. I think one of the studies that Ruth and I posted are actually the same, from November 2002. Sorry about that. :/

    I tried to look for other studies but didn’t find any that seemed to cover the same topic (or at least as far as I could tell.)

  • Susan April 27, 2016, 9:13 pm

    Hi Perry and Randy. Thanks for your time and effort on this website.

    I just wanted to ask how an anhydrous vitamin c product can penetrate the skin. This vitamin c product by Indeed Laboratories (ingredients: dimethicone, ascorbic acid, polysilicone-11, ethylhexyl palmitate, peg-10 dimethicone, silica silylate, silica dimethyl silylate, butylene glycol, sodium hyaluronate) has 22% LAA and 2% hyaluronic acid.

    From my understanding, the hyaluronic acid will bring water from within the skin to the epidermis and allow the water soluble LAA penetrate the skin. Is this correct? And what do you think of the formulation of this product?

    Looking forward to your reply,

    • Randy Schueller April 28, 2016, 7:42 am

      Hi Susan. This formula uses a very effective version of Vitamin C at a high concentration. LAA has been proven to penetrate skin. It doesn’t need the hyaluronic acid to do that. Hyaluronic acid can bind large amounts of water but it does not pull it from the skin like glycerine can.

  • Em May 11, 2016, 8:32 am

    Hi and thank you for all your help and advice.
    I am wondering if it’s possible and safe to make my own Vitamin C solution. I have found several PURE Magnesium Ascorbyl Phosphate powders online, see an example here:
    I am however wondering whether these are safe to make and how to do that. Can you help? Thanks a lot.


  • Marie Gross June 3, 2016, 6:54 am

    What about Tetrahexyldecyl Ascorbate? I did not see if on the list. Can you point out the difference between MAP, Tetrahexyldecyl and Ascorbyl Tetra-Isopalmitate? Any preference of one over the others?

    • Randy Schueller June 3, 2016, 10:22 am

      The papers we reviewed didn’t assess tetrahexyldecyl ascorbate.

  • Arpan Dutta June 18, 2016, 7:08 am


    I was just wondering what you think about Tetrahexyldecyl ascorbate/ascorbyl tetraisopaamitate’s use during day light hours? Since this is also a fat soluble Vit. C does it have the same ill effect of Ascorbic Palmitate?

    I shall very much appreciate your views on this. I am totally confused with the constant release of new variants of Vit C, obviously not all of which are safe!

    Thank you so much

  • Clair July 7, 2016, 8:14 am

    I love this article – your detailed explanation of all the different vitamin C derivatives as well as the readers’ contribution. What a site!
    Thank you for sharing with us your brains and helping us to make better beauty decisions!

  • Brian July 12, 2016, 11:18 pm

    Hi Randy, I’ve been trying to find usage amount ( range) for Sodium Metabisulfite, and am not having any luck. Can you advise at all please?

    • Randy Schueller July 13, 2016, 7:12 am

      Offhand I don’t know but you can find some useful info here. You’ll have to register to get the details but I think this will help. http://cosmetics.specialchem.com/inci/sodium-metabisulfite#Formulations

      • Brian July 14, 2016, 12:04 am

        Thank you

      • Brian July 20, 2016, 9:01 pm

        Randy, Would you be so kind as to shed some light on why it is likely the following reaction happens?
        When I make the following serum (formula is from Lotion Crafters and is a DIY copy of Skinceuticals C&E with Ferulic Acid)
        When I include 0.02-0.05% of sodium metabisulfite (having tried adding at the start just after the EDTA, or at the end, why does it increase the viscosity of the product from serum to stiff jelly? ( which was permenant )
        I checked the pH at all stages and there was no significant change specifically from adding the Sodium Metabisulfite.
        I’m so interested as to what is Sodium Metabisulfite is doing?

        Thanks in advance.

        Phase A
        46.05 Distilled Water
        0.035 Triethanolamine
        0.050 Ferulic Acid
        0.050 dl-Panthenol

        Phase B
        0.10 Hyaluronic Acid

        Phase C
        20.00 Ethoxydiglycol
        10.00 Propylene Glycol
        3.00 Glycerin
        3.00 Laureth-23
        1.00 d-Alpha Tocopherol or 95% Mixed Tocopherols
        0.50 Phenoxethanol

        Phase D
        15.00 L-Ascorbic Acid Ultra Fine Powder

        Phase E
        Q.S. Triethanolamine or Citric Acid Solution 50%

        • Randy Schueller July 21, 2016, 7:19 am

          Very interesting! I wonder if the bisulfite could be causing some cross linking…but with what? Hmmm. You might try posting this in the Lotion Crafters forum to see if anyone’s solved this problem. You might also consider asking this on Chemists Corner (www.chemistscorner.com), our sister site.

          • Brian July 22, 2016, 8:58 pm

            If so, It could only be with the HA, nothing else in there that could. right?
            I will do as you suggest and post to Chemistcorner. Thanks Randy

  • EM July 22, 2016, 6:04 am

    If the moderators are still reading this thread, I was wondering if you could weigh in on 4 Vitamin C serums that I am considering. I understand much has to do with their formulation & ph, but aside from those, how do the percentages of the various Vit. C derivatives relate?

    1. Reviva – 7% magnesium ascorbyl phosphate
    2. John Masters – 0.5% ascorbic acid polypeptide
    3. Sanitas – 12% ascorbyl palmitate
    4. Mad Hippie – 10% sodium ascorbyl phospate


    • Randy Schueller July 22, 2016, 7:46 am

      Of these 4, the best data exists for the 3.) ascorbic palmitate and 4. sodium ascorbyl phosphate. I’d pick which ever one is cheaper and try that.

  • Anthi August 1, 2016, 3:41 am

    Hello! This is a very helpful article. If you wouldn’t mind taking a look, what you think about this formula? Thank you! http://www.lotioncrafter.com/formulary/Double_C_Serum.pdf

    • Randy Schueller August 1, 2016, 8:52 am

      Very interesting. It certainly could be worth a try.

  • Becky August 2, 2016, 11:23 am

    You said you should wait after applying a VC product before applying any other products. Can you apply any products before VC without causing oxidation, or should you apply VC to a bare face? I usually apply a BHA as the first step in my skin care routine – could I apply VC immediately after that? Thanks!

    • Randy Schueller August 3, 2016, 7:03 am

      The best approach is to allow some time between applying Vit C products and products containing potential oxidizing agents.

  • Eugene August 18, 2016, 6:12 pm

    Hi! Big fan of your blog and comment section too. Thank you for your great work!

    I would like to ask about heating Ascorbic Acid in water-free solutions, for example if I heat Ascorbic acid in propylene glycol would it oxidizes and turn yellow or not?

    Thank you in advance!

  • SkincareJunkie September 9, 2016, 6:48 pm

    Hi, Randy, I just came across this article and I have question about Ethylated Ascorbic Acid. I found a vitamin C serum that has a concentration of 25% Ethylated Ascorbic Acid. Since Ethylation keeps the highly unstable Ascorbic Acid stable, does that mean that you will absorb the full 25% or does it still stand that I will absorb less, since it’s over the maximum of 20%. I’m really interested to hear your thoughts on this. Big fan, thank you!

  • Sophiya September 19, 2016, 9:31 am

    Hi Randy!

    I love how informative this article is and I’m really interested to know if the vitamin C serum I’m using is potent. I’m currently using Avalon Organics’ Intense Defense with Vitamin C Facial Serum. Ingredients include water and ascorbic acid. I believe the full list of ingredients may be found on their website. Any thoughts?

    Thank you and more power!

  • najwa October 23, 2016, 11:22 am

    First, Thank you for all that you do!
    Second, I found the following information (Please, see below) on the OZnaturals website, the FAQs section. I would appreciate it, if you could please take a look, and let me know what you think. Is their claim legit?
    Why does OZNaturals choose to use Sodium Ascorbyl Phosphate instead of L Ascorbic Acid?
    Sodium Ascorbyl Phosphate is proven to be much more stable, and have a higher bioavailability than L Ascorbic Acid. While historically lab tests stated that LAA was the best form of Vitamin C serum for your skin, BASF scientists now show newer test results discounting those findings. LAA is highly unstable and will lose its potency very quickly unless mixed with harsh preservatives. Our superior SAP formulation is so much more stable and potent than LAA that we provide a guaranteed 2 year shelf life without any harsh preservatives. This is something no other Vitamin C serum can currently provide. Also, Our Vitamin C is made weekly in fresh batches, so there is no chance that your bottle has lost any potency. On average our bottles sit less than 7 days before being purchased.

    Thank you for your time.

  • Gigi November 4, 2016, 5:01 pm

    Hi Randy,

    I would love to read this post “Why it can be Disastrous to use the Wrong Vitamin C” but I have trouble to find it. Would you please post the link?

    Thanks for all you guys have done.


    • Randy Schueller November 6, 2016, 8:34 am

      I’m confused Gigi, are you asking about a post we wrote? Honestly, I don’t remember that title.

      • Gigi March 18, 2017, 3:50 pm

        No, my apologies. It was from a comment on this post. I wasn’t paying attention, sorry.

  • FrenchBeautista December 6, 2016, 5:34 pm

    Best post ever. So helpful!
    If I use ascorbic acid as a serum, how many times should I wait before applying my night cream?

    Thank you <3

  • Alex January 20, 2017, 11:59 am

    There is a new brand being distributed in US, called Medskin Solutions by Dr. Suwelack. This is a German Dr. who created a *cryogenic technique, and has freeze dried Vitamin C (spheres). It stable because its freeze dried and hence doesn’t need preservatives. Its activated daily by a solution (so its a 2 step system). So you are getting an *effective, measured daily dose, which is highly effective. I love it. No water, no degradation, no preservatives, and delivers Amazing Results. Vitamin C is great!

  • Beth March 15, 2017, 2:56 pm

    Glad I found this site. This information was very helpful!

  • Rick Fox March 22, 2017, 9:00 am

    Thi is the one we are using. https://www.truthinaging.com/ingredients/tetrahexyldecyl-ascorbate

    Apparently no data. Thoughts, Perry?

  • Bryony April 11, 2017, 4:22 am

    Just wanting your thoughts on the formulas of
    1) Drunk Elephant C-firma
    2) MooGoo Super Vitamin C Serum

    One is significantly cheaper so I was wondering about the potential effectiveness them both.


    • Randy Schueller April 11, 2017, 7:56 am

      I’m sorry but I don’t have time to track down these products. If you post the ingredient list to each of them I’ll try to review them for you.

      • Alysha April 18, 2017, 1:38 pm

        Drunk Elephant: (L-AA + Ferulic + E)
        Water, Ethoxydiglycol, Ascorbic Acid, Glycerin, Laureth-23, Lactobacillus/Pumpkin Ferment Extract, Sclerocarya Birrea Seed Oil, Ferulic Acid, Sodium Hyaluronate, Chondrus Crispus Extract, Camellia Sinensis Leaf Extract, Lactobacillus/Punica Granatum Fruit Ferment Extract, Glycyrrhiza Glabra (Licorice) Root Extract, Vitis Vinifera (Grape) Juice Extract, Phyllanthus Emblica Fruit Extract, Hydrolyzed Wheat Protein, Tocopherol, Caprylhydroxamic Acid, Acetyl Glucosamine, Hydrolyzed Quinoa, Glutamylamidoethyl Imidazole, Dipotassium Glycyrrhizate, Tetrahydrodiferuloylmethane, Tetrahydrodemethoxydiferuloylmethane, Tetrahydrobisdemethoxydiferuloylmethane, Sodium Hyaluronate Crosspolymer, Glycine, Sucrose, Maltodextrin, Propanediol, Caprylyl Glycol, Sodium Hydroxide, Xanthan Gum, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Isohexadecane, Polysorbate 60.

        Simmondsia Chinensis (Jojoba) Seed Oil, Squalane, Olive Oil Decyl Esters, Ascorbyl Tetraisopalmitate, Tocopherol, Panthenol.

        • Randy Schueller April 19, 2017, 8:32 am

          The Drunk Elephant product appears to have a higher level of a more active ingredient. (ascorbic acid vs Ascorbyl Tetraisopalmitate.)

  • Debra Stewart April 17, 2017, 12:05 pm

    I looked through the questions and could not find an answer to my question. I recently bought L-ascorbic acid powder, ugh, but my package says FOOD GRADE. Can I still use this in my Vitamin C serum recipe??? I’m pressed for a quick response if you can. Thank you.

    • Randy Schueller April 18, 2017, 7:53 am

      Yes, food grade ingredients can be used in cosmetics.

  • Karen Lee May 6, 2017, 4:49 pm

    I use this product by Ultraceuticals (Australian) and would like your thoughts on its ingredients – good formulation?

    Ultra C23+ Firming Concentrate

    It’s expensive but I feel it works and is 23% pure Vitamin C

    Ingredients: Dimethicone, AscorbicAcid, Cyclopentasiloxane, C12-15 AlkylBenzoate, Dimethicone/VinylDimethicone Crosspolymer,Polysilicone-11, EthylhexylHydroxystearate, Dipropylene GlycolDibenzoate, HydroxyethylAcrylate/Sodium AcryloyldimethylTaurate Copolymer, Tocopherol,Palmitoyl Hexapeptide-12, PalmitoylTripeptide-1, Palmitoyl Tetrapeptide-7,Ceramide 2, PPG-15 Stearyl EtherBenzoate, Tribehenin, Glycine Soja(Soybean) Oil, PEG-10 Phytosterol,Acetylated Glycol Stearate, SorbitanLaurate, Salicyloyl Phytosphingosine,Tristearin, Citrus Aurantium Bergamia(Bergamot) Fruit Oil, Citrus Grandis(Grapefruit) Peel Oil, Lactic Acid,Linalool, Limonene.

    • Randy Schueller May 7, 2017, 8:04 am

      It appears to be a reasonable formula. If you like it and you can afford it then keep using it.

  • Becky May 7, 2017, 3:04 pm

    So based on this article, The Ordinary’s 25% LAA-product is the best product (as it contains LAA in an anhydrous formula)? I have heard conflicting things, some people saying their 20% AT in vit F solution penetrates the skin better and is thus more effective. I am mostly interested in collagen synthesis, for what it’s worth.

    • Randy Schueller May 8, 2017, 6:57 am

      Based on the evidence we’ve seen, yes, 20% LAA in an anhydrous or other well stabilized base is the best.

      • Pete February 18, 2018, 9:56 am

        How does it work with their 30% LAA suspension in silicone? Wouldn’t the silicones impede absorption of the vitamin C and any subsequent products?

        • Perry Romanowski April 3, 2018, 8:30 am

          Not necessarily. You would have to test it and see.

  • Tina May 19, 2017, 10:58 pm

    I wonder, is it more advantageous to your skin to combine different forms of topical vitamin C or would this too much for ones skin handle long term verses one or the other?. I have been mixing two drops of a 20% Ascorbyl Tetraiopalmitate (oil formulation), 10% MAP (cream formulation) and a 12% Ascorbyl Glucoside (water based formulation) to my face, neck and décolletage.

  • Brigadoon August 23, 2017, 3:03 pm

    I use Trader Joe’s Powder Vit C (AA) : After I cleanse my face with Clinique Bar soap, pat dry – I put a small amount of Trader Joes Vit C powder in my hand – add a very small splash of water rub my hands together and quickly apply the granuals to my face gently using it as a scrub – wait a full minute – then rinse – then apply my Clinique Clairfying #2 & the DDML+ moisture – My question is: will this stimulate the production of collagen in my skin? -( My skin glows and feels very hydrated)

    • Randy Schueller August 24, 2017, 7:32 am

      Vitamin C needs to be left on the skin to be effective. Just rubbing it on for a minute and then rinsing is not going to do much.

  • Hana October 16, 2017, 12:06 pm

    I used the ordinary 23% L ascorbic acid, it had a gritty feeling so I was spraying water mist on my face before to disolve it, I am not sure I was getting the maximum benefits out of it. Now the ordinary launched a 30% L ascorbic acid in silicone but I am wondering it is has any benefit because the product is supposed to disolve in water and it doesn’t do that in silicone, it makes it more stable as a formula but is it the best for the skin

  • Martha December 7, 2017, 12:08 am

    Hello! I would like to ask a question: how long does it take for anhydrous Vitamin C formula (~20-25%) to be fully absorbed into skin and then washed off? I have a problem with water formulas, they irritates my skin, when serums without water works great, but they usually leave very unpleasant sticky feeling on the skin. So I wonder if it is possible to wash it off after some time, without diminishing its efficacy.

  • Linda January 17, 2018, 2:52 pm

    Thanks so much for all the info and discussion. I am not a chemist obviously. In trying to either make my own products or fully understand the ingredients to buy my own vitamin c serum and other products, I have several questions please.

    1. I found a very pricey serum. It states only 7 ingredients in this order, water, ascorbyl glycoside, sodium hyaluronate, silk, sodium anisate, aspen bark extract and rosehip…in reading the above this product needs a stabilizer…what is the stabilizer from the list? I have tried to research each ingredient but I am not seeing one…am I not understanding?
    2. ..in any water based solution, if precautions are made to be sterile and the solution is stored in a dark, glass pump or spray bottle…how long before bacteria grows if no preservative is used?
    3. What do you know about Aspen Bark extract or phytocide aspen bark extract…can it be used as a broad preservative?
    I am looking for a safer preservative that is easy to use.
    Thanks for any feedback

  • g garay March 10, 2018, 8:59 am

    any thoughts on Avon Vitamin C product? the price seems right and Ascorbic Acid is listed high in ingredients and its say 10%

    • Perry Romanowski March 12, 2018, 2:20 pm

      Avon creates fine products but it would be surprising if it is used at 10%! It would certainly be worth trying to see if you get a benefit.

  • Amal March 17, 2018, 11:05 pm

    Hi Randy/ Perry,

    Thanks for the useful info. I’be been using L-ascorbic acid serum for many years with great result (Obagi) yet the oxidization is trouble some for most of the user; therefore, I would like to hear your thoughts on ethylated ascorbic acid, is it true to be a stabilized form of l-ascorbic acid? Is 30% concentration too high to be used during the daytime?
    Thank you very much, looking forward to your reply.

    • Illanit March 17, 2019, 8:27 pm

      Hi there, I would love to have an answer to Amal’s question. I was also using obagi L- absorbic acid 20% for quite some time and just switched to ethylated absorbic acid 30%. Are there any benefits in ethylated? Is 30% too high for daytime wear? Just trying to determine which vitamin c brand/ product is the best on the market? Thanks for your help!

      • Perry Romanowski June 15, 2019, 12:46 pm

        If you’ve tried something and it is working for you, then that is the best product. Most vitamin C products don’t actually work because they are not properly stabilized.

  • Emma April 8, 2018, 10:21 pm

    Hello, I know this is a very old blog post but still very relevant and I thank you for it.

    Question, what do you think about MAP combined with tretinoin in the same formulation? My Curology prescription contains MAP 5%, tretinoin 0.114% and Niacinamide 4%.

    I wonder if the MAP would be made more effective with tretinoin in the same formulation (I think hydroquinone combined with tretinoin is more effective than hydroquinone alone.)

    I’m dying to incorporate Vitamin C into my skincare routine, and have tried SAP and AA so far, both of which are ok for my skin (except for The Ordinary’s 23% Vitamin C & HA spheres, which literally gave me a chemical burn.) I just can’t decide whether to stick to AA or use a derivative. What do you think about alternating AA with MAP? One day AA, one day MAP, etc?

    Thank you so much!

    • Perry Romanowski April 16, 2018, 9:32 am

      This is the kind of thing where you have to experiment to see what works for your skin.

  • sylvia January 8, 2019, 6:22 pm

    Please help I know this blog is old but I really need advise on to different types of Vitamin C products….
    I’m looking at 2 products in powder form that I can mix and apply to my face…
    JUICE C Powder contains 100% L-ascorbic Acid $49.00
    HOLI C Powder contains calcium, organic sodium ascorbyl phosphate $169

    I’ve been advised that the JUICE C powder can only be mixed into face creams they sell and there vanilla and honey mask that you can leave on since its all natural, they’re not to be mixed with the serums or sunscreen products though.
    HOLI C can be mixed into anything, your serum, moisturiser, sunscreen of any brand.
    Which would be better because theres a huge price difference?
    I don’t think I’d feel comfortable mixing something into any brand since you don’t know what the concentrations of the products are.
    I was reluctant to buy the cheaper one as although I love their serums I don’t like there creams or the mask and can’t see myself mixing anything into it within their product range.

    • Perry Romanowski June 15, 2019, 12:51 pm

      I’d start with the cheaper one. But it’s unlikely you’ll see a benefit from using either product.

      • Sylvia February 22, 2020, 8:57 pm

        thank you

  • Josie March 5, 2019, 4:36 pm

    OMG it’s more than I can take in. I’ve kept your tab open as my definitive guide whilst trying to source a decent Vit C serum but am lost in the mire.

    Can you….for myself and other un-scientific and impatient people….. recommend a few Vit C products that are doing a decent job of it ?

    Thank you for your efforts…. it’s admirable!

  • Dawn June 11, 2019, 2:39 am

    How ph dependent are the derivatives? for example I see MAP and SAP in formulas with a ph of 5. Can they work at a low and slightly acidic ph?

  • Mary February 22, 2020, 9:02 pm

    My skin does not tolerate any product containing L ascorbic acid, this form makes my skin break out in acne. FYI my skin is normal and blemish free.
    So I’ve decided to go for a serum contains Magnesium Ascorbyl Phosphate (MAP). The concentration is at 20%. After one use my skin broke out in small pimples but not as bad as L ascorbic acid. So I decided to mix the vitamin C product with there antioxidant serum they sell. 2 drops of each reducing the % of MAP to 10%. By doing this my skin has tolerated it fine. The brand explained the reason for 20% MAP is because Vit C for collagen is effective at 10-15% absorption and because MAP doesn’t absorb as well as LAA the % is higher. However since my skin can’t tolerate that level and I’ve reduced in to 10% would that still be effective?

  • Helen August 8, 2020, 2:53 pm


    This is great because Vitamin C is listed as the 3rd ingredient. But the first ingredient is water. How do I tell whether or not the Vitamin C is going to dissolve quickly? How do I find out what the PH is?

    • Perry Romanowski August 12, 2020, 8:05 am

      You would need a pH meter to get the pH. But the ascorbic acid is unlikely to be potent in this product since it is water based.