Kateceuticals Resurfacing Overnight Peel
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Kate Somerville Kateceuticals Resurfacing Overnight PeelIngredients 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.
- 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 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 and easy to formulate with. No wonder it’s popular.
An extremely common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams and lotions. It also helps to stabilize oil-water mixes (emulsions), though it does not function as an emulsifier in itself. Its typical use level in most cream type formulas is 2-3%.
It’s a so-called fatty alcohol, a mix of cetyl and stearyl alcohol, other two emollient fatty alcohols. Though chemically speaking, it is alcohol (as in, it has an -OH group in its molecule), its properties are totally different from the properties of low molecular weight or drying alcohols such as denat. alcohol. Fatty alcohols have a long oil-soluble (and thus emollient) tail part that makes them absolutely non-drying and non-irritating and are totally ok for the skin.
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 clear, odorless, very light emollient ester that helps to achieve light textures. It has great spreadability, a good slip, and a silky skin feel. It's ideal to solubilize sunscreen agents and fragrances. It's also touted as a volatile (evaporates from the skin rather than absorbs into it) silicone alternative, especially to replace Cyclomethicone mixes.
Propanediol is a natural alternative for the often used and often bad-mouthed propylene glycol. It's produced sustainably from corn sugar and it's Ecocert approved.
It's quite a multi-tasker: can be used to improve skin moisturization, as a solvent, to boost preservative efficacy or to influence the sensory properties of the end formula.
- 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
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 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
We don't have description for this ingredient yet.
A common water-loving surfactant and emulsifier that helps to keep water and oil mixed nicely together.
A spherical texturizing powder that's used as a texture enhancer and soft focus agent. It's claimed to give silicone type softness to the formula and also works as a (temporary) wrinkle filler.
- Retinol (pure Vitamin A) is probably the most proven anti-aging ingredient available OTC
- It has to be converted in the skin to retinoic acid to work its magic
- Once converted, it has the same effect as all-trans-retinoic acid, aka tretinoin
- A generally accepted ballpark number is that retinol is 10-to-20 times less potent than retinoic acid
- It makes skin less wrinkled, smoother, firmer and tighter
- It might also be helpful for acne prone skin as it normalizes keratinization and makes the pores produce less sebum
- Possible side effects and irritation are also much less than with retinoic acid
- Do not use whilst pregnant
The extract of Prickly Pear, a cactus that’s native to Mexico. Its main unique thing is that it can reduce the neurosensory irritation caused by the application of topical products such as retinoids (slow reaction) or alpha hydroxy acids (fast reaction). We have a shiny description about Opuntia Ficus-Indica Extract here >>
Hydrolyzed Hyaluronic Acid is a low molecular weight, chemically chopped up version of the naturally big molecule and current IT-moisturizer, Hyaluronic Acid (HA). 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 retain water, making it plump and elastic. As HA is a polymer, the subunits can be repeated many times (as a high-molecular-weight version), or just a few times (as a low-molecular-weight version).
We wrote in detail at HA about how different molecular weight versions do different things both as a component of the skin and as a skincare ingredient, so click here and read about all the details. Hydrolyzed Hyaluronic Acid can also come in different molecular-weight versions with different properties:
- 100-300 kDa version: apart from moisturizing, this size might also help the skin to repair itself by increasing its self-defense. It is also claimed to boost the wound healing process and is especially helpful for sensitive skin types (acne, rosacea, inflammation-related skin diseases).
- 50k Da version: this is the size that is claimed to be able to absorb into the skin and plump up wrinkles, so it is used mainly as an "anti-aging ingredient"
- below 50k, around 10k Da version: there is a Japanese version trade named Hyalo-Oligo that has only a 10k molecular weight and is claimed to penetrate the skin very well, have a unique touch and give deep and long-lasting moisturization. Based on the Evonik-research and the natural role of LMW-HA in the body working as a pro-inflammatory signal molecule, this ultra-low molecular weight version is a controversial ingredient.
If you wanna become a real HA-and-the-skin expert, you can read much 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 a helper ingredient that helps to thicken up formulas and form a nice gel texture. It leaves a rich, elegant feel with a velvety finish on the skin and works over a wide pH range.
You might know licorice as a sweet treat from your childhood, but it's actually a legume that grows around the Mediterranean Sea, the Middle East, central and southern Russia. It's sweet and yellow and not only used for licorice all sorts but it's also a skincare superstar thanks to two magic properties:
Nr. 1 magic property is that it has skin-lightening or to say it another way depigmenting properties. The most active part is called glabridin. The topical application (meaning when you put it on your face) of 0.5% glabridin was shown to inhibit UVB caused pigmentation of guinea pigs. Another study even suggested that licorice is more effective than the gold standard skin-lightening agent hydroquinone. All in all, licorice is considered to be one of the safest skin lightening agents with the fewest side effects.
There is just one catch regarding glabridin and licorice: the amount of glabridin in commercial licorice extracts can vary a lot. We have seen extracts with only 4% glabridin as well as 40% glabridin. The latter one is a very-very expensive ingredient, so if you are after the depigmenting properties try to choose a product that boasts its high-quality licorice extract.
Nr. 2 magic property is that licorice is a potent anti-inflammatory. Glabridin has also some soothing properties but the main active anti-inflammatory component is glycyrrhizin. It’s used to treat several skin diseases that are connected to inflammation including atopic dermatitis, rosacea or eczema.
Oh, and one more thing: glabridin seems to be also an antioxidant, which is just one more reason to be happy about licorice root extract on an ingredient list.
Bottom line: Licorice is a great skincare ingredient with significant depigmenting, anti-inflammatory and even some antioxidant properties. Be happy if it's on the ingredient list. :)
A white, waxy emollient that gives "body" to skincare formulas. Comes from coconut or palm kernel oil.
Adenosine is an important little compound in our body that has a vital cell-signalling role. Research on smearing it on our face is also promising and shows so far a couple of things:
- It can help with wound healing
- It’s a good anti-inflammatory agent
- It might even help with skin’s own collagen production and improve skin firmness and elasticity
- It helps with barrier repair and protection
- It might be even useful for the hair helping with hair thickness and hair growth
One of the many types of ceramides that can be found naturally in the upper layer of the skin. Ceramides make up about 50% of the goopy stuff that's between our skin cells and play a super important role in having a healthy skin barrier and keeping the skin hydrated. It works even better when combined with its pal, Ceramide 1.
We wrote way more about ceramides at ceramide 1, so click here to know more.
We don't have description for this ingredient yet.
It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula.
We don't have description for this ingredient yet.
Saccharomyces cerevisiae (SC) is the fancy name for common baker’s yeast.
Usually different kind of yeast extracts are used in skincare for their great hydrating, and general skin conditioning properties. We could find one research paper to back this up: It has found that SC indeed increases skin moisture and had improved skin microrelief (the small wrinkles and surface irregularities of skin).
According to manufacturer info coupled with the Mexican cactus, prickly pear it also helps to reduce neurosensory irritation that might occur from potent retinol or AHA products.
A 100% natural and plant-derived moisturizer that mimics the natural carbohydrate fraction found in the upper layer of the skin. Its special magic power is to bind to the skin stronger and longer than other moisturizer ingredients do so it can keep the skin hydrated longer than usual.
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.
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.
As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types).
We don't have description for this ingredient yet.
A white waxy solid that helps water and oil to mix nicely together (emulsifier). It is derived from the fatty alcohol lauryl alcohol by ethoxylating it and thus making the molecule a lot more water-soluble. In fact, Laureth-23 is mostly water-soluble acting as a solubilizer for dissolving small amounts of oily things into water-based formulas.
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.
We don't have description for this ingredient yet.
A clear liquid with a camphor-like odor that is used as a solvent.
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 preservative and even has an E number, E202.
A helper ingredient that helps to make the products stay nice longer, aka preservative. It works mainly against fungi.
It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.
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.
If you have spotted ethylhexylglycerin on the ingredient list, most probably you will see there also the current IT-preservative, phenoxyethanol. They are good friends because ethylhexylglycerin can 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 spreading emollient.
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 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).
A type of clay mineral that works as a nice helper ingredient to thicken and stabilize formulas. As a clay, it consists of platelets that have a negative charge on the surface (face) and a positive on the edge. So the face of one platelet attracts the edge of the other and this builds a so-called "house of card" structure meaning that Magnesium Aluminum Silicate (MAS) thickens up products and helps to suspend non-soluble particles such as color pigments or inorganic sunscreens (zinc oxide and titanium dioxide).
As the "house of card" structure takes some time to form but collapses quickly if the formula is stirred, products thickened with MAS can be thick in the jar but become easily spreadable upon application (called thixotropy). MAS also gives nice sensory properties, it is not tacky or sticky and gives a rich, creamy skin feel. Also a good team player and works in synergy with other thickeners such as Cellulose Gum or Xanthan Gum.
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.
It’s a common fragrance ingredient that has a light floral smell. 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.
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.
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 limonene it 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.
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| what‑it‑does | solvent |
| what‑it‑does | exfoliant | buffering |
| what‑it‑does | moisturizer/humectant |
| what‑it‑does | emollient |
| what‑it‑does | emollient | viscosity controlling | emulsifying | surfactant/cleansing |
| irritancy, com. | 1, 2 |
| what‑it‑does | buffering |
| what‑it‑does | emollient |
| what‑it‑does | solvent | moisturizer/humectant |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient | emulsifying |
| irritancy, com. | 0, 1 |
| what‑it‑does | cell-communicating ingredient | skin brightening | anti-acne | moisturizer/humectant |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | soothing | moisturizer/humectant |
| what‑it‑does | moisturizer/humectant |
| what‑it‑does | viscosity controlling |
| what‑it‑does | soothing | skin brightening |
| what‑it‑does | emollient |
| irritancy, com. | 0, 0 |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | skin-identical ingredient |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 0, 0 |
| what‑it‑does | moisturizer/humectant |
| what‑it‑does | moisturizer/humectant |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 3, 2 |
| what‑it‑does | emollient |
| irritancy, com. | 0, 1 |
| what‑it‑does | skin brightening |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 0, 3 |
| what‑it‑does | antioxidant |
| irritancy, com. | 0, 0 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | perfuming | solvent |
| what‑it‑does | preservative |
| what‑it‑does | preservative |
| what‑it‑does | chelating |
| what‑it‑does | preservative |
| what‑it‑does | perfuming |
| what‑it‑does | viscosity controlling |
| what‑it‑does | viscosity controlling |
| irritancy, com. | 0, 0 |
| what‑it‑does | preservative |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming |
| what‑it‑does | perfuming | solvent |
| what‑it‑does | perfuming |