≡ Menu

How can I tell if a product will cause acne? Episode 155

Can a patch test predict acne?

Janelly asks…I would like to know if patch testing a product for acne can really work. I see this concept mentioned a lot on Reditt as a way to test if a new skincare product will cause acne.14130436354_2488c613eb_b

That’s a great question but patch testing for acne does NOT work. Unlike an allergic reaction (where can occur in minutes or hours) the process of acne genesis takes much longer.

According to Fisher’s Contact Dermatitis, acne can result from topical application of cosmetic products via two mechanisms. The first is referred to as a “true comedone” process and that takes several months to develop. The second is the result of follicular irritation and that takes weeks to occur.

A patch test that involves leaving a product on your skin for only a few hours or even a few days will not accurately predict whether or not you will break out.

Even if you could patch test and leave it on, or reapply it, I’m not sure I’d trust the result because it could be a false negative based on the small area of skin which you applied it to.
She said applying it all over her check for several weeks but at some point that’s not a patch test that’s just using the product.

We shared this response with Janelly via email and she asked this follow up question: “Now that I know that it takes at least several weeks to a few months to know if product is breaking me out, is there a way of isolating which product is breaking you out? Is this even possible?

Trying to isolate which product is breaking you out is not very practical because you can’t really do long term single variable tests on yourself very well. I don’t think anyone is really going to put a single product on their face and leave it there for several weeks/months without washing face, wearing any makeup, putting on sunscreen, etc.

And you have to repeat that process for every product you want to evaluate. Even IF you did all that you still can’t really control for other factors like hormonal changes and changes in diet.

About the best you can do is buy products that are labeled as “non-comedogenic.” Even that is no guarantee because the testing that’s done to evaluate whether or not a product will give you acne is NOT very definitive.

We’re talking about the rabbit ear assay. In fact, there are some people who say that test is not predictive AT all. So at best it can give you some guidance.

The bottom line is that predicting acne is VERY difficult and don’t waste your time on patch testing.


Can shampoo and conditioner be concentrated?

Scott says…I use a shampoo and conditioner by Pureology and on the front of the bottles they claim the products are concentrated formulas. Do you know if this is true or not? Is it possible to formulate shampoos and conditioners in a way that makes them more concentrated?

A claim like that is meaningless because it doesn’t provide a comparison to anything else. More concentrated than what?? And even if it is true, what’s the benefit? Do they claim that it works any better? And again, better than what?

Now, I can think of a couple of applications where this MIGHT make sense. The first is in the case of deep cleansing products where a slightly higher surfactant load is justified. (Although most shampoos have plenty of cleansing power.)

The second is It MIGHT make sense from a sustainability point of view – you make the product more concentrated so you get more uses per bottle which reduces packaging waste. I’ve seen this used successfully in dishwashing soaps and laundry detergents.

But you have to realize that there are some negatives associated with increasing concentration. Hair care products have to have the right aesthetics or they don’t feel right on your hair – it’s tough to make a highly concentrated product that isn’t hard to disperse through your hair.

And some ingredients just don’t work well at have a higher concentration. For example Polyquat 7, which is a great condition agent used in shampoos, can build up on hair if you use to much and it can make the product very stringy and pituitous. “Consisting of, or resembling, mucus.”

In most cases, when a company tells you their shampoo or conditioner is “more concentrated” it’s probably just a marketing gimmick. The bottom line is that the claim could be true but rather pointless.

Is Nugene Worth the money?

Lee asks… I need to know if NuGene Universal Serum is worth the astronomical price of $300 a bottle!! Is there comparable products for less money?

This is a product based on stem cell media. We’ve talked about stem cells before and science says that they don’t work when applied from topical products. (in fact here’s a recent article on that very topic: http://www.miamiherald.com/living/health-fitness/skin-deep/article62053467.html)

The product also contains 4 different peptides. Peptides are promising ingredients that do have some data which indicate they have anti-aging properties including collagen stimulation and slowing the breakdown of the structure of skin. But there are plenty of cheaper peptide products on the market. To be honest, I didn’t have time to track any down but you can Google products that have these ingredients and you’ll find cheaper versions.

Their website includes links to clinical studies in which their product(s) were tested (single blind, half face test) against nothing. The results showed their products moisturize, reduce fine lines and wrinkles, etc, better than no treatment at all.

Most anti-aging products will produce similar results so I don’t see anything compelling that shows this product is worth $300. They did have one study showing gene expression but this was done in vitro (on cells in the lab) so it doesn’t necessarily translate to real life. I say save your money.

Ingredients: Human Adipose Derived Stem Cell Conditioned Media, Palmitoyl Tripeptide-5 / Glycerin, Acetyl Hexapeptide-8, Polysosbate-20, Acetyl Tetrapeptide-5, Aloe barbadensis Leaf Juice , Pentapeptide-18 / Caprylyl Glycol, Nano Chloropsis oculata Extract / Pullulan, Citrus grandis Seed Extract, Sodium Carboxymethyl Cellulose, Phenoxyethanol / Sorbic Acid / Caprylyl Glycol, Sodium Hyaluronate, Fragrance, DL-Panthenol, Niacinamide, Camellia sinensis Leaf Extract, Nanosome Copper Peptides, Human Oligopeptide-1

Beauty Science News

Perfume can influence your dreams


Here’s an interesting article I stumbled on which discusses work that researchers did looking at the influence that smell has on your dreams. According to scientists at the University Hospital Mannheim in Germany, people who were exposed to the scent of rotten eggs during sleep had unpleasant dreams while people exposed to the scent of roses had pleasant dreams.

In this study of 15 women…oh brother, researchers hooked them up with tubes taped to their nostrils and had them go to sleep. They monitored the subjects’ brain activity. When they hit the REM stage they gave them a shot of either rotten egg smell, rose smell, or no smell for 10 seconds.

The scientists then let them sleep for another minute and woke them up. They asked them to describe their dreams at that moment and rate the experience as positive or negative. It turns out that people who had the rotten egg smell dreamed negatively while those with the rose dreamed positively.

They think that this could be a potential treatment for nightmares or other sleep disorders. I’m thinking this might be a whole new product category for fragrance makers.

UPF: The SPF of clothing


We talk a lot about sunscreen products on the program but I hadn’t given much thought to the sun protection factor of clothing. Fortunately, our friend Nikki at FUtureDerm has. She published an interesting article about sun protection from clothing which is called UPF or Ultra Protection Factor. Here are a few key points:

Dark protects better than light fabrics.
Heavier fabrics are better than lighter fabrics
Tighter weaves are better than looser weaves and knits
Synthetic is better than natural fabric (e.g. cotton)

If you’re interested, you can look up the ratings for different fabrics. There’s a rating scale published by ARPANSA which stands for Australian Radiation Protection and Nuclear Safety Agency.

Perfumes pollution in the canals of Venice


You ever wonder what happens to the fragrances used in soaps, shampoos and skin lotions? Well, according to this study they end up in our water supplies and can persist for a long time. That is if you live in a place like Venice where there are no sewers.

Between April and December 2015, scientists repeatedly collected water samples from 22 places between the inner canals in the historic center of Venice, the island of Burano and at two points in the far-north lagoon. They were looking for the presence of 17 fragrances among the most used and chemically stable between the thousands available to the cosmetics industry.

Traces of ‘scented’ molecules have been identified in all sampling sites, including those more distant from inhabited areas, though illustrating concentrations up to 500 times higher in the inner city canals. Samples collected during conditions of low tide in Venice and Burano showed concentrations comparable to those of untreated waste water.

Of course, they don’t know the consequences of this build-up of fragrance molecules and they aren’t at levels that would be toxic to marine organisms.

So what does it all mean? I don’t know. It seems like these scientists were looking for some way to convince people that there might be a problem and that they need more money to study it. It seems like there is a lot of research like that.

New mascara will make you more popular


A recent article from Cosmetics Design discusses a Japan based company that is developing what they call “an aesthetic shape-controlling mascara” that will give you “enhanced social impression in Asia.”

I’m not sure I totally understand this but the company, Kosé, says that their studies show that women who wear mascara has higher self esteem and social status and they link that to curve of their eyelashes because it makes the eye appear bigger and more open. So, they developed a mascara specifically to enhance this eyelash curl. It uses water based resins like you’d find in hairsprays to control the lash shape. That’s an interesting trend based on Asian culture, I wonder if it will ever make its way here. (Cheap Trick Big Eyes)

New sunscreen applicator


Putting on sunscreens is a pain in the ass. And this is why people don’t do it more. I know I don’t like to. And the spray sunscreens seem like such a waste to me.

Well, here’s a new packaging design that might change that. It’s called the BlokRok and it reminds me of an antiperspirant stick. You put your sunscreen in the container and then roll it on your skin. No mess and you get the proper amount in the right places. We’ll see if this takes off.

iTunes reviews

Shinobuchin from Australia says…Very informative and brilliant show! — 5 stars. Randy and Perry are like my besties when it comes to beauty, trust them and nothing else any packaging or fancy ad campaign will ever tell you.

Blondenicky says…Educates While Entertains — 5 stars. This show has taught valuable lessons, for example, It’s Ok to Have Lead In Your Lipstick, and has answered Other Beauty Questions I’ve Been Dying to Know 😉 What started out as a way to keep my entertained at work has also given more insight into the cosmetics I use. I’ll never walk into a store the same way again.

{ 7 comments… add one }

  • L. Pazzaglia October 18, 2016, 6:44 am

    In terms of predicting whether a product will cause acne, why not just run the ingredient list through the COSDNA website, they list the “comedogenic” factor of each ingredient. Just copy and paste the ingredient list here and click “Analysis”:

    Randy and Perry, wouldn’t the comedogenic factor of the product ingredients be a good predictor as to whether the product could cause acne?

    I don’t really know how the comedogenic scale was created – so it might based on those rabbit ear assay’s that aren’t very predictive at all.

    What do you think?

    So far the acne ratings in from COSDNA have been an accurate predictor of acne for me!



    • Randy Schueller October 18, 2016, 8:23 am

      This data base certainly can be helpful but it has limitations. First of all, there’s no perfect screening tool for comedogenicity so what ever it’s based on won’t be totally accurate. Second, and more important, it only looks at the effect of single ingredients. When ingredients are blended together one ingredient may affect the commedogencity of the other. That’s why finished formulas have to be assessed not just their components.

  • Grace October 18, 2016, 9:58 am

    Hi guys! Interesting and informative as usual. and especially, thanks for the info on sunscreen in fabric and potential easier application! Now that I live on the coast in Southeast Georgia, I go to the beach daily and sunscreen is a pain. And of course, anything other than shorts/T-shirts are too warm except maybe a few days in December-January!

  • Rachael October 19, 2016, 9:47 pm

    Your blog remains my favorite and one I’m always telling friends about. Thanks for the science based info! And for saving me so much cash!

    Question for you: I just picked up a new sensitive toothpaste and it has an ingredient I’ve never seen before in toothpaste – arginine. I’ve seen this many times in hair products. Can you give us the scoop on this? Is it legit? The box claims this works better than conventional fluoride based products. I only get sensitive teeth like once a year and usually buy the Kirkland brand toothpaste, but this was on sale…


  • Eileen October 20, 2016, 12:38 pm

    You Brains really are the best–so much great information in an entertaining format. And, thank you for the links 🙂

    Being a So Cal gal, I get lots of sun exposure. Our weather is heaven sent and that means light-weight, casual clothing most of the year. I don’t have any issue with daily sunscreen application because the products I use are “cosmetically elegant”. By that I mean they apply easily, are transparent when spread out, and feel comfortable on the skin. (Jack Black Sun Guard SPF 45 for body and TIZO2 SPF 40 for face) However, when I’m outside working with the horses or doing major gardening, I get sweaty, dusty, and dirty. That makes reapplying my usual sunscreen products a terrible mess and so I bought a long-sleeve sunscreen tunic and wide brimmed sunscreen hat. Those have proven to be the perfect solution.

  • Kalpana Sharma October 23, 2016, 4:11 am

    This is my first visit to this blog and I loved it. This is full of knowledge and Tips. I found so valuable information here. This blog has saved in my favourite list now. Thanks for sharing great info. Keep it up!

Leave a Comment