Aqua
Also-called: 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.
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.
Diethylhexyl Adipate
What-it-does: emollient, solvent
We don't have description for this ingredient yet.
Octyldodecanol
What-it-does: emollient, perfuming
A clear, slightly yellow, odorless oil that's a very common, medium-spreadingemollient. It makes the skin feel nice and smooth and works in a wide range of formulas.
3-O-Ethyl Ascorbic Acid - goodie
Also-called: Form of Vitamin C, 3-O-Ethyl Ascorbate, EAC;Ethyl Ascorbic Acid | What-it-does: antioxidant, skin brightening
A very stable and promising form of the skincare superstar, Vitamin C. If you do not know why Vitamin C is such a big deal in skin care, you can catch up here. In short, Vitamin C has three proven magic abilities: antioxidant, collagen booster, and skin brightener. The problem, though, is that it's very unstable, turns brown and becomes ineffective in no time (after a few month) and the cosmetics industry is trying to come up with smart derivatives that are stable and have the magic properties of pure Vitamin C.
Ethyl Ascorbic Acidor EAC for short is an "etherified derivative of ascorbic acid" that consists of vitamin C and an ethyl group bound to the third carbon position. This makes Vitamin C very stable and soluble in bothwater and oil.
However, for a Vitamin C derivative to workit's not enough just to be stable, they also have to be absorbed into the skin and be converted there to pure Vitamin C. We have good news regarding the absorption: on top of manufacturer claims, there is somedata (animal study) demonstrating in can get into the skin, and it seems to be better at it than Ascorbyl Glucoside, another vitamin C derivative.
Regarding conversion, we can cite onlyamanufacturers claimsaying thatEAC ismetabolized in the skin into pure ascorbic acid (and the ascorbic acid content of EAC is very high - 86,4% - compared to the usual 50-60% Vitamin C content of other derivatives).
As for the three magic abilities of Vitamin C, we again mostly haveonly themanufacturer's claims, but at least those are very promising. EAC seems to have both anantioxidant and anti-inflammatory effect, and it's claimed to be able to boost the skin's collagen production. The strong point of EACthoughis skin brightening. On top of manufacturer claims, there is also clinical in-vivo (tested on real people) data showing that 2% EAC can improve skin tone and whiten the skin.
Overall, Ethyl Ascorbic Acid is a very promising but not a fully proven Vitamin C derivative. It's worth a try, especiallyif you are after Vitamin C's skin-brightening effects.
Glyceryl Stearate
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 calledstearic acid. It can be produced from most vegetable oils (in oils three fattyacidmolecules 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.
It also occurs naturally in our body and is used as a food additive. As cosmetic chemistColins writes it, "its safety really is beyond any doubt".
PEG-100 Stearate
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 nicelytogether.
It's often paired with glyceryl stearate- the twotogether forma 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.
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 for dry skin at higher concentrations up to 20-40%
- High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Also-called: Sepinov EMT 10 | What-it-does: viscosity controlling, emulsion stabilising
This long-named, polymer molecule (big molecule from repeated subunits) is a helper ingredient that's good at emulsifying andstabilizing oils into water-based formulas. Italso acts as a thickening and gelling agent thatcreates nice, non-sticky and supple textures.It works over a very wide pH range (3-12)and can be used to thicken up low-ph formulas, such as exfoliants. Its recommended used range is 0.3-3%.
Panthenol - goodie
Also-called: Pro-Vitamin B5 | What-it-does: soothing, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
An easy-to-formulate, commonly used, nice to have ingredient that’s also called pro-vitamin B5. As you might guess from the “pro” part, it’s a precursor to vitamin B5 (whose fancy name is pantothenic acid).
Its main job in skincare products is to moisturise the skin. It’s a humectant meaning that it can help the skin to attract water and then hold onto it. There is also research showing that panthenol can help our skin to produce more lovely lipids that are important for a strong and healthy skin barrier.
Another great thing about panthenol is that it has anti-inflammatory and skin protecting abilities. A study shows that it can reduce the irritation caused by less-nice other ingredients (e.g. fragrance, preservatives or chemical sunscreens) in the product.
Research also shows that it might be useful for wound healing as it promotes fibroblast (nice type of cells in our skin that produce skin-firming collagen) proliferation.
If that wasn’t enough panthenol is also useful in nail and hair care products. A study shows that a nail treatment liquide with 2% panthenol could effectively get into the nail and significantly increase the hydration of it.
As for the hair the hydration effect is also true there. Panthenol might make your hair softer, more elastic and helps to comb your hair more easily.
Dodecane
What-it-does: emollient, perfuming
A natural based very light and highly spreading emollient that can be analternative to water-thin, volatile silicone, Cyclopentasiloxane.
Tetradecane
What-it-does: perfuming
We don't have description for this ingredient yet.
Helianthus Annuus (Sunflower) Seed Extract
We don't have description for this ingredient yet.
Sodium Hyaluronate - goodie
What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
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 kindofstephenwrites on reddit "sodium hyaluronate disassociates into hyaluronic acid molecule and a sodium atom in solution".
In spite of this, if you search for "hyaluronic acid vs sodium hyaluronate" you will find on multiple places that sodium hyaluronate is smaller and can penetrate the skin better. Chemically, this is definitely not true, as the two forms are almost the same, both are polymers and the subunits can be repeated in both forms as much as you like. (We also checkedProspector for sodium hyaluronate versions actually used in cosmetic products and found that the most common molecular weight was 1.5-1.8 million Da that absolutely counts as high molecular weight).
What seems to be a true difference, though, is that the salt form is more stable, easier to formulate andcheaper so it pops up more often on the ingredient lists.
If you wanna become a real HA-and-the-skin expert you can read way more about the topic at hyaluronic acid(including penetration-questions, differences between high and low molecular weight versions and a bunch of references to scientific literature).
Allantoin - goodie
What-it-does: soothing | Irritancy: 0 | Comedogenicity: 0
Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmeticproductsis produced synthetically.
It's not only soothing but it' also skin-softening and protecting and can promote wound healing.
Tocopheryl Acetate
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.
Plankton Extract
We don't have description for this ingredient yet.
Urea - goodie
Also-called: Carbamide | What-it-does: skin-identical ingredient, moisturizer/humectant
Yes, it's the thing that can be found naturally in pee. And in the skin. It is an awesome natural moisturizing factor, aka NMF.NMFs are important components that help the skin to hold onto water and keep it plump, elastic and hydrated. Urea makes up about 7% of NMFs next to other things such as amino acids (40%), PCA (12%) or Lactate (12%).
What makes urea special, is that it is not only a simple moisturizer, but it is thought to be a "small-molecule regulator of epidermal structure and function" meaning that it has a bunch of extra biological activities. It acts asa mild keratolytic agent(some of its moisturizingaction is thought to come from urea's abilityto break down bonds in the protein called filaggrin and thus freeing up amino acids in the skin), enhancesantimicrobial peptide expression and improvesskin barrier function.
Being a mild keratolytic agent and strong moisturizermeans that high-percentage (10-40%) urea treatments are found effective in a bunch of skin disorders connected to excessive dryness and malfunctioning skin barrier such as ichthyosis, xerosis, psoriasis,eczema and seborrheic dermatitis.
Overall, just like glycerin, urea is a real oldie but a goodie, a nice ingredientin anymoisturizer.
Hydroxypropyl Starch Phosphate
What-it-does: viscosity controlling
We don't have description for this ingredient yet.
Pentylene Glycol
What-it-does: solvent, moisturizer/humectant
A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as anemulsion stabilizer, solvent and a broad spectrum antimicrobial. According to manufacturer info, it's also amoisturizer and helps to make the product feel great on the skin. It works synergistically with preservatives and helps to improvewater-resistance of sunscreens.
Acrylates/C10-30 Alkyl Acrylate Crosspolymer
What-it-does: viscosity controlling, emulsion stabilising
Though its long name does not reveal it, this polymer molecule (big molecule from repeated subunits or monomers) is a relative to the super common, water-loving thickener, Carbomer. Both of them are big molecules that contain acrylic acid units, butAcrylates/C10-30 Alkyl Acrylate Crosspolymer also contains some other monomers that are hydrophobic, i.e. water-hating.
This means that our molecule is part water- and part oil-loving, so it not only works as a thickener but also as an emulsion stabilizer. It is very common in gel-type formulas that also contain an oil-phase as well as in cleansers as it also works with most cleansing agents (unlike a lot of other thickeners).
Citric Acid
What-it-does: 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.
There is also some research showing that citric acid with regular use (think three monthsand 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.
Diethyl Succinate
What-it-does: solvent
We don't have description for this ingredient yet.
Fructose - goodie
What-it-does: moisturizer/humectant
Fancy name for fruit sugar. It has nice water-binding properties and helps to keep skin hydrated.
Glucose - goodie
What-it-does: moisturizer/humectant
A fancy name for sugar. Luckily when you put it on your skin it's good for you not like when you eat it. :) It has water-binding properties, which means that it helps to keep your skin nice and hydrated.
Maltose
What-it-does: moisturizer/humectant
We don't have description for this ingredient yet.
Trehalose - goodie
What-it-does: moisturizer/humectant
A type of sugar that haswater-bindingproperties and helps to keep your skinhydrated.
Tocopherol - goodie
Also-called: Vitamin E | What-it-does: antioxidant | Irritancy: 0-3 | Comedogenicity: 0-3
- Primary fat-soluble antioxidant in our skin
- Significant photoprotection against UVB rays
- Vit C + Vit E work in synergy and provide great photoprotection
- Has emollient properties
- Easy to formulate, stable and relatively inexpensive
Read all the geeky details about Tocopherol here >>
Disodium EDTA
What-it-does: chelating
Super common little helper ingredient thathelps 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.
It is typically used in tiny amounts, around 0.1% or less.
Triethanolamine
What-it-does: buffering | Irritancy: 0 | Comedogenicity: 2
It’s a little helper ingredient that helps to set the pH of a cosmetic formulation to be just right. It’s very alkaline (you know the opposite of being very acidic): a 1% solution has a pH of around 10.
It does not have the very best safety reputation but in general, you do not have to worry about it.
What is true is that if a product contains so-called N-nitrogenating agents (e.g.: preservatives like 2-Bromo-2-Nitropropane-1,3-Diol, 5-Bromo-5-Nitro- 1,3-Dioxane or sodium nitrate - so look out for things with nitro, nitra in the name) that together with TEA can form some not nice carcinogenic stuff (that is called nitrosamines). But with proper formulation that does not happen, TEA in itself is not a bad guy.
But let’s assume a bad combination of ingredients were used and the nitrosamines formed. :( Even in that case you are probably fine because as far as we know it cannot penetrate the skin.
But to be on the safe side, if you see Triethanolamine in an INCI and also something with nitra, nitro in the name of it just skip the product, that cannot hurt.
Sodium Chloride
Also-called: Salt | What-it-does: viscosity controlling
Sodium chloride is the fancy name of salt. Normal, everyday table salt.
If (similar to us) you are in the weird habit of reading the label on your shower gel while taking a shower, you might have noticed that sodium chloride is almost always on the ingredient list. The reason for this is that salt acts as a fantastic thickener in cleansing formulas created with ionic cleansing agents(aka surfactants) such as Sodium Laureth Sulfate. A couple of percents (typically 1-3%) turns a runny surfactant solution into a nice gel texture.
If you are into chemistry (if not, we understand, just skip this paragraph), the reason is that electrolytes (you know, the Na+ and Cl- ions) screen the electrostatic repulsion between the head groups of ionic surfactants and thus support the formation of long shaped micelles (instead of spherical ones) that entangle like spaghetti, and viola, a gel is formed. However, too much of it causes the phenomenon called "salting out", and the surfactant solution goes runny again.
Other than that, salt also works as an emulsion stabilizer inwater-in-oil emulsions, that is when water droplets are dispersed in the outer oil (or silicone) phase. And last but not least, when salt is right at the first spot of the ingredient list (and is not dissolved), the product is usually a body scrub where salt is thephysical exfoliating agent.
Sodium Lactate - goodie
What-it-does: buffering, moisturizer/humectant
The sodium salt oflactic acid. It's a great skin moisturizer and also used to regulate the pH value of the cosmetic formula. It's a natural ingredient approved by bothECOCERT and COSMOS.
Sodium PCA - goodie
Also-called: Sodium Pyrrolidone Carboxylic Acid | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
PCA stands for Pyrrolidone Carboxylic Acid and though it might not sound like it, it is a thing that can be found naturally in our skin. The sodium salt form of PCA is an important skin-identical ingredient and great natural moisturizer that helps the skin to hold onto water and stay nicely hydrated.
Sodium Hydroxide
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.
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 itselfis a potent skin irritant, but once it's reacted (as it is usually in skin care products, like exfoliants) it is totallyharmless.
Parfum - icky
Also-called: Fragrance, Parfum;Parfum/Fragrance | What-it-does: perfuming
Exactly what it sounds: nice smelling stuff put into cosmetic products so that the end product also smells nice. Fragrance in the US and parfum in the EU is a generic term on the ingredient list that is made up of 30 to 50 chemicals on average (but it can have as much as 200 components!).
If you are someone who likes to know what you put on your face then fragrance is not your best friend - there's no way to know what’s really in it.
Also, if your skin is sensitive, fragrance is again not your best friend. It’s the number one cause of contact allergy to cosmetics. It’s definitely a smart thing to avoid with sensitive skin (and fragrance of any type - natural is just as allergic as synthetic, if not worse!).
Ethylhexylglycerin
What-it-does: preservative, deodorant
If you have spottedethylhexylglycerinon the ingredient list, most probably you will see there also the current IT-preservative,phenoxyethanol. They are good friends becauseethylhexylglycerincan boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too.
Also,it's an effective deodorant and a medium spreadingemollient.
Phenoxyethanol
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.
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.
Limonene - icky
What-it-does: perfuming, solvent, deodorant
A supercommon and cheap fragrance ingredient. It's in many plants, e.g. rosemary, eucalyptus, lavender, lemongrass, peppermint and it's the main component (about 50-90%) of the peel oil of citrus fruits.
It does smellnice but the problemis that it oxidizes on air exposure and the resulting stuff is not good for the skin. Oxidizedlimonene cancause allergic contact dermatitis and counts asa frequent skin sensitizer.
Limonene's nr1 function is definitely being a fragrance component, but there are several studies showing that it's also a penetration enhancer, mainly for oil-loving components.
All in all, limonene has some pros and cons, but - especially if your skin is sensitive -the cons probably outweigh the pros.
Linalool - icky
What-it-does: perfuming, deodorant
Linalool is a super common fragrance ingredient. It’s kind of everywhere - both in plants and in cosmetic products. It’s part of 200 natural oils including lavender, ylang-ylang, bergamot, jasmine, geranium and it can be found in 90-95% of prestige perfumes on the market.
The problem with linalool is, that just like limoneneit oxidises on air exposure and becomes allergenic. That’s why a product containing linalool that has been opened for several months is more likely to be allergenic than a fresh one.
A study made in the UK with 483 people tested the allergic reaction to 3% oxidised linalool and 2.3% had positive test results.
Citral - icky
What-it-does: perfuming
It’s a common fragrance ingredient that smells like lemon and has a bittersweet taste. It can be found in many plant oils, e.g. lemon, orange, lime or lemongrass.
It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential. Best to avoid if your skin is sensitive.