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.
Cetearyl Alcohol
What-it-does: emollient, viscosity controlling, emulsifying, emulsion stabilising, surfactant/cleansing | 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) tailpart that makes them absolutelynon-drying and non-irritating and are totally ok for the skin.
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 >>
Oleyl Erucate
What-it-does: emollient
A vegetable-basedemollient ester (oleyl alcohol + erucic acid) that makes your skin feel nice and smooth. It has a rich and caring skin feel, very similarto jojoba oil.
Euphorbia Cerifera Cera
What-it-does: astringent, emulsion stabilising, perfuming, viscosity controlling
We don't have description for this ingredient yet.
Vitis Vinifera (Grape) Seed Oil - goodie
Also-called: Grape Seed Oil | What-it-does: antioxidant, emollient
A goodie plant oil coming from the polyphenol-rich seeds of the grape. It's a light emollient oil that makes your skin feel smooth and nice and also contains a bunch of good-for-the-skin stuff. It's a great source of antioxidant polyphenols, barrier repair fatty acid linoleic acid (about 55-77%, while oleic acid is about 12-27%)and antioxidant, skin-protectant vitamin E.
Prunus Amygdalus Dulcis (Sweet Almond) Oil - goodie
Also-called: Sweet Almond Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1-3
The emollient plant oil that comes from almonds. Similar to other plant oils, it is loaded with skin-nourishing fatty acids (oleic acid - 55-86% and linoleic acid 7-35%) and contains several other skin goodies such as antioxidant vitamin E and vitamin B versions.
It's a nice, basic oil that is often used duetoits greatsmoothing, softening and moisturizing properties. It's alsoparticularly good at treating dry brittle nails (source).
Tetradecane
What-it-does: perfuming
We don't have description for this ingredient yet.
Cocos Nucifera (Coconut) Oil - goodie
Also-called: Coconut Oil | What-it-does: emollient, perfuming | Irritancy: 0 | Comedogenicity: 4
There is definitely some craze going on for coconut oil both in the healthy eating space (often claimed to be the healthiest oil to cook with but this is a topic for another site) and in the skin and hair care space.
We will talkhere about the latter two and seewhy we might want to smear it all over ourselves. Chemically speaking, coconutoil has a unique fatty acid profile. Unlike many plant oils that mostly contain unsaturatedfatty acids (fatty acids with double bonds and kinky structure such as linoleic or oleic), coconut oil is mostly saturated (fatty acids with single bonds only) and its most important fatty acid is Lauric Acid(about 50%). Saturated fatty acids have alinear structure that can stack niceand tight and hence they are normally solid at room temperature. Coconut oil melts around 25°C so it is solid in the tub but melts on contact with the skin.
The saturated nature of coconut oil also means that it is a heavy-duty-oil ideal for dry skin types. A double-blind research confirmed that extra virgin coconut oilis as effective in treating xerosis (aka very dry skin) as mineral oil.Another study found that coconut oil is more effective than mineral oil in treatingmild to moderate atopic dermatitis (aka eczema) in children.
So when it comes to dry skin,coconut oil is a goodie, noquestionthere. The question is ifit is good or bad for acne-prone skin. Its main fatty acid, Lauric Acid has some research showing that it is a promising ingredient againstevil acne-causing bacteria, P. acnes but at the same time, both Lauric Acid and coconut oil have a very high comedogenic rating (4 out of 5). Though comedogenic ratings are not very reliable, anecdotal evidence (i.e. people commenting in forums) shows that people havemixed experiences. While some claim that it worked wonders on their acne others say that it gave them serious blackheads and zits. Try it at your own risk.
As for hair care, coconut oil has pretty solid research showing that it can penetrate into the hair very well (better than mineral oil and sunflower oil) and it can prevent hair protein loss as well as combing damage. If you have problems with damaged hair, split ends, coconut oil is worth trying as a pre- or/and post-wash treatment. Labmuffin has an awesome blogpost explaining in more detail why coconut oil is good for your hair.
A couple of other things worth mentioning: coconut oil might help with wound healing (promising animal study), it has some antifungal activity (against dermatophytes that cause the thing known as ringworm) and it also works as an insect repellent against blackflies.
Overall, coconut oil is definitely a goodie for the hair and dry skin. If that warrants for the magic oil status it enjoys, we don't know.
Butyrospermum Parkii (Shea) Butter - goodie
Also-called: Shea Butter | What-it-does: emollient
Unless you live under a rock you must have heard about shea butter. It's probably the most hyped up natural butter in skincare today.It comes from the seeds of African Shea or KariteTreesand used as a magic moisturizer and emollient.
But it's not only a simple emollient, it regenerates and soothes the skin,protects it from external factors (such as UV rays or wind) and is also rich in antioxidants (among others vitamin A, E, F, quercetin and epigallocatechin gallate). If you are looking for rich emollient benefits + more, shea is hard to beat.
Cetearyl Olivate - goodie
Also-called: Part of Olivem 1000 | What-it-does: emulsifying
An ester that comes from Cetearyl alcohol and the fatty acids of olive oil. It oftencomes to the formula coupled with Sorbitan Olivateas the two together form the well-known, naturalemulsifier trade named Olivem 1000.
Other than helping oil and water to blend, the main thing of Olivem 1000 is generating liquid crystal structures that are similar to the lipid structures of the stratum corneum (the outermost layer of the skin). Thanks to this, Olivem 1000 doubles as an active ingredient with significant moisturizing, barrier-repairing and soothing properties.
It also helps to deliver water-soluble actives such as caffeine more effectively, and can even boost SPF in sunscreen formulas. Itstypical use levelis 1-5% and has wide compatibility with other actives and oils.
Overall, areal multi-tasker with nice sensorial properties. No wonderit is so popular.
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.
Stearic Acid
What-it-does: emollient, viscosity controlling | Irritancy: 0 | Comedogenicity: 2-3
A common multi-tasker fatty acid. It makes your skin feel nice and smooth (emollient), gives body to cream type products and helps to stabilize water and oilmixes (aka emulsions).
Sorbitan Olivate - goodie
Also-called: Part of Olivem 1000 | What-it-does: emulsifying
An ester coming from sorbitol and the fatty acids of olive oil. It is part of the popular emulsifier trade named Olivem 1000 that is well-known for generating biomimeticliquid crystal structures. We have more info on Olivem 1000 at Cetearyl Olivate >>
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.
Aloe Barbadensis (Aloe Vera) Leaf Extract - goodie
Also-called: Aloe Leaf Extract | What-it-does: soothing, emollient, moisturizer/humectant
The extract coming from thejuice containing leaves of the Aloe vera plant. It's usually ahydroglycolicextract (though oil extractfor the lipid parts also exists) that has similar moisturizing, emollient and anti-inflammatory properties as the juice itself. We have written some more about aloe here.
Benzyl Alcohol
What-it-does: preservative, perfuming, solvent, viscosity controlling
It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It can be naturally found in fruits and teas but can also be made synthetically.
No matter the origin, in small amounts (up to 1%) it’s a nice, gentle preservative. Has to be combined with some other nice preservatives, like potassium sorbateto be broad spectrum enough.
In high amounts, it can be a skin irritant, but don’t worry, it’s never used in high amounts.
Rubus Idaeus (Raspberry) Seed Oil
Also-called: Raspberry Seed Oil | What-it-does: emollient
We don't have description for this ingredient yet.
Simmondsia Chinensis (Jojoba) Seed Oil - goodie
Also-called: Jojoba Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0-2
Jojoba is a drought resistant evergreen shrub native to South-western North America. It's known and grown for jojoba oil, the golden yellow liquid coming from the seeds (about 50% of the weight of the seeds will be oil).
At first glance, it seems like your average emollient plant oil: it looks like an oil and it's nourishing and moisturizing to the skin but if we dig a bit deeper, it turns out that jojoba oil is really special and unique: technically - or rather chemically - it's not an oil but awax ester (and calling it an oil is kind of sloppy).
So what the heck is a wax ester and why is that important anyway? Well, to understand what a wax ester is, you first have to know that oils are chemically triglycerides:one glycerin + three fatty acids attached to it. The fatty acids attached to the glycerin vary and thus we have many kinds of oils, but they are alltriglycerides. Mother Nature created triglycerides to be easily hydrolyzed (bebroken down to a glycerin + 3 fatty acid molecules) and oxidized (the fatty acid is broken down into small parts) - this happens basically when we eat fats or oils and our body generates energy from it.
Mother Nature also created wax esters but for a totally different purpose. Chemically, a wax ester is a fatty acid + a fatty alcohol, one long molecule. Wax esters are on the outer surface of several plant leaves to give them environmental protection. 25-30% of human sebum is also wax esters to give uspeople environmental protection.
So being a wax ester results in a couple of unique properties: First, jojoba oil is extremely stable. Like crazy stable. Even if you heat it to 370 C (698 F) for 96 hours, it does notbudge. (Many plant oils tend to go off pretty quickly). If you have some pure jojoba oil at home, you should be fine using it for years.
Second, jojoba oil is the most similar to human sebum (both being wax esters), and the two are completely miscible. Acne.org has this not fully proven theory that thanks to this, jojoba might be able to "trick" the skin into thinking it has already produced enough sebum, so it might have "skin balancing" properties for oily skin.
Third, jojoba oil moisturizes the skin through a unique dual action:on the one hand, it mixes with sebum and forms a thin, non-greasy, semi-occlusive layer; on the other hand, it absorbs into the skin through pores and hair follicles thendiffuses into the intercellular spaces of the outer layer of the skin to make it soft and supple.
On balance, the point is this: in contrast to real plant oils, wax esters were designed by Mother Nature to stay on the surface and forma protective, moisturizing barrier and jojoba oil being a wax ester is uniquely excellent at doing that.
Tocopherol (Vitamin E) - 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 >>
Cetearyl Glucoside
What-it-does: emulsifying, surfactant/cleansing
A sugar based emulsifier that's especially great for low viscosity lotions or even sprays. It's effective in small amounts, only 1-1.5% is needed to form an emulsion. The resulting cream or lotion has great cosmetic properties with good spreadability and an enhanced soft skin feel.
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!).
Lecithin - goodie
What-it-does: emollient, emulsifying
A very common ingredient that can be found inall 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.
Argania Spinosa Kernel (Argan) Oil - goodie
Also-called: Argan Oil | What-it-does: antioxidant, emollient
When it comes to cosmetic oils and hype, argan oil is for sure leading the way. Dubbed as the "liquid gold of Morocco", we have to admit we have some trouble determining why this oil enjoys such a special miracle status. Not that it's not good, it is good, even greatbut reading the research about argan and a bunch of other plant oils we just do not see the big, unique differentiating factor (though that might be our fault not reading enough, obvs.)
So, argan oil comes from the kernel of the argan fruit that comes from the argan tree that grows only in Morocco. The tree is slow growingand getting the oil is a hard job. The traditional process is that the ripe argan fruits fallfrom the tree, then goats eat them up and poop out the seeds. The seedsare collected and smashed with a stone to get the kernels inside. This part is the hard one as the seeds have extremely hard shells. Once the kernels are obtained, the oil is pressed out from them (the kernels contain about 50% oil).
As for skincare, argan oil is loaded with lots of skin goodies (but so are many other plant oils): it contains 80% nourishing and moisturizing unsaturatedfatty acids, mainly oleic (38-50%), linoleic (28-38%) and palmitic (10-18%). It also contains a relatively large amount of antioxidant vitamin E (600-900 mg/kg, about twice as much as olive), small amounts of antioxidant phenols (including caffeic acid, ferulic acid, and epicatechin), as well as some rare sterols with soothing and anti-inflammatory properties.
Thanks to all the above goodness in argan oil, it can greatly nourish and moisturize the skin and hair. It's also claimed to be able to neutralize collagen-damaging free radicals, help reduce scars, and revitalize and improve skin elasticity. You can even read that argan might help acne-prone skin, but being a high oleic oil, we would be careful with that.
All in all, argan oil is a real goodie but we do not fully understand the special miracle status it enjoys.
Panthenol (Vitamin B5) - 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.
Nelumbo Nucifera (Lotus) Flower Oil
We don't have description for this ingredient yet.
Cetyl Palmitate
What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0
A white, waxy emollient that gives "body" to skincare formulas. Comes from coconutor palm kernel oil.
Faex Extract - goodie
What-it-does: moisturizer/humectant
You probably know yeast from the kitchen where you put it into milk with a little sugar and then after a couple of minutes brownish bubbles form. That is the fungi fermenting the sugar.
As for skin care, yeast contains beta-glucanthat is a great soothing ingredient and also a mild antioxidant. The yeast extract itself is a silky clear liquid that has some great moisturizing, skin protecting and film-forming properties on the skin.
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.
Chondrus Crispus Powder
What-it-does: abrasive/scrub
We don't have description for this ingredient yet.
Salicylic Acid - superstar
Also-called: BHA | What-it-does: exfoliant, anti-acne, soothing, 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
Read all the geeky details about Salicylic Acid here >>
Cucumis Sativus (Cucumber) Fruit Extract - goodie
Also-called: Cucumber Fruit Extract | What-it-does: soothing, emollient
Cucumber is a nice, non-irritating plant extract that’s known for it’s soothing and emollient properties. It’s not something new to put it on our face: even Cleopatra used it to “preserve her skin”.
It’s commonly believed that cucumber is the answer to puffy eyes, but there is no research confirming this. What research does confirm is that it contains amino acids and organic acids that’s helpful for the skin’s acid mantle. There is also an enzyme (called shikimate dehydrigenase) in the pulp that’s shown to have anti-inflammatory properties.
Vanilla Planifolia Fruit Extract
We don't have description for this ingredient yet.
Algin
Also-called: Sodium Alginate | What-it-does: viscosity controlling | Irritancy: 4 | Comedogenicity: 4
A large sugarmolecule (aka polysaccharide) that's used as a gelling agent and comes from brown seaweed.
Combined with calcium salts, it forms a rigid gel used in "rubber masks".
Diethyl Succinate
What-it-does: solvent
We don't have description for this ingredient yet.
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.
Pelargonium Roseum Leaf Oil
What-it-does: perfuming
We don't have description for this ingredient yet.
Potassium Carbonate
What-it-does: buffering
We don't have description for this ingredient yet.
Sorbic Acid
What-it-does: preservative
A mild, natural preservative that usually comes to the formula together with its other mild preservative friends, such as Benzoic Acid and/orDehydroaceticAcid. Btw, it's also used as a food preservative.
Retinyl Palmitate
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 king being the FDA-approved anti-aging ingredient tretinoin. Retinol is also a very famous member of the family, but it's like Prince George,two steps away from the throne. Retinyl palmitate will be thenPrince Charlotte(George's little sister), quite far (3 steps) awayfrom 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:
retinyl palmitate --> retinol -- > retinaldehyde --> all-trans-retinoic acid
As we wrote in our lengthy retinol description the problem is that the conversion is not terriblyeffective. 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 Dermatologybook writes that RP is topically ineffective.
What's more, the anti-aging effectiveness is not the only questionable thing about RP. It also exibitsquestionable 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 bySteven 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 palmitatehere. It seems that there is a study showing RP being photo protective against UVB rays but there is also a study showingRP 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 addespeciallyduring 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.
Caprylic/Capric Triglyceride
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, is super well tolerated by every skin type andeasy to formulate with. No wonder it’s popular.
Ginkgo Biloba Leaf Extract
Also-called: Ginkgo Biloba Extract
We don't have description for this ingredient yet.
Hyaluronic Acid - goodie
What-it-does: skin-identical ingredient, moisturizer/humectant
- It’s naturally in our skin and behaves there like a sponge
- It can bind up to 1000 times its own weight in water
- It is a big molecule from repeated subunits (polymer) so different molecular weight versions exist (unfortunately there is no way to determine MW from INCI list only)
- High-molecular-weight-HA (>500 kDa) is an excellent surface hydrator, skin protectant and can act as an osmotic pump helping water-soluble actives to penetrate deeper into the skin
- Low-molecular-weight-HA (< 500 kDa) can hydrate the skin somewhat deeper though it is still a big molecule and works mainly in the epidermis (outer layer of the skin)
- Low-molecular-weight-HA might also help the skin to repair itself by increasing its self-defense (~ 200kDa used in the study)
- Ultra-low-molecular-weight-HA (<50kDa) is a controversial ingredient and might work as a pro-inflammatory signal molecule
Read all the geeky details about Hyaluronic Acid here >>
Panax Ginseng Root Extract - goodie
Also-called: True Ginseng, Ginseng, Korean Ginseng | What-it-does: antioxidant, emollient
Atraditional Korean medicine used for more than2000 years. Regarding skin care, its main thing seems to be enhancing skin nutrition and metabolism as a result of improvingblood circulation.
It also contains biologically active components referred to as ginseng saponins (ginsenosides) that have potent antioxidant properties.
Sodium Benzoate
What-it-does: preservative
A helper ingredient that helps to makethe 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.
Potassium Sorbate
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.
BTW, it’s also a food preservativeand even has an E number, E202.
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.
Citronellol - icky
What-it-does: perfuming
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.
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.
