Clinical 1% Retinol Treatment
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Paula's Choice Clinical 1% Retinol TreatmentIngredients 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.
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).
- 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
Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.
BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.
It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive.
An emollient ester with a rich and creamy but non-greasy skin feel. It makes skin supple and protects dry skin.
We don't have description for this ingredient yet.
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".
An often used emollient with a light and silky feel. It's very mild to both skin and eyes and spreads nicely and easily. It's often used in sunscreens as it's also an excellent solvent for sunscreen agents.
A high-molecular-weight silicone elastomer (rubber-like elastic material) that is usually blended with a base silicone fluid (such as dimethicone or cyclopentasiloxane) to give the formula a silky smooth feel and to act as a thickening agent.
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.
A fatty alcohol (the non-drying type with a long oil loving chain of 22 carbon atoms) that is used to increase the viscosity of the formula and it also helps the oily and the watery parts to stay nicely mixed together (called emulsion stabilizing).
- 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
Tetrahexyldecyl Ascorbate is a stable, oil-soluble form of skincare big shot Vitamin C. If you do not know, why Vitamin C is such a big deal in skincare, click here and read all about it. We are massive vitamin C fans and have written about it in excruciating detail.
So now, you know that Vitamin C is great and all, but it's really unstable and gives cosmetics companies many headaches. To solve this problem they came up with vitamin C derivatives, and one of them is Tetrahexyldecyl Ascorbate (let's call it THDA in short).
It's a really promising candidate (see below), but while reading all the goodness about it in a minute, do not forget that derivatives not only have to be absorbed into the skin but also have to be converted to pure vitamin C (ascorbic acid or AA) and the efficacy of the conversion is often unknown. In addition, vitamin C's three magic properties (antioxidant, collagen booster, skin brightener) are all properly proven in-vivo (on real people), but for the derivatives, it's mostly in-vitro studies or in the case of THDA, it's in-vitro and done by an ingredient supplier.
With this context in mind let's see what THDA might be able to do. First, it is stable (if pH < 5), easy to formulate, and a joy to work with for a cosmetic chemist.
Second, because it's oil-soluble, its skin penetration abilities seem to be great. So great in fact, that it surpasses the penetration of pure vitamin C threefold at the same concentration and it penetrates successfully into the deeper layers of the skin (that is usually important to do some anti-aging work). There is also in-vitro data showing that it converts to AA in the skin.
Third, THDA seems to have all three magic abilities of pure vitamin C: it gives antioxidant protection from both UVB and UVA rays, it increases collagen synthesis (even more than AA) and it has a skin brightening effect by reducing melanogenesis by more than 80% in human melanoma cell cultures.
So this all sounds really great, but these are only in-vitro results at this point. We could find Tetrahexyldecyl Ascorbate mentioned only in one published in-vivo study that examined the anti-aging properties of a silicone formula containing 10% AA and 7% THDA. The authors theorized that the 10% AA is released slowly from the silicon delivery system and probably stays in the upper layer of the skin to give antioxidant benefits, while THDA penetrates more rapidly and deeply and gives some wrinkle-reducing benefits. The study was a small (10 patients), double-blind experiment, and the formula did show some measurable anti-aging results. However, it is hard to know how much pure vitamin C or THDA can be thanked.
Bottom line: a really promising, but not well-proven vitamin C derivative that can be worth a try especially if you like experimenting (but if you like the tried and true, pure vitamin C will be your best bet).
One of the 9 types of ceramides that can be found naturally in the upper layer of the skin. Ceramides make up a big part (about 50%) of the goopy stuff that's between our skin cells (called extracellular matrix) and play a super important role in having a healthy skin barrier and keeping the skin hydrated.
We wrote way more about ceramides at ceramide 1, so click here to know more.
A six amino acid peptide that is claimed to improve firmness and skin tone. Its amino acid sequence is Val-Gly-Val-Ala-Pro-Gly that is also called the "spring fragment" and is repeated six times in the important skin protein, elastin molecule.
The manufacturer made a double-blind, one-month long clinical study on 10 women and found that twice a day application of 4% Biopeptide El improved skin firmness by 33% and skin tone by 20%.
A four amino acid peptide with the amino sequence of glycine-glutamine-proline-arginine. It is attached to palmitic acid (a fatty acid) to increase oil solubility and skin penetration.
It works by reducing the production of the signal molecule, interleukin-6 (IL-6) which promotes inflammation in the skin and less inflammation means slower degradation of important things (like collagen) that results in younger looking skin for a longer time.
It works in synergy with its pal, Palmitoyl Tripeptide-1 in the famous Matrixyl 3000 complex. You can read some more about the famous duo here.
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).
The salt form of one of the main anti-inflammatory ingredients in the licorice plant, monoammonium glycyrrhizinate. It’s a yellowish powder with a nice sweet smell.
It’s used mainly for its soothing and anti-inflammatory properties, but according to manufacturer info, it’s also sebum regulating so it's a perfect ingredient for problem skin products.
Read more about licorice and why it's a skincare superstar here.
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. :)
When you hear oatmeal, you probably think of breakfast, but the finely ground version of whole oat kernels, aka colloidal oatmeal, can do good things for your skin, especially if it's dry, itchy or prone to skin-rashes or eczema.
Oat is loaded with compounds good for the body, inside or outside, such as soothing agent beta-glucan (5%), lipids (3-11%) including barrier repairing omega-3 and 6 fatty acids or phenolic antioxidant and anti-inflammatory agents (avenanthramides).
The soothing, antioxidant and skin-protecting abilities of oat are so well-established that it is an active natural ingredient covered by the FDA OTC Skin Protectant monograph in the US, meaning that colloidal oatmeal can be claimed as an active ingredient on the INCI list and Aveeno is a mass-market brand built around oat-containing products.
If your skin is dry, irritated, inflamed or eczema-prone, colloidal oatmeal is something to try.
Burdock root is a goodie plant extract that has anti-inflammatory and antioxidant properties. Also, it has some anti-fungal and seborrhea regulation magic powers that make the ingredient especially useful for greasy and flaky skin and scalp.
The extract coming from the bark of the White Willow, a big (25 m/80 ft.) tree that likes to live on riverbanks. It's famous for containing anti-inflammatory natural salicylates (this powder, for example, is standardized to contain 53-65%), a close chemical relative to famous exfoliant salicylic acid.
Thanks to its salicin content, willow bark is often touted as a natural alternative to salicylic acid, though it's quite questionable how effective it is as a chemical exfoliant in the tiny amounts used in cosmetics. Apart from soothing salicin, it also contains flavonoids and phenolic acids that give willow bark tonic, astringent, and antiseptic properties.
We don't have description for this ingredient yet.
A very common ingredient that can be found in all cell membranes. In cosmetics it's quite the multi-tasker: it's an emollient and water-binding ingredient but it's also an emulsifier and can be used for stabilization purposes. It's also often used to create liposomes.
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 cosmetic products is produced synthetically.
It's not only soothing but it' also skin-softening and protecting and can promote wound healing.
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.
An ingredient that helps water and oil to mix together, aka emulsifier. Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the fatty acid Lauric Acid, that creates a partly water (the sorbitan part) and partly oil soluble (lauric part) molecule.
Sorbitan Laurate is a good team player that likes to work with many other emulsifiers and is compatible with a wide range of other ingredients.
A soothing dipeptide (tyrosine + arginine) based molecule that functions as a "messenger of tranquility and muscle relaxation". It works via stimulating the skin nerve cells to release met-enkephalin, which is an opioid (i.e. relaxing, pain-relieving) messenger molecule.
This means that Acetyl Dipeptide-1 Cetyl Ester can "signal" our skin cells to "relax" and it can instantly decrease skin irritations coming from heat, chemical stinging or mechanical stresses. It is also claimed to be able to prevent the onset of wrinkles and expression lines thanks to its muscle relaxation properties.
Regarding the research, we could find one study that compared the calming effects of our guy with the soothing molecule called 4-T-Butylcyclohexanol. They irritated the skin with Capsaicin (the active in chili peppers) and examined how the test products relieved the burning/stinging sensation. They found that both molecules worked, but 4-t-Butylcyclohexanol worked somewhat better.
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 nice little helper ingredient that can thicken up cosmetic products and create beautiful gel formulas. It's derived from cellulose, the major component of the cell wall of green plants. It is compatible with most co-ingredients and gives a very good slip to the formulas.
The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right.
For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.
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.
It's the triglyceride of behenic acid that works as a thickening or gelling agent, as a compacting agent for pressed powders, and improves heat stability of emulsions.
It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol.
The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.
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.
A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as an emulsion stabilizer, solvent and a broad spectrum antimicrobial. According to manufacturer info, it's also a moisturizer and helps to make the product feel great on the skin. It works synergistically with preservatives and helps to improve water-resistance of sunscreens.
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.
We don't have description for this ingredient yet.
A water-soluble silicone (silicones are normally oil soluble) that makes your skin nice and smooth (aka emollient) and improves cushion, texture, and slip in the formula.
We don't have description for this ingredient yet.
A liquid emollient derived from isostearic acid that gives a rich, cushiony skin-feel and unusually high levels of gloss. It also has film-forming abilities but without leaving a sticky residue and it aids long-lasting and water-resistant properties. All this makes Pentaerythrityl Tetraisostearate an ideal emollient for long-lasting protective emulsions, like lip balms.
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.
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.
An ingredient that is created from the attachment of the water-loving sugar molecule, glucose, and an oil-loving 20 carbon long fatty chain. This makes it a partly water- and partly oil-soluble material, meaning it functions as an emulsifier helping oil and water to mix.
Most often, it comes to the formula coupled with two fatty alcohol friends, Arachidyl and Behenyl alcohol, to make up an emulsifier trio trade named Montanov 202. As described by its manufacturer, the main thing of Montanonv 202 is that it gives creams a unique evanescent and light feel with a matt finish. It also leaves the skin soft, but not oily, is hypoallergenic and non-comedogenic making it perfect for both oily and sensitive skin formulas.
A big sugar molecule (polysaccharide) that is used as a natural thickening and gelling agent. It is similar to more commonly used Xanthan Gum, and the two are also often combined to create gel formulas or to stabilize emulsions.
A fatty alcohol (the non-drying type with a long oil loving chain of 20 carbon atoms) that is used to increase the viscosity of the formula and it also helps the oily and the watery parts to stay nicely mixed together (called emulsion stabilizing).
An Ecocert-approved, natural preservative that counts as gentle and non-irritating to the skin. Usually, it comes to the formula as part of a preservative blend as it's not enough on its own.
A pre-neutralised form of super common thickener, Carbomer. This means that it forms viscous gels immediately upon addition to water (while Carbomer has to be neutralized with a base), but it can also be harder to disperse evenly in the formula.
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.
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| what‑it‑does | solvent |
| what‑it‑does | emollient |
| irritancy, com. | 0, 1 |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | moisturizer/humectant | solvent |
| irritancy, com. | 0, 1 |
| what‑it‑does | emollient |
| what‑it‑does | emollient | emulsifying |
| irritancy, com. | 0, 1 |
| what‑it‑does | emollient | antimicrobial/antibacterial |
| what‑it‑does | viscosity controlling |
| what‑it‑does | moisturizer/humectant | solvent |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient | viscosity controlling |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | antioxidant | skin brightening |
| what‑it‑does | skin-identical ingredient |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | soothing | moisturizer/humectant |
| what‑it‑does | soothing | skin brightening |
| what‑it‑does | antioxidant | soothing | emollient | abrasive/scrub |
| what‑it‑does | antioxidant | soothing |
| what‑it‑does | soothing |
| what‑it‑does | emollient |
| what‑it‑does | emollient | emulsifying |
| what‑it‑does | soothing |
| irritancy, com. | 0, 0 |
| what‑it‑does | antioxidant |
| irritancy, com. | 0, 0 |
| what‑it‑does | moisturizer/humectant |
| what‑it‑does | emulsifying |
| irritancy, com. | 1-2, 1-2 |
| what‑it‑does | cell-communicating ingredient | soothing |
| what‑it‑does | chelating |
| what‑it‑does | viscosity controlling |
| what‑it‑does | buffering |
| what‑it‑does | emollient |
| what‑it‑does | moisturizer/humectant | emollient |
| what‑it‑does | preservative |
| what‑it‑does | solvent | moisturizer/humectant |
| what‑it‑does | surfactant/cleansing | emulsifying |
| irritancy, com. | 0, 0 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | emollient |
| what‑it‑does | emulsifying |
| what‑it‑does | emollient |
| what‑it‑does | moisturizer/humectant | solvent |
| what‑it‑does | emollient | emulsifying | surfactant/cleansing |
| irritancy, com. | 0, 2 |
| what‑it‑does | viscosity controlling |
| irritancy, com. | 0, 0 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | viscosity controlling |
| what‑it‑does | emollient | viscosity controlling |
| what‑it‑does | preservative |
| what‑it‑does | viscosity controlling |
| what‑it‑does | preservative |