Follow us on our new Insta page »
Peter Thomas Roth Glycolic Acid 10% Moisturizer

Peter Thomas Roth
Glycolic Acid 10% Moisturizer

A gentle exfoliating moisturiser for dull, lacklustre skin.
Uploaded by: melioraspero on 28/06/2018

Peter Thomas Roth Glycolic Acid 10% Moisturizer
Ingredients explained

Also-called: Aqua;Water | What-it-does: solvent

Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product. 

It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water. 

Expand to read more

Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying. 

One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time. 

Glycolic Acid - superstar
What-it-does: exfoliant
  • It’s the most researched AHA with the most proven skin benefits
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It can help skin’s own collagen production that results in firmer, younger skin
  • It can fade brown spots caused by sun damage or PIH
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
  • Slight stinging or burning with a stronger AHA product is normal
  • If your skin is very sensitive, rosacea prone choose rather a BHA or PHA product
Read all the geeky details about Glycolic Acid here >>

Glycerin - superstar
Also-called: Glycerol | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
  • A natural moisturizer that’s also in our skin
  • A super common, safe, effective and cheap molecule used for more than 50 years
  • Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
  • Effective from as low as 3% with even more benefits at higher concentrations up to 20-40% (around 10% is a good usability-effectiveness sweet spot)
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

Also-called: Aloe Vera | What-it-does: soothing, moisturizer/humectant

Aloe Vera is one of today’s magic plants. It does have some very nice properties indeed, though famous dermatologist Leslie Baumann warns us in her book that most of the evidence is anecdotal and the plant might be a bit overhyped.

What research does confirm about Aloe is that it’s a great moisturizer and has several anti-inflammatory (among others contains salicylates, polysaccharides, magnesium lactate and C-glucosyl chromone) as well as some antibacterial components. It also helps wound healing and skin regeneration in general. All in all definitely a goodie. 

What-it-does: moisturizer/humectant, solvent | Irritancy: 0 | Comedogenicity: 1

Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.  

BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.

Expand to read more

It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive. 

What-it-does: emollient

A super common emollient that makes your skin feel nice and smooth. It comes from coconut oil and glycerin, it’s light-textured, clear, odorless and non-greasy. It’s a nice ingredient that just feels good on the skin, and it’s also easy to formulate with. No wonder it’s popular. 

What-it-does: emollient, emulsifying | Irritancy: 0 | Comedogenicity: 1-2

A super common, waxy, white, solid stuff that helps water and oil to mix together, gives body to creams and leaves the skin feeling soft and smooth.

Chemically speaking, it is the attachment of a glycerin molecule to the fatty acid called stearic acid. It can be produced from most vegetable oils (in oils three fatty acid molecules are attached to glycerin instead of just one like here) in a pretty simple, "green" process that is similar to soap making. It's readily biodegradable.

Expand to read more

It also occurs naturally in our body and is used as a food additive. As cosmetic chemist Colins writes it, "its safety really is beyond any doubt".

What-it-does: surfactant/cleansing, emulsifying | Irritancy: 0 | Comedogenicity: 0

A very common water-loving surfactant and emulsifier that helps to keep water and oil mixed nicely together. 

It's often paired with glyceryl stearate - the two together form a super effective emulsifier duo that's salt and acid tolerant and works over a wide pH range. It also gives a "pleasing product aesthetics", so no wonder it's popular.

Also-called: Safflower Seed Oil | What-it-does: antioxidant, emollient | Irritancy: 0 | Comedogenicity: 0-2

The oil coming from the seeds of the yellow flowered safflower plant. Similar to other plant oils, it's loaded with nourishing and moisturizing fatty acids: it's a high linoleic acid oil (70%) and has only smaller amounts of oleic acid (11%) (this might be great for acne-prone skin). It also contains antioxidant vitamin E (44mg/100g alpha-tocopherol).

Also-called: lye | What-it-does: buffering

The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right. 

For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.  

Expand to read more

BTW, lye is not something new. It was already used by ancient Egyptians to help oil and fat magically turn into something else. Can you guess what? Yes, it’s soap. It still often shows up in the ingredient list of soaps and other cleansers.

Sodium hydroxide in itself is a potent skin irritant, but once it's reacted (as it is usually in skin care products, like exfoliants) it is totally harmless.

What-it-does: emollient, viscosity controlling | Irritancy: 1 | Comedogenicity: 2

An extremely common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams and lotions. It also helps to stabilize oil-water mixes (emulsions), though it does not function as an emulsifier in itself. Its typical use level in most cream type formulas is 2-3%.  

It’s a so-called fatty alcohol, a mix of cetyl and stearyl alcohol, other two emollient fatty alcohols.  Though chemically speaking, it is alcohol (as in, it has an -OH group in its molecule), its properties are totally different from the properties of low molecular weight or drying alcohols such as denat. alcohol. Fatty alcohols have a long oil-soluble (and thus emollient) tail part that makes them absolutely non-drying and non-irritating and are totally ok for the skin.

Arginine - goodie

A semi-essential (infants cannot synthesize it, but adults can) amino acid that is one of the primary building blocks of hair keratin and skin collagen. It's a natural moisturizing factor, a skin hydrator and might also help to speed up wound healing

Arginine usually has a positive charge (cationic) that makes it substantive to skin and hair (those are more negatively charged surfaces) and an excellent film former.  Thanks to the positive charge, it also creates a complex with AHAs (AHAs like to lose a hydrogen ion and be negatively charged, so the positive and the negative ions attract each other) that causes a "time-release AHA effect" and reduces the irritation associated with AHAs

We don't have description for this ingredient yet.

What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1

Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.

As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity. 

Expand to read more

As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types). 

Squalane - goodie
What-it-does: skin-identical ingredient, emollient | Irritancy: 0 | Comedogenicity: 1

It seems to us that squalane is in fashion and there is a reason for it. Chemically speaking, it is a saturated  (no double bonds) hydrocarbon (a molecule consisting only of carbon and hydrogen), meaning that it's a nice and stable oily liquid with a long shelf life. 

It occurs naturally in certain fish and plant oils (e.g. olive), and in the sebum (the oily stuff our skin produces) of the human skin. As f.c. puts it in his awesome blog post, squalane's main things are "emolliency, surface occlusion, and TEWL prevention all with extreme cosmetic elegance". In other words, it's a superb moisturizer that makes your skin nice and smooth, without being heavy or greasy.

Expand to read more

Another advantage of squalane is that it is pretty much compatible with all skin types and skin conditions. It is excellent for acne-prone skin and safe to use even if you have fungi-related skin issues, like seborrhea or fungal acne.

The unsaturated (with double bonds) and hence less stable version of Squalane is Squalene, you can read about it here >> 

Also-called: Vitamin E Acetate | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 0

It’s the most commonly used version of pure vitamin E in cosmetics. You can read all about the pure form here. This one is the so-called esterified version. 

According to famous dermatologist, Leslie Baumann while tocopheryl acetate is more stable and has a longer shelf life, it’s also more poorly absorbed by the skin and may not have the same awesome photoprotective effects as pure Vit E. 

Also-called: Form of Vitamin C | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 2

A form of skincare superstar, vitamin C. Even though we are massive vitamin C fans,  Ascorbyl Palmitate  (AP) is our least favorite. (Btw, if you do not know what the big deal with vitamin C is then you are missing out. You must go and read our geeky details about it.) 

So, AP is one of the attempts by the cosmetics industry to solve the stability issues with vitamin C while preserving its benefits,  but it seems to fall short on several things.

Expand to read more

What's the problem?

Firstly, it's stability is only similar to that of pure ascorbic acid (AA), which means it is not really stable. A great study in the Journal of Cosmetic Dermatology compared a bunch of vitamin C derivatives and this derivative was the only one where the study said in terms of stability that it's "similar to AA". Not really that good.

Second, a study that examined the skin absorption of vitamin C found that ascorbyl palmitate did not increase the skin levels of AA. This does not mean that ascorbyl palmitate cannot penetrate the skin (because it can, it's oil soluble and the skin likes to absorb oil soluble things) but this means that it's questionable if ascorbyl palmitate can be converted into pure Vit C in the skin. Even if it can be converted, the palmitate part of the molecule is more than the half of it, so the efficacy will not be good and we have never seen a serum that contains a decent (and proudly disclosed) amount of AP.  We are highly skeptical what effect a tiny amount of AP has in a formula.

Third, another study that wanted to examine the antioxidant properties of AP was surprised to find that even though AP does have nice antioxidant properties; following UVB radiation (the same one that comes from the sun) it also promotes lipid peroxidation and cytotoxicity. It was only an in-vitro study meaning that it was done on cell cultures and not on real people, but still, this also does not support the use of AP too much. 

The only good thing we can write about Ascorbyl Palmitate is that there is an in-vitro (made in the lab, not on real people) study showing that it might be able to boost collagen production.

Regarding the skin-brightening properties of pure vitamin C, this is another magic property AP does not have, or at least there is no data, not even in-vitro, about it.

Overall, Ascorbyl Palmitate is our least favorite vitamin C derivative. It is there in lots of products in tiny amounts (honestly, we do not really understand why), however, we do not know about any vitamin C serum featuring AP in high amounts. That is probably no coincidence. If you are into vitamin C, you can take a look at more promising derivatives here

Also-called: Form of Retinoids | What-it-does: cell-communicating ingredient | Irritancy: 1-3 | Comedogenicity: 1-3

It's an ester form of vitamin A (retinol + palmitic acid) that belongs to the "retinoid family". The retinoid family is pretty much the royal family of skincare, with the queen being the FDA-approved anti-aging ingredient tretinoin. Retinol is also a very famous member of the family, but it's like Prince William, two steps away from the throne. Retinyl palmitate will be then little Prince George, quite far (3 steps) away from the throne. 

By steps, we mean metabolic steps. Tretinoin, aka retinoic acid, is the active ingredient our skin cells can understand and retinyl palmitate (RP) has to be converted by our metabolic machinery to actually do something. The conversion is a 3 step one and looks like this:

Expand to read more

retinyl palmitate --> retinol -- > retinaldehyde --> all-trans-retinoic acid

As we wrote in our lengthy retinol description the problem is that the conversion is not terribly effective. The evidence that RP is still an effective anti-aging ingredient is not very strong, in fact, it's weak. Dr. Leslie Baumann in her fantastic Cosmetic Dermatology book writes that RP is topically ineffective

What's more, the anti-aging effectiveness is not the only questionable thing about RP. It also exibits questionable behaviour in the presence of UV light and was the center of a debate between the non-profit group, EWG (whose intentions are no doubt good, but its credibility is often questioned by scientists) and a group of scientists and dermatologists lead by Steven Q. Wang, MD,  director of dermatologic surgery at Memorial-Sloan Kettering Cancer Centre. 

Dr. Leslie Baumann wrote a great review of the debate and summarized the research available about retinyl palmitate here.  It seems that there is a study showing RP being photo protective against UVB rays but there is also a study showing RP causing DNA damage and cytotoxicity in association with UVA. 

We think that the truth lies somewhere in the middle, and we agree with Dr. Baumann's conclusion: "sufficient evidence to establish a causal link between RP and skin cancer has not been produced. Nor, I’m afraid, are there any good reasons to recommend the use of RP". We would add especially during the day!

Bottom line: If you wanna get serious about retinoids, RP is not your ingredient (retinol or tretinoin is!). However, if you use a product that you like and it also contains RP, there is no reason to throw it away. If possible use it at night, just to be on the safe side.

Phospholipids - goodie

A type of lipid that's the major (about 75%) component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient.

It has a water-loving head with two water-hating tails and this structure gives the molecule emulsifying properties. It is also often used to create liposomes, small spheres surrounded by phospholipid bi-layer designed to carry some active ingredient and help its absorption.

Also-called: Fermented Radish Root | What-it-does: antimicrobial/antibacterial, preservative

It's an alternative, natural preservative that comes from radishes fermented with Leuconostoc kimchii, a lactic acid bacteria that has been used to make traditional Korean dish, kimchi. During the fermentation process, a peptide is secreted from the bacteria that has significant antimicrobial properties

It is one of the more promising natural preservatives that can be used even alone (recommended at 2-4%), but it's not as effective as more common alternatives, like parabens or phenoxyethanol

Citric Acid - goodie
What-it-does: exfoliant, buffering

Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA. 

So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh. 

Expand to read more

There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin. 

But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation. 

A common little helper ingredient that helps water and oil to mix together, aka emulsifier.

What-it-does: chelating

Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes.

What-it-does: emulsifying, surfactant/cleansing | Irritancy: 0 | Comedogenicity: 0

It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 

We don't have description for this ingredient yet.

What-it-does: preservative

It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It’s not a strong one and doesn’t really work against bacteria, but more against mold and yeast. To do that it has to break down to its active form, sorbic acid. For that to happen, there has to be water in the product and the right pH value (pH 3-4). 

But even if everything is right, it’s not enough on its own. If you see potassium sorbate you should see some other preservative next to it too.

Expand to read more

BTW, it’s also a food preservative and even has an E number, E202.

What-it-does: preservative

A helper ingredient that helps to make the products stay nice longer, aka preservative. It works mainly against fungi. 

It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.

What-it-does: preservative

It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.

It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic. 

Expand to read more

Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10). 

It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.

You may also want to take a look at...

what‑it‑does solvent
Normal (well kind of - it's purified and deionized) water. Usually the main solvent in cosmetic products. [more]
what‑it‑does exfoliant
The most researched and well-known AHA exfoliant. It gently lifts off dead skin cells to reveal newer, fresher, smoother skin. In larger concentration (>10%) it's a proven collagen booster. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
A real oldie but a goodie. Great natural moisturizer and skin-identical ingredient that plays an important role in skin hydration and general skin health. [more]
what‑it‑does soothing | moisturizer/humectant
The famous aloe vera. A great moisturizer and anti-inflammatory ingredient that also helps wound healing and skin regeneration. [more]
what‑it‑does moisturizer/humectant | solvent
irritancy, com. 0, 1
An often used glycol that works as a solvent, humectant, penetration enhancer and also gives a good slip to the products. [more]
what‑it‑does emollient
A very common emollient that makes your skin feel nice and smooth. Comes from coconut oil and glycerin, it’s light-textured, clear, odorless and non-greasy. [more]
what‑it‑does emollient | emulsifying
irritancy, com. 0, 1-2
Waxy, white, solid stuff that helps water and oil to mix together and leaves the skin feeling soft and smooth. [more]
what‑it‑does surfactant/cleansing | emulsifying
irritancy, com. 0, 0
A commonly used water-soluble surfactant and emulsifier. [more]
what‑it‑does antioxidant | emollient
irritancy, com. 0, 0-2
Safflower Seed Oil - emollient plant oil with moisturizing fatty acids (linoleic: 70%, oleic: 11%) and antioxidant vitamin E (44mg/100g alpha-tocopherol). [more]
what‑it‑does buffering
Lye - A solid white stuff that’s very alkaline and used in small amount to adjust the pH of the product.  [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 1, 2
A super common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams. [more]
what‑it‑does skin-identical ingredient
An amino acid that is one of the primary building blocks of hair keratin and skin collagen. It's a natural moisturizing factor and might also help to speed up wound healing.  [more]
what‑it‑does chelating
what‑it‑does emollient
irritancy, com. 0, 1
A very common silicone that gives both skin and hair a silky smooth feel. It also forms a protective barrier on the skin and fills in fine lines. Also used for scar treatment. [more]
what‑it‑does skin-identical ingredient | emollient
irritancy, com. 0, 1
An emollient and natural moisturizer that can be found also in the sebum (oily stuff our skin produces). It leaves a nice non-greasy, non-heavy feeling on the skin. [more]
what‑it‑does antioxidant
irritancy, com. 0, 0
A form of vitamin E that works as an antioxidant. Compared to the pure form it's more stable, has longer shelf life, but it's also more poorly absorbed by the skin. [more]
what‑it‑does antioxidant
irritancy, com. 0, 2
An oil soluble vitamin C derivative that has mixed data about its effectiveness. [more]
what‑it‑does cell-communicating ingredient
irritancy, com. 1-3, 1-3
An ester form of vitamin A (retinol + palmitic acid) that is pretty much the least effective member of the retinoid family. Its anti-aging effects are quite questionable as well as its behavior in the presence of UVA light. (Use it at night if possible!) [more]
what‑it‑does skin-identical ingredient | emollient
A type of lipid that's the major component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient. It's also often used to create liposomes. [more]
what‑it‑does antimicrobial/antibacterial | preservative
It's an alternative, natural preservative that comes from radishes fermented with Leuconostoc kimchii, a lactic acid bacteria that has been used to make traditional Korean dish, kimchi. [more]
what‑it‑does exfoliant | buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [more]
what‑it‑does emulsifying | surfactant/cleansing
A common little helper ingredient that helps water and oil to mix together, aka emulsifier.
what‑it‑does chelating
Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes. [more]
what‑it‑does emulsifying | surfactant/cleansing
irritancy, com. 0, 0
It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 
what‑it‑does emulsifying | surfactant/cleansing
what‑it‑does preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]
what‑it‑does preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [more]