≡ Menu

Is bar soap bad for hair?

Kviskas says…Hello, my question is: Can I use a piece of ordinary toilet soap instead of a shampoo? Some say it’s really harmful, others say something like “My grandma has been using it all her life and still has wonderful hair.” When I tried it I loved the volume it gave my blond thin hair (after soap I also used a conditioner), so I’d love to use it all the time, but afraid that it can make my hair dry and fragile. 

The Beauty Brains respond: 

You CAN use bar soap on your hair but it’s certainly not the best option. Here’s why:

Soap lacks conditioning agents

Even the best modern soap bar is not very good at depositing conditioning agents on here.  Most shampoos (except perhaps the clarifying varieties) contain some level of conditioning agents which help detangle hair and prevent snagging which can cause damage and breakage. This is less of an issue if you’re following up with a separate conditioner but it’s still something to be aware of.

Soap causes scummy build up

This is less of a problem than it used to be but if you have hard water and you use regular bar soap you may experience a build up of soap scum on your hair. (This is sometimes referred to as “bathtub ring.”) It occurs because the mineral ions in hard water displace the sodium ions from the soap which results in an insoluble gunk that won’t rinse away very easily.

Regular soap is not good for skin

Classic soap (we’re not talking about synthetic detergent bars here) has a high pH which is problematic for skin. The high pH of soap increase the amount of time required for the skin’s acid mantle to restore itself. That means your skin is more prone to dryness and infections.

The Beauty Brains bottom line

Occasional use of bar soap as shampoo is perfectly fine. However, if you make it a daily practice you’re likely to find that your hair is in worse condition than if you used a traditional shampoo.


Is your shower sponge making you sick?

LindyGirl asks…How often should you replace your shower pouf? Is the ‘once a month’ rule of thumb genuine or a marketing ploy?

The Beauty Brains respond:

When providing a rigorous scientific answer to a question such as this I think the most important first step is to come up  a good title. Before settling on “Is your shower sponge making you sick?” I had also considered the following titles:

  • Bacteria in your bath.
  • What’s lurking on your loofah?
  • Perilous pathogens on your pouf!

I hope you enjoyed this little peek behind the Beauty Brains curtain  - now on with the answer!

Shower poufs and pathogens

According to Journal of Clinical Microbiology, changing your pouf only once a month may not be often enough! That’s because poufs, sponges, and loofahs can harbor various strains of pathogenic bacteria. Specifically, researchers found gram-negative (Pseudomonas, Xanthomonas, and Klebsiella) as well as gram-positive (Enterococcus and group B Streptococcus) species. (To be clear, this study was done on loofahs which are cellulosic in nature. But the plastic-like material of poufs and synthetic sponges have also been shown to support bio-film growth.)

Clean and dry

That doesn’t necessarily mean you need to buy a new cleaning aid. You could clean the old one, if you do it properly. The study authors recommend soaking your loofah in 10% solution of hypochlorite (bleach). Unfortunately, the regular bleach you buy in the store only contains about 3 to 8% Sodium hypochlorite and that’s when it’s fresh. If you have and old jug of bleach that’s been sitting around your house the active content could be even less. Still, it can’t HURT to use a weaker bleach  solution to disinfect, you’re just less likely to completely kill everything. But, its certainly better than doing nothing.

By the way, in case you think you’re being clever by letting your sponge thoroughly dry out in the hopes that  lack of moisture will prevent bacterial growth, think again. According to the paper it takes almost 2 weeks of drying to kill off the microbes. I may be frugal but skipping showering for two weeks is not worth saving the cost of a new sponge.


Can skin cleansers really deliver vitamins and other anti-aging ingredients or is that all hype? We explain it all. Plus: In Beauty Science News we cover the case of the Fashion Billionaire and the Fountain of Youth.  Wow! 

Click below to play Episode 25 or click “download” to save the MP3 file to your computer.

Show notes

Beauty Science News: The Case of the Fashion Billionaire and the Fountain of Youth

70 year old Fashion Designer Peter Nygard says stem cell treatments are making him younger.

Question of the week: Can skin cleansers deliver active ingredients?

Cindy asks: Can facial cleansers deliver active ingredients like AHAs and vitamin C?

Let’s start by looking at what methods can be used to deposit ingredients from a rinse off product.

Coacervation and dilution deposition

The ingredient has limited solubility in water- as the product as diluted during rinsing the product “falls out” of solution and stays on the skin.


Involves the use of a shell or vesicle which serves 3 purposes:

1. Suspends the active in the delivery medium
2. Shields the active from interaction with other ingredients
3. Deposits the active on substrate in such a way that it remains after rinsing.

A thorough discussion of all the different types of encapsulation is beyond the scope of this show but in rinse off systems phospholipids, polymers, and even silicones can be used as encapsulates.

Can you tell if a product will deposit actives by reading the ingredients?
Unfortunately, either of these methods are tough to spot just from ingredients. That’s because the ingredients which are responsible for deposition are typically multifunctional and can serve other purposes in the formula.

For example, the same surfactants used in coacervation are used to clean and provide lather. The same polymers that can encapsulate actives are used to thicken. In addition not every delivery system works for every ingredient. Phospholipid encapsulates can’t deliver water loving materials like Vitamin C. The best you can do is look for a reputable brand which gives some indication of how it works.

Here are some ingredients that are proven to be deliverable from skin cleansers.

According to this paper it is possible to deliver sal acid to skin from cleansers with acrylate polymers. We also found another study published by company shows increased deposition/adhesion of sal acid when encapsulated which makes sense. And we’ve also seen similar evidence for other acne drugs like 5% Benzoyl Peroxide In a cleanser and 2% resorcinol.

We know that fluoride can be delivered from a cleanser, namely toothpaste. This is thought to work because Fl more easily sticks to the enamel that has been attacked by acid producing bacteria. So it’s a type of charge deposition.

You’ll see a lot of anti aging actives in cleansers, like vitamins, like C, E, and niacinamide, hyaluronic acid, However, there’s little evidence that these will deposit. One exception that we’ve seen with data to back it up is vitamin C which can be delivered from a silicone vesicles that’s based on PEG-12 Dimethicone.

Dandruff shampoo are over the counter drugs which are proven to work so we know that actives like Coal tar, ketaconazole, sal acid, selenium sulfide, zinc pyrithione will deposit from a rinse off system. Keep in mind that the conditions required to deposit on hair are not necessarily the same as those for depositing on skin.

There are antibacterial wash products but those don’t necessarily have to remain behind after rinsing because they can kill bacteria on contact. On the other hand, antimicrobials like benzalkonium chloride could deposit by charge.

Moisturizing oils
Oils are relatively easy to deposit on skin by using surfactants bilayers, polymers, nonionic capsules and so forth. For example, P&G has patented technology to deliver petrolatum from a body wash and we’ve seen studies showing that plant oils such as jojoba, sunflower, and soybean can be delivered as well.

UV absorbers
Finally, believe it or not, you can even deliver UV absorbers from a facial cleanser or body wash. Aquea Scientific has a patent on this technology and it can be found in the Freeze 24/7 line. It really works but has limitations. It works by encapsulating the sunscreen and incorporating a cationic polymer to create some charge deposition.

So know you know HOW actives are delivered from cleansers and you have an idea of which actives really work, let’s talk about why you’d want to get your actives from a cleanser rather than a leave on product like a cream or lotion because there are advantages and disadvantages to this approach.

Advantages of using a cleanser to deliver actives
If you really can deliver actives from a cleanser there are several advantages.

  • Improve convenience. For example, you can eliminate a step by applying sunscreen while you wash your face.
  • Enhance functionality, you can boost the benefit by combining with a cleansing step for example, if you’re scrubbing your face to exfoliate it, you can exfoliate even better by including an AHA in the cleanser.
  • Eliminate a negative. For example, you can deliver dandruff actives from a conditioner but some people, especially guys, think that conditioners may leave junk on their scalp that makes the problem even worse. Delivering the actives from a shampoo solves that problem.

Disadvantages of using a cleanser to deliver actives
However, things aren’t always that simple and there are some serious issues with this approach.

  • Reduces performance. Anytime you’re striving for 2 in1 approach you’re going to compromise efficacy.
  • Makes it harder for you to pick products that really work. It’s hard to spot a cleanser that will really deliver what it says. You have to really scrutinize a cleanser that will deliver SPF it’s kind of a no brainier with a leave on product.
  • Increases product cost to more expensive products: If you want to deliver 2% acid from a cream you put in 2% if you want to deliver 2% from a cleanser you may have to put in 5% AND/OR you may have to have expensive delivery system like encapsulation. And you STILL won’t deliver an optimum dose. So why pay more for a product that does less?

The Beauty Brains bottom line

Cleansers can deliver active ingredients but there will certainly be a trade off in performance. You have to ask yourself WHY you would choose delivery from a cleanser rather than a leave on product to make the best choice.

LIL buy it now button

Buy your copy of It’s OK to Have Lead in Your Lipstick to learn more about:

  • Clever lies that the beauty companies tell you.
  • The straight scoop of which beauty myths are true and which are just urban legends.
  • Which ingredients are really scary and which ones are just scaremongering by the media to incite an irrational fear of chemicals.
  • How to tell the difference between the products that are really green and the ones that are just trying to get more of your hard earned money by labeling them “natural” or “organic.

Click here for all the The Beauty Brains podcasts.


Can you make your own Tend Skin ingrown hair treatment?

Rozy asks…Can you make your own Tend Skin ingrown hair treatment?

The Beauty Brains respond:

The answer is sort of…kind of…maybe…a little bit.

Rascally Rozy’s question was prompted by this video  which shows you how to make your own Tend Skin by crushing aspirin tablets and mixing them into isopropyl alcohol and witch hazel. Unfortunately, it’s not as easy as Lacey makes it appear.

What is Tend Skin and how does it work?

Tend Skin, as most ingrown hair products, uses either acetylsalicylic acid (aka aspirin) or salicylic acid to unblock the follicle by removing dead skin cells and to provide an anti-inflammatory effect. Tend Skin is a patented formula which optimizes the effect of the acetylsalicylic acid (let’s just call it ASA, ok?) by combining it with specific ratios of alcohol and polyols such as glycerin and propylene glycol. According to the patent, polyols like these are critical to proper product performance. The patent also notes that the “most effective and soothing” concentration of ASA is about 15 percent. Here, then, are the Tend Skin Ingredients along with the function of each one:

  • Acetylsalicylic Acid – active ingredient that unblocks pores and soothes skin
  • Isopropyl Alcohol – solvent
  • Butylene Glycol, Glycerin, Diglycerin – polyols that help deliver the ASA and provide good skin feel.
  • Cyclomethicone – spreading agent
  • Polysorbate 80 – coupling agent

Can you really make your own Tend Skin?

Lacey’s recipe calls for 9 tablets of aspirin mixed into Isopropyl Alcohol (IPA) and another 4 tablets mixed into Witch Hazel for a total of 13 tablets. Each tablet contains 325 mg of the active ingredient, Acetylsalicylic Acid, and the rest is starch which is an excipient or carrier. That means 1/2 cup of her recipe contains about 4.5% ASA. As we noted above, the optimal concentration of ASA is about 15%. So Lacey’s recipe is only about 1/3 as powerful as the product she’s trying to copy.

Couldn’t she just triple the number of aspirin tablets? It’s not that easy because there’s a solubility issue. She’s using over the counter IPA which is only 70% alcohol; the rest is water which is not a good solvent ASA. So her mixture is leaving some of the ASA undissolved. Also, all that starch she’s adding won’t dissolve in alcohol so it makes a white sludgy mess. (She even says in the video that you have to shake the product every time because it settles out.)

So there are three basic problem with this DIY Tend Skin:

1. The active ingredient concentration is too low.
2. It lacks polyols which help optimize the deliver of the active.
3. It’s gunked up with starch which makes it impossible to tell if the active ingredient is properly dissolved.

The Beauty Brains bottom line

While you can attempt to make your own solution of acetylsalicylic acid it’s difficult to optimize it to give you the best effect of treating ingrown hairs. You may save some money but you’ll also lose some efficacy. There are other ingrown hair products on the market that use the same basic technology that are much less expensive than Tend Skin. Using one of those is likely to give you better results than trying to make your own.


Beauty Science News – April 6

More scoops from the seamy underbelly of the world of beauty science…



Penetrex cream – Look at the label

Penetrex is a top-selling health and beauty product on Amazon. How does it reduce painful inflammation? Let’s look at the label.

Apparently this is another one of those companies that doesn’t like to share product information because I couldn’t I can’t find a complete ingredient list anywhere.  So, here are the active ingredients listed on their website:

  • Vitamin B6
  • Arnica
  • MSM
  • Cetyl Myristoleate
  • Shea Butter
  • Boswellia Serrata

Penetrex claims

  • Penetrex represents a revolutionary breakthrough in the treatment of inflammation related ailments including: Carpal Tunnel Syndrome , Tennis Elbow,  Golfer’s Elbow, Tendonitis, Bursitis, Arthritis, Plantar Fasciitis.
  • Utilizing an innovative topical process, Penetrex delivers …deep into muscles, nerves, ligaments & tendons.
  • Researched & developed by a renowned Chemist in Southern California, Penetrex is available without a prescription.

How does Penetrex work?

This one is a puzzle to me since, as far as I can tell, it doesn’t contain any of the approved over-the-counter drug actives for inflammation. The website provides a breakdown of what each ingredient does but unfortunately this information seems to be more anecdotal in nature than anything else. What I mean by that is they claim these ingredients are known to work yet they don’t cite any specific studies proving the point. The only example of a clinical study which is cited is in regards to Cetyl Myristoleate. However this particular study was done on oral dosage with the patients also using topical treatment “according to their perceived need.”  If they tested a combination of the orally ingested compound along with the topical treatment there’s no way to tell if the topical treatment alone is effective!

The Beauty Brains bottom line

I don’t see anything to demonstrate that this product would really be effective but they do offer a money back guarantee. I suppose if you want to buy some of this you can always return it but let the buyer beware!  By the way, if anyone from Penetrex happens to read this and you have any additional information on how your product works, we’d be happy to publish it.


Is fabric softener a good hair conditioner?

Ling loves to learn…I was reading this post about replacing hair conditioner with fabric softener. The blogger’s mother found this “idea” through Woman’s World magazine.  This sounds really dangerous….. Could the magazine be sued for liability issues? But most importantly, is this a bad idea?

The Beauty Brains respond: 

It amazes me that people are scared to death of the so called “toxic ingredients” in cosmetics (which are designed to be used on skin) but they have no problem applying a household laundry product to their body (which is NOT designed to be used directly on hair and skin.) There are two main reasons why this is a bad idea:

Putting laundry products directly on your skin is not safe

Despite what  people may tell you, cosmetics ARE regulated to ensure they are safe.  These products are  formulated and tested to ensure they are safe for direct, prolonged contact with skin. Not surprisingly the laws that govern fabric softeners are different than the ones that control cosmetics. That’s not to say that fabric softeners are necessarily dangerous but they contain ingredients that aren’t designed to be directly applied to skin. Here are three examples:

  • The conditioning ingredients themselves may be more aggressive and therefore more irritating.
  • The colorants don’t have to be approved for use in cosmetics and therefore may be unsafe.
  • The co-solvents used (which would be rinsed away in the laundry process) may dry skin or have other undesirable side effects.

Fabric softener won’t work as well as conditioner

Even if safety wasn’t an issue, why would you want to do this? Fabric softeners are formulated to soften fabric where as hair conditioners are designed to detangle, smooth, and increase shine. The two products are similar but that doesn’t mean they are interchangeable. Here are a few examples of characteristics that you want from a conditioner that a fabric softener is NOT optimized to deliver.  

  • Nice hair feel: Fabric softening ingredients have a stronger charge than many hair conditioners so they may stick to fabric to provide long-lasting softness. This is a good thing when it comes to your clothes which you wash rather infrequently. However in the case of your hair, repeated frequent use of fabric softer could result in horrific buildup. Also, the types of quats (quaternary ammonium compounds) used in hair conditioners are fine-tuned to deliver the best aesthetic experience possible. The ingredients that are good at softening fabric may leave hair feeling heavy and limp with a notable waxy coating.
  • Increased shine: A good conditioner will include some sort of agent to add shine to your hair, for example a silicone. You will not find this in a fabric softener since “shine” is typically not desirable of clothing.
  • Pleasant scent: Fabric softeners are heavily fragranced you may find yourself choking on the scent of Downey or Snuggle compared to your typical hair care product.

The Beauty Brains bottom line

While fabric softener may function as a hair conditioner why would you bother when you’re risking excessive buildup, poor performance, and skin irritation or worse? As we noted in our recent post about using lip gloss as eye shadow, there’s a lot of bad beauty advice out there. Fortunately the Muse was savvy enough to NOT recommend using this do-it-yourself product.


The dangerous truth about using lip gloss as eye shadow

Why do some beauty websites give irresponsible and dangerous information?

As our regular readers may know, I have a kind of love-hate relationship with the website Refinery29. I love it because they have the really good at ferreting out interesting news stories on beauty and fashion. I hate it because, on occasion, I have seen them provide information that is… dubious… at best. 

Case in point is this article about using lip gloss to achieve a wet look eye shadow.  The author of the article discusses a video by makeup artist James Vincent who uses lip gloss to achieve that wet look. While some lip products MAY (and I stress MAY) be okay to use around the eye, others are most certainly not. One reason is that the eyes are particularly sensitive and an ingredient, such as a flavor,  maybe perfectly fine on the lips but could irritate the hell out of your eyes. Another potentially more serious problem is that the colorants used in lip products are not necessarily approved for use around the eyes.

Not all cosmetic  colors can be used near eyes

To keep us all safe, colorants for cosmetics are controlled by the FDA. Certain colors are NOT allowed to be used close to the eye because they can cause problems (including blindness!) Here are the colors used in the Ardency lip gloss referenced in the video:

Titanium Dioxide, Red 28 Lake, Red 6, Red 7 Lake.

And here’s what the FDA says about applying these red colors to the area of the eye:

“None of these colors may be used in products that are for use in the area of the eye unless otherwise indicated.”

Missed opportunity

I shared this information in a comment on the post and suggested that the author include a disclaimer so no one is accidentally harmed by following their advice. In a response to my comment the moderator at Refinery29 acknowledged they were wrong in response and they changed the headline of the post from “Lip Gloss On Your Lids? Yes, Really”  to “Wet-Look Lids? Yes, Really.” However, as far as I can tell they didn’t change any of the text of the article and they certainly didn’t change the video itself. In other words they’re still giving out the same dangerous advice which you won’t realize is problematic unless you scroll all the way down to the comments section.

Shame on Refinery29 for not taking this opportunity to better educate their readers. And even more shame on this expert make up artist who should know better.

Have you ever seen dangerousness information on a beauty website? Leave a comment and share your thoughts with the rest of the Beauty Brains community.


Does exfoliation make you run out of skin faster? Plus:  Beauty Science or Bull Sh*t Round 2: Randy quizzes my beauty science knowledge again. 

Click below to play Episode 24 or click “download” to save the MP3 file to your computer.

Show notes

Beauty Science or Bull Sh*t

This is the game where Randy gives me 3 beauty science news stories and I have to tell the real from the fake. You can play along at home – just hit the pause button before we give the answer. Here are this week’s headlines, can you tell which one is TRUE?

1. Bacteria-filled liquid crystals could supplement the skin’s natural defense system.
2. Shampoo ads that ask you to imagine the smell of the product are more compelling.
3. Beautiful people have fewer pathogenic nasal bacteria.

Question of the week: Does exfoliating make you run out of skin?

Melanie asks…”I’ve read that there is a limited number of times a person should exfoliate due to the Hayflick limit.  Is that true?”

What is exfoliation?

Exfoliation is the process of removing excess dead cells which causes your skin to increase production of new cells. This is technically known as “increasing cell turnover.” Benefits of exfoliation include facial rejuvenation, acne control or prevention of precancerous growths.

Methods of exfoliation

  • “Regular” face washing
  • AHAs
  • Retinoids
  • Chemical peels (glycol acid, TCA)
  • Dermabrasion

What is the Hayflick limit?

It’s a property of cells discovered by Leonard Hayflick in 1961. He found that there is a limit to the number of times a fully differentiated human cell divides. These cells can only divide about 50 times and then they die. This happens because when cells replicate they lose a little piece from the end of their DNA chain, which is called a telomere. Eventually the telomere becomes so short the cell can no longer reproduce. So does this mean that exfoliating causes our new cells to be used up faster? Will we eventually run out of skin? The answer lies in the TYPE of cell.

Two types of cells

Stem cells are undifferentiated (or unspecialized) cells which means they can reproduce in two ways: they can make more stem cells or they can differentiated cells. (Potential future form)
Differentiated cells change size, shape, and metabolism to perform a specialized task. (Final, useful form)

Which type are skin cells?

Actually they’re both. The deepest layer of the epidermis is called the stratum basale which consists of basal keratinocyte cells. These are epidermal stem cells. They divide to form two types of cells: keratinocytes (which are “regular” skin cells) or more stem cells.

The keratinocytes die and are sloughed off and are replaced by new cells about every 35 days. So in other words, your skin is replaced about 10 times per year.

So why don’t we run out of skin cells?

The Hayflick limit only applies to fully differentiated cells. (In this case the keratinocytes.) Stem cells are NOT fully differentiated so they can continue to reproduce without any limit.

Here’s common sense proof: If the Hayflick limit applied then…

  • ANYTHING that scrapes of skin would use up your cells (not just exfoliating): Taking a bath, shaving your face – or your legs – or whatever you shave.
  • Skin scratches and cuts would stop healing at some point.
  • Criminals could just sand away their finger prints and they wouldn’t grow back.

None of these things happen because the Hayflick limit doesn’t apply to epidermal stem cells.

The Beauty Brains bottom line

The Hayflick limit doesn’t apply to the type of cells that make new skin cells. So you can never run out of skin by exfoliating. In fact, exfoliating provides health and beauty benefits so it’s something that you should do regularly.

LIL buy it now button

Buy your copy of It’s OK to Have Lead in Your Lipstick to learn more about:

  • Clever lies that the beauty companies tell you.
  • The straight scoop of which beauty myths are true and which are just urban legends.
  • Which ingredients are really scary and which ones are just scaremongering by the media to incite an irrational fear of chemicals.
  • How to tell the difference between the products that are really green and the ones that are just trying to get more of your hard earned money by labeling them “natural” or “organic.

Click here for all the The Beauty Brains podcasts.


Did you see the news story last month about the Meth Lab guy who was busted while wearing a Breaking Bad shirt? As funny as that is, it turns out that methamphetamine production has a not so amusing consequence for consumers of beauty products.

Why is the FDA is “Breaking Bad” on silicones?

According to an FDA press release, the criminal chemists who run Meth labs are increasingly using silicones, especially dimethicone, as a source material for methamphetamine. In the past the FDA has limited access to other source materials, like the over-the-counter decongestant pseudoephedrine, but now the savvy sinister scientists of the drug world have figured out how to extract the components they need from common hair and skin care products.

Dimethicone is frequently used in beauty products because it’s an excellent skin protectant and provides slip and shine for hair. In fact, it’s unusual to find a high quality skin moisturizer or hair conditioner that does NOT include some form of silicone so the loss of this ingredient is expected to significantly impact consumers.

According to the FDA the silicone ban will take effect “as soon as it can be phased in” which does not give cosmetic product manufacturers much time to find suitable replacements.

You can click here to read the details from the FDA’s press release as well as the Personal Care Product Council’s response.