Peter Thomas Roth

Laser-Free Resurfacing Eye Serum

A water-soluble silicone (silicones are normally oil soluble) that makes your skin nice and smooth (aka emollient) and improves cushion, texture, and slip in the formula. 

• It's a helper ingredient that improves the freeze-thaw stability of products
• It's also a solvent, humectant and to some extent a penetration enhancer
• It has a bad reputation among natural cosmetics advocates but cosmetic scientists and toxicology experts do not agree (read more in the geeky details section)

• A multi-functional skincare superstar with several proven benefits for the skin
• Great anti-aging, wrinkle smoothing ingredient used at 4-5% concentration
• Fades brown spots alone or in combination with amino sugar, acetyl glucosamine
• Increases ceramide synthesis that results in a stronger, healthier skin barrier and better skin hydration
• Can help to improve several skin conditions including acne, rosacea, and atopic dermatitis

• 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

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

• It's a super common and super debated skincare ingredient
• It has several benefits: great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial
• It can be very drying if it's in the first few ingredients on an ingredient list
• Some experts even think that regular exposure to alcohol damages skin barrier and causes inflammation though it's a debated opinion (read more in geeky details tab)

A super commonly used 5 unit long, cyclic structured silicone that is water-thin and does not stay on the skin but evaporates from it (called volatile silicone). Similar to other silicones, it gives skin and hair a silky, smooth feel. 

It's often combined with the non-volatile (i.e. stays on the skin) dimethicone as the two together form a water-resistant, breathable protective barrier on the skin without a negative tacky feel.

This ingredient name is not according to the INCI-standard. :( What, why?!

Squalene is an oily liquid that originally comes from shark liver but luckily it can also be found in a couple of plant oils. Olive (0.6%), peanut (0.1%) and pumpkin (0.35%) oils contain it, though not in huge amounts. 

What contains more of it, is the sebum (the oily stuff) that our skin produces. About 13% of human sebum is squalene, which means that it’s an important skin-identical ingredient and NMF (natural moisturizing factor). 

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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. 

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A white powdery thing that's the major component of glass and sand. In cosmetics, it’s often in products that are supposed to keep your skin matte as it has great oil-absorbing abilities. It’s also used as a helper ingredient to thicken up products or suspend insoluble particles. 

A  clear, colorless oil-like liquid that makes the skin feel smooth and nice (aka emollient) and it does so without it being greasy.

What's more, it can even reduce the heavy, greasy feel in products with high oil content. It's also fast-spreading meaning that it gives the formula a good, nice slip. It absorbs quickly into the skin and helps other ingredients to penetrate quicker and deeper. 

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A  clear, colorless and odorless, highly volatile (meaning it does not absorb into the skin but evaporates from it) liquid that's used as an emollient. It gives a nice non-oily light skin feel and it can improve the slip of the formula without leaving a tacky residue behind.

It's also popular in make-up products as its volatility makes mascaras and foundations last longer. If that would not be enough, it's also an excellent solvent, and it's a regular not only on the ingredients lists of make-ups but also on makeup removers.  

Hello, our favorite molecule that helps us wake up in the morning and then keeps us going through the day. As a super well-known stimulant from coffee, tea and plenty of other soft drinks, Caffeine needs no introduction. So we will skip right to the part where we talk about what the hell it does in so-so many cosmetic products.

Looking at the research, we were surprised to find how versatile Caffeine is. It is a small, water-loving molecule with pretty good skin penetration abilties. Once in the skin, it has nice antioxidant properties, meaning that it reduces the formation of evil free radicals and it might even be useful in preventing UV-induced skin cancers. 

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A big molecule created from repeated subunits (a polymer of acrylic acid) that magically converts a liquid into a nice gel formula.  It usually has to be neutralized with a base (such as sodium hydroxide) for the thickening to occur and it creates viscous, clear gels that also feel nice and non-tacky on the skin. No wonder, it is a very popular and common ingredient.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

A natural plant extract coming from the bark of the maritime pine that grows along the coast of southwest France. The extract contains potent antioxidant molecules, mainly procyanidins and phenolic acids.  Horphag Research trademarked the name 'Pycnogenol', which refers to a standardized, high-active content version of the pine bark extract. 

Pycnogenol is a very well researched ingredient with more than 370 published studies and review articles. Most of these are in-vitro (made in the lab, not on real people) or analyse Pycnogenol when taken orally. It's clear from them that Pycnogenol has a load of health benefits including antioxidant, anti-inflammatory, and anticarcinogenic magical properties (and a bunch of other things such as improving cognitive function, relieving premenstrual symptoms, or enhancing microcirculation). 

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We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

It's a biotechnological marine alternative to famous IT-moisturizer and humectant hyaluronic acid (HA). It's obtained by the fermentation of a marine bacterial strain. According to the manufacturer it's rich in the same monosaccharide, called glucuronic acid as HA,  hence it has a similar effect on the skin. Moisturization and wrinkle smoothing are the two main promises.  

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

A polysaccharide (a big sugar molecule) coming from the edible fruit bodies of the Silver Ear mushroom in China. It's claimed to be an awesome moisturizer with slightly greater water-holding capacities than HA. We wrote more about Tremella here >> 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

A skin-brightening peptide that is claimed to have a unique mechanism of action on lightening both constitutive (our default skin color) and facultative (such as tanning) pigmentation. It works by inhibiting the MITF gene that plays an important role in controlling melanin producing skin cells called melanocytes.

In the in-vivo (made on real people) test of the manufacturer, 23 Asian volunteers used a 5% ß-White formula for 56 days twice a day and 87% reported a more uniform skin tone and 91% felt that their skin was brighter than before.

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A six amino acid peptide that is claimed to improve firmness and skin tone. Its amino acid sequence is Val-Gly-Val-Ala-Pro-Gly that is also called the "spring fragment" and is repeated six times in the important skin protein, elastin molecule.

The manufacturer made a double-blind, one-month long clinical study on 10 women and found that twice a day application of 4%  Biopeptide El improved skin firmness by 33% and skin tone by 20%. 

A four amino acid peptide with the amino sequence of glycine-glutamine-proline-arginine. It is attached to palmitic acid (a fatty acid)  to increase oil solubility and skin penetration. 

It works by reducing the production of the signal molecule, inteleukin-6 (IL-6) which promotes inflammation in the skin and less inflammation means slower degradation of important things (like collagen) that results in younger looking skin for a longer time. 

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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:

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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. 

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.

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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.

An amino acid sugar that can be found in the skin and does there good and important things. One of them is that it's a precursor for the biosynthesis of superstar moisturizer, hyaluronic acid. So acetyl glucosamine itself is also an important skin-identical ingredient and natural moisturizing factor.

But that is not all, acetyl glucosamine has two other great properties proved by double-blind clinical trials. First, it's a promising ingredient against wrinkles:  2% can improve wrinkles, particularly in the eye area.

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We don't have description for this ingredient yet.

A type of lipid that is used in liposome technology. It has a special chemical structure (a water-loving PEG head with two oil-loving tails) that allows forming thermodynamically stable liposomes.

This means when Peg-12 Glyceryl Dimyristate is mixed with water it forms tiny bilayered circles (with an active ingredient in the middle of it) spontaneously. This is useful both for stabilizing unstable ingredients (such as pure Vitamin C) as well as for solubilizing difficult ingredients (such as cholesterol). 

We don't have description for this ingredient yet.

It’s the - sodium form - cousin of the famous NMF, hyaluronic acid (HA). If HA does not tell you anything we have a super detailed, geeky explanation about it here.  The TL; DR version of HA is that it's a huge polymer (big molecule from repeated subunits) found in the skin that acts as a sponge helping the skin to hold onto water, being plump and elastic. HA is famous for its crazy water holding capacity as it can bind up to 1000 times its own weight in water.

As far as skincare goes, sodium hyaluronate and hyaluronic acid are pretty much the same and the two names are used interchangeably. As cosmetic chemist kindofstephen writes on reddit  "sodium hyaluronate disassociates into hyaluronic acid molecule and a sodium atom in solution". 

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Simply alcohol refers to ethanol and it's a pretty controversial ingredient. It has many instant benefits: it's a great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial. No wonder it's popular in toners and oily skin formulas. 

The downside is that it can be very drying if it's in the first few ingredients on an ingredient list. 

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A sugar beet derived amino acid derivative with nice skin protection and moisturization properties. Betain's special thing is being an osmolyte, a molecule that helps to control cell-water balance.  It is also a natural osmoprotectant, meaning that it attracts water away from the protein surface and thus protects them from denaturation and increases their thermodynamic stability. 

It also gives sensorial benefits to the formula and when used in cleansers, it helps to make them milder and gentler. 

We don't have description for this ingredient yet.

A cellulose-derived helper ingredient that is created by attaching a water-hating part (cetyl group) to the water-loving thickener, Hydroxyethylcellulose. The resulting thing, Cetyl Hydroxyethylcellulose is also a thickener but with some surface active properties (as part of the molecule is water-loving and part of it is oil loving). Thanks to its surface-active properties, it also works as an emulsion stabilizer. 

A very common ingredient that can be found in all cell membranes. In cosmetics it's quite the multi-tasker: it's an emollient and water-binding ingredient but it's also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

A waxy solid material that helps oil and water to mix together, aka emulsifier. It is derived from the fatty alcohol called stearyl alcohol by ethoxylating it and thus making the molecule more water-soluble.

The end result is a mostly water-loving emulsifier, also called solubilizer that can help to dissolve small amounts of oil-loving ingredients into water-based products. Or it can be combined with more oil-loving emulsifiers (such as its sister, Steareth-2) to create stable emulsions. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

It's the chemically chopped up version of normal lecithin. Most often it's used to create liposomes and to coat and stabilize other ingredients. 

We don't have description for this ingredient yet.

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.

The big brother of glycerin. It's also a natural moisturizing factor that reduces water evaporation from the upper layer of the skin and helps to keep water in the skin so that it stays nicely hydrated.

Compared to glycerin, it has a larger molecular structure (kind of a double glycerin). Thanks to this, it penetrates slower into the skin but gives longer lasting moisture and less sticky, better skin-feel.

We don't have description for this ingredient yet.

A type of silicone elastomer (rubber-like material with both viscosity and elasticity) whose major function is forming a nice film on the skin.

It is also cosmetically very elegant with a non-tacky, non-oily and smooth skin feel. It also works as a stable delivery system of active materials, has sebum absorption and control properties and upon application, it transforms into a matte appearance with a powdery after feel.

We don't have description for this ingredient yet.

A clear, oil-soluble, "cosmetically-elegant" liquid that is the most commonly used chemical sunscreen. It absorbs UVB radiation (at wavelengths: 280-320 nm) with a peak protection at 310nm. 

It only protects against UVB and not UVA rays (the 320-400 nm range) – so always choose products that contain other sunscreens too. It is not very stable either, when exposed to sunlight, it kind of breaks down and loses its effectiveness (not instantly, but over time - it loses 10% of its SPF protection ability within 35 mins). To make it more stable it can be - and should be - combined with other sunscreen agents to give stable and broad-spectrum protection (the new generation sunscreen agent, Tinosorb S is a particularly good one for that).

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The famous Avobenzone. It is a special snowflake as it is the only globally available chemical sunscreen agent that provides proper UVA protection (in the US, new generation sunscreen agents are not approved because of impossible FDA regulations). It is the global gold standard of UVA protection and is the most used UVA sunscreen in the world. 

It gives very good protection across the whole UVA range (310-400 nm that is both UVA1 and UVA2) with a peak protection at 360 nm. The problem with it, though, is that it is not photostable and degrades in the sunlight. Wikipedia says that avobenzone loses 36% of its UV-absorption capacity after just one hour of sunlight (yep, this is one of the reasons why sunscreens have to be reapplied after a few hours).

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A helper ingredient that usually comes to the formula coupled with PEG-40 Hydrogenated Castor Oil. The two together work as surfactants and oil solubilizers. It's a non-sticky duo that works at low concentration and is often used to solubilize fragrance components into water-based formulas.

A colorless to light yellowish oily liquid that works as a UVB (280-320nm) sunscreen filter with a peak absorbance at 306 nm. It's not a strong filter in itself, it's always used in combination with other sunscreen agents to further enhance the SPF and to solubilize other solid UV filters.

It has a good safety profile and is allowed to be used at a max concentration of 5% both in the US and in Europe (10% is allowed in Japan).

A mildly viscous, amber-colored liquid with fatty odor, made from Castor Oil and polyethylene glycol (PEG).

If it were a person, we’d say, it’s agile, diligent & multifunctional. It’s mostly used as an emulsifier and surfactant but most often it is used to solubilize fragrances into water-based formulas.

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.  

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An antimicrobial preservative that helps your products not to go wrong too quickly. It works especially well against bacteria, specifically gram-negative species, yeast, and mold.

Somewhat controversial, it belongs to an infamous family of formaldehyde-releasers. That is, it slowly breaks down to form formaldehyde when it is added to a formula. We have written more about formaldehyde-releasing preservatives and the concerns around them at Dmdm Hydantoin, but do not get too scared, those are more theories than proven facts.

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The most common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon. 

Apart from the general controversy around parabens (we wrote about it more here), there is a 2006 in-vitro (made in the lab not on real people) research about methylparaben (MP) showing that when exposed to sunlight, MP treated skin cells suffered more harm than non-MP treated skin cells. The study was not done with real people on real skin but still - using a good sunscreen next to MP containing products is a good idea. (Well, in fact using a sunscreen is always a good idea. :))

A very common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon.

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. 

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We don't have description for this ingredient yet.

A very common type of feared-by-everyone-mostly-without-scientific-reason paraben. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon. Read more about parabens here >>

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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.

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We don't have description for this ingredient yet.

A mild, natural preservative that usually comes to the formula together with its other mild preservative friends, such as Benzoic Acid and/or Dehydroacetic Acid. Btw, it's also used as a food preservative.

• It's one of the gold standard ingredients for treating problem skin
• It can exfoliate skin both on the surface and in the pores
• It's a potent anti-inflammatory agent
• It's more effective for treating blackheads than acne
• For acne combine it with antibacterial agents like benzoyl peroxide or azelaic acid

We don't have description for this ingredient yet.

• 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

An abbreviation that pops up on a lot of ingredient lists. It stands for EthyleneDiamineTetraacetic Acid and it's a famous molecule for being an excellent chelating agent, i.e. a molecule that can bind to metal ions (coming usually from water) and make them harmless in a cosmetic formula. With a chelating agent, cosmetic formulas stay nice longer.

EDTA is an acid molecule and its salt versions are even more often used, such as the super common Disodium EDTA. 

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. 

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The sodium salt of salicylic acid. CosIng (the official EU cosmetic ingredient database) says that it's a preservative and helps to make the product taste bad (called denaturant), while some manufacturer claims that it has exfoliating properties and is antimicrobial. It's good to know, that the salt of an exfoliant is a neutralized form, so if you want to go for exfoliation stick to the pure acid. 

Similar to other glycols, it's a helper ingredient used as a solvent, or to thin out thick formulas and make them more nicely spreadable. 

Hexylene Glycol is also part a preservative blend named Lexgard® HPO, where it helps the effectiveness of current IT-preservative, phenoxyethanol. 

It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol. 

The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.

Carmine is a natural pigment that gives a bright, strawberry red shade. It counts as a special snowflake as it is the only organic pink/red colorant permitted for use around the eye area in the US.

Outside of the US though, it is not that often used, as unlike most other colorants (that tend to be synthetic or if natural, plant-derived), Carmine is animal-derived and comes from an insect called Coccus cacti. This makes it both very expensive and excludes it from animal-friendly, vegan cosmetic products.  

A super versatile and common mineral powder that comes in different particle sizes. It is a multi-tasker used to improve skin feel, increase product slip, give the product light-reflecting properties, enhance skin adhesion or serve as an anti-caking agent.

It is also the most commonly used "base" material for layered composite pigments such as pearl-effect pigments. In this case, mica is coated with one or more metal oxides (most commonly titanium dioxide) to achieve pearl effect via the physical phenomenon known as interference.