Gamma Hydroxy
Ingredients overview
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Skin doctors Gamma HydroxyIngredients explained
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.
- 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
Arctostaphylos Uva-Ursi is a little plant with nice red berries that lives in the North and is also called bearberry or kinnikinnick. According to Wikipedia the uva-ursi part means “grape of the bear”.
As for skincare bearberry is interesting because it contains the well-known skin lightening agent arbutin. The leaves contain 5-15% percent of it and might be able to help fading brown spots on the skin. Also, kinnikinnick (such a cool name :)) is an antioxidant and has some antibacterial activity.
A form of skincare superstar, Vitamin C. If you do not know, what the big deal about Vitamin C is, click here and read all about it, we will wait here for you.
So now you know that pure vitamin C (aka ascorbic acid, AA) is really unstable and hard to formulate so the cosmetics industry is coming up with a bunch of derivatives to solve the problem and Magnesium Ascorbyl Phosphate (or MAP) is one of them.
MAP does solve the stability problem: it's stable up to pH 7, so far so good. What is not so good is that, as the great review study about vitamin C derivatives in the Journal of Cosmetic Dermatology writes, MAP is "at very best, poorly absorbed in comparison to AA."
Moreover, derivatives not only have to be absorbed into the skin, they also have to be converted into pure AA. The good news is that in-vitro data shows that MAP does convert, but the bad news is we do not really know if the same is true on real, living human skin. Even if it does, we don't know how good the conversion rate is (but to be fair the same is true for all other derivatives).
Regarding the three magic abilities of pure vitamin C (antioxidant, collagen booster, skin brightener), there is no published data about MAP's antioxidant or photoprotection capabilities. We have better news about the other two things: in-vitro data shows that MAP can boost collagen synthesis similar to AA (though in the case of AA it's proven in-vivo) and even better, MAP is proven to work as a skin brightener in-vivo (on real people).
Bottom line: when it comes to vitamin C derivatives, MAP is definitely an option. We especially recommend it if you are after skin brightening as this seems to be the strongest point of MAP.
- 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
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).
Regarding safety, there are also some concerns around Octinoxate. In vitro (made in the lab not on real people) and animal studies have shown that it may produce hormonal (estrogen-like) effects. Do not panic, the studies were not conducted under real life conditions on real human people, so it is probably over-cautious to avoid Octinoxate altogether. However, if you are pregnant or a small child (under 2 yrs. old), choose a physical (zinc oxide/titanium dioxide) or new-generation Tinosorb based sunscreen, just to be on the super-safe side. :)
Overall, Ethylhexyl Methoxycinnamate is an old-school chemical sunscreen agent. There are plenty of better options for sun protection today, but it is considered "safe as used" (and sunscreens are pretty well regulated) and it is available worldwide (can be used up to 10% in the EU and up to 7.5% in the US).
Cyclomethicone is not one type of silicone, but a whole mixture of them: it's a mix of specific chain length (4 to 7) cyclic structured silicone molecules. (There seems to be a confusion on the internet whether Cyclomethicone and Cyclopentasiloxane are the same. They are not the same, but Cyclopentasiloxane is part of the mixture that makes up Cyclomethicone).
All the silicones in the Cyclomethicone mixture are volatile, meaning they evaporate from the skin or hair rather than stay on it. This means that Cyclomethicone has a light skin feel with none-to-minimal after-feel. It also makes the formulas easy to spread and has nice emollient properties.
A chemical sunscreen agent that absorbs UVB and short UVA rays (280-350nm) with its peak protection at 288 nm. Unlike many other chemical sunscreens, it is highly stable but its UV absorbing abilities are weak so it always has to be combined with other sunscreen agents for proper protection. More often than not, it's used as a photostabilizer rather than a proper sunscreen agent as it can protect formulas nicely from UV damage.
Regarding safety, BP-3 is somewhat controversial. First, its molecules are small (228 Da) and very lipophilic (oil loving) and these properties result in very good absorption. The problem is that you want sunscreens on the top of your skin and not in your bloodstream, so for BP-3 this is a problem. In fact, it absorbs so well that 4 hours after application of a sunscreen product with BP-3, it can be detected in urine.
Another concern of BP-3 is that it shows some estrogenic activity, though it's probably not relevant when applied topically to the skin. Estrogenic activity was confirmed only in-vitro (in test tubes) and when taken orally by lab animals, and not when used topically as you would normally. In fact, a 2004 follow-up study to examine the estrogenic effect of sunscreens when used topically on the whole body found that "the endogenous levels of reproductive hormones were unaffected" (even though BP-3 could be detected both in plasma and urine, so its absorption is no doubt too good).
If that was not enough, Wikipedia claims that BP-3 is nowadays the most common allergen found in sunscreens, and the always-trustworthy smartskincare writes that "[benzophenones] have been shown in some studies to promote the generation of potentially harmful free radicals".
On the up side, sunscreens are pretty well regulated in several parts of the world, and BP-3 is considered "safe as used" and is an allowed sunscreen agent everywhere. It can be used in concentrations of up to 10% in the EU and up to 6% in the US.
Overall, BP-3 is probably our least favorite sunscreen agent and we prefer sunscreens without it. However, if you find a formula that you love and contains BP-3, we do not think that you should throw it away. A sunscreen with BP-3 is definitely better than no sunscreen.
- 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 handy multi-tasker, white to light yellowish oil-loving wax that works very well in oil-in-water emulsions. It makes your skin feel nice and smooth (emollient), stabilizes oil-water mixes and gives body to them.
Oh, and one more thing: it's a so-called fatty alcohol - the good, emollient type of alcohol that is non-drying and non-irritating. It is often mixed with fellow fatty alcohol, Cetyl Alcohol, and the mixture is called Cetearyl Alcohol in the ingredient list.
A common functional ingredient that helps to keep the oil-loving and water-loving ingredients together (emulsifier), stabilizes and thickens the products.
Chemically speaking, it is ethoxylated Cetearyl alcohol, meaning that some ethylene oxide is added to the fatty alcohol to increase the water-soluble part in the molecule. The result is that the mainly oil soluble, emollient fatty alcohol is converted to an emulsifier molecule that keeps oil and water mixed in creams. The number in the name of Ceteareth emulsifiers refers to the average number of ethylene oxide molecules added and 20 makes a good emulsifier.
A so-called fatty (the good, non-drying kind of) alcohol that does all kinds of things in a skincare product: it makes your skin feel smooth and nice (emollient), helps to thicken up products and also helps water and oil to blend (emulsifier). Can be derived from coconut or palm kernel oil.
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.
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".
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.
- It’s the second most researched AHA after glycolic acid
- It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
- It also has amazing skin hydrating properties
- In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
- 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)
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).
The cosmetic's industry is trying to solve the problem by combining avobenzone with other UV filters that enhance its stability (like octocrylene, Tinosorb S or Ensulizole) or by encapsulating it and while both solutions help, neither is perfect. Interestingly, the combination of avobenzone with mineral sunscreens (that is titanium dioxide and zinc oxide) is not a good idea. In the US, it is flat out prohibited as avobenzone becomes unstable when combined with mineral sunscreens.
As for safety, avobenzone has a pretty good safety profile. It counts as non-irritating, and unlike some other chemical sunscreens, it shows no estrogenic effect. The maximum concentration of avobenzone permitted is 5% in the EU and 3% in the US.
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 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.
A silicone fluid that gives a nonoily, easy to spread emolliency to the formulas. It is also used as a water repellent additive and to reduce the tackiness and stickiness of other ingredients. It also imparts gloss, softness and better manageability to hair.
- 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
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".
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 checked Prospector 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 and cheaper 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).
It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range.
Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415).
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.
It is typically used in tiny amounts, around 0.1% or less.
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. Typically used at 1% or less in most formulations.
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!).
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.
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. :))
We don't have description for this ingredient yet.
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.
A common fragrance ingredient that smells like jasmine. It is one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. Best to avoid if your skin is sensitive.
A super common 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 smell nice but the problem is that it oxidizes on air exposure and the resulting stuff is not good for the skin. Oxidized limonene can cause allergic contact dermatitis and counts as a 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.
A common fragrance ingredient that has a nice floral scent and also goes by the name Lilial. It is a known fragrance allergen and as of 1st of March 2022, it has been banned in the EU due to animal studies showing a possible link to infertility (in rats - so no need to panic even if you used a product before with Butylphenyl Methylpropional).
Citronellol is a very common fragrance ingredient with a nice rose-like odor. In the UK, it’s actually the third most often listed perfume on the ingredient lists.
It can be naturally found in geranium oil (about 30%) or rose oil (about 25%).
As with all fragrance ingredients, citronellol can also cause allergic contact dermatitis and should be avoided if you have perfume allergy. In a 2001 worldwide study with 178 people with known sensitization to fragrances citronellol tested positive in 5.6% of the cases.
There is no known anti-aging or positive skin benefits of the ingredient. It’s in our products to make it smell nice.
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 >>
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| what‑it‑does | solvent |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | antioxidant | skin brightening |
| what‑it‑does | skin brightening | antioxidant |
| what‑it‑does | exfoliant | buffering |
| what‑it‑does | sunscreen |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient |
| irritancy, com. | 0, 0 |
| what‑it‑does | sunscreen |
| irritancy, com. | 0, 0 |
| what‑it‑does | moisturizer/humectant | solvent |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient | viscosity controlling | emulsifying | surfactant/cleansing |
| irritancy, com. | 2, 2 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 3, 2 |
| what‑it‑does | emollient | viscosity controlling |
| irritancy, com. | 2, 2 |
| what‑it‑does | emollient | emulsifying |
| irritancy, com. | 0, 1-2 |
| what‑it‑does | surfactant/cleansing | emulsifying |
| irritancy, com. | 0, 0 |
| what‑it‑does | exfoliant | moisturizer/humectant | buffering |
| what‑it‑does | sunscreen |
| what‑it‑does | buffering |
| what‑it‑does | emollient |
| what‑it‑does | exfoliant | anti-acne | soothing | preservative |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | viscosity controlling |
| what‑it‑does | chelating |
| what‑it‑does | viscosity controlling |
| irritancy, com. | 0, 1 |
| what‑it‑does | perfuming |
| what‑it‑does | preservative |
| what‑it‑does | preservative |
| irritancy, com. | 0, 0 |
| what‑it‑does | preservative |
| what‑it‑does | preservative | antimicrobial/antibacterial |
| what‑it‑does | preservative | perfuming |
| irritancy, com. | 0, 0 |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming | solvent |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | preservative |