Starter Retinol Serum
Ingredients overview
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Key Ingredients
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The Inkey List Starter Retinol SerumIngredients 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
A clear, colorless, almost odorless oil that spreads nicely and easily and gives a velvet dry skin feel. It is good friends with sunscreen agents and helps to solubilize them. Also, it makes sunscreens feel lighter and spread easier.
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 emulsifier that helps oil and water to nicely mix together. It is claimed to bring a silicone-feel to natural formulations and to give an ultra-soft texture and cushion touch.
It is a natural wax derivative (from rice bran, candelilla, and jojoba waxes) that also has some moisturizing properties as it can retain 6 times its own weight in water, forming a water cushion on the 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 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.
We don't have description for this ingredient yet.
The combination of glycerin + behenic acid that comes either in a fine powder or waxy solid form. Together with the di- and triglyceride of behenic acid, the trio has remarkable gelling properties helping cosmetic chemists to create ultra-soft and non-tacky waterfree gels. They also have great emulsion stabilizing properties, and work as high-performance compacting agents for makeup products that come in the form of pressed powders.
It's also vegetable origin, and Ecocert certified.
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.
This long-named, polymer molecule (big molecule from repeated subunits) is a helper ingredient that's good at emulsifying and stabilizing oils into water-based formulas. It also acts as a thickening and gelling agent that creates nice, non-sticky and supple textures. It works over a very wide pH range (3-12) and can be used to thicken up low-ph formulas, such as exfoliants. Its recommended used range is 0.3-3%.
We don't have description for this ingredient yet.
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.
It seems to us that squalane is in fashion and there is a reason for it. Chemically speaking, it is a saturated (no double bonds) hydrocarbon (a molecule consisting only of carbon and hydrogen), meaning that it's a nice and stable oily liquid with a long shelf life.
It occurs naturally in certain fish and plant oils (e.g. olive), and in the sebum (the oily stuff our skin produces) of the human skin. As f.c. puts it in his awesome blog post, squalane's main things are "emolliency, surface occlusion, and TEWL prevention all with extreme cosmetic elegance". In other words, it's a superb moisturizer that makes your skin nice and smooth, without being heavy or greasy.
Another advantage of squalane is that it is pretty much compatible with all skin types and skin conditions. It is excellent for acne-prone skin and safe to use even if you have fungi-related skin issues, like seborrhea or fungal acne.
The unsaturated (with double bonds) and hence less stable version of Squalane is Squalene, you can read about it here >>
A type of lipid that's the major (about 75%) component of all cell membranes. As for skincare, it works as an emollient and skin-identical ingredient.
It has a water-loving head with two water-hating tails and this structure gives the molecule emulsifying properties. It is also often used to create liposomes, small spheres surrounded by phospholipid bi-layer designed to carry some active ingredient and help its absorption.
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).
It's one of the active parts of Chamomile that contains about 30% of bisabolol. It's a clear oily fluid that is used in skincare as a nice anti-inflammatory and soothing ingredient.
The emollient plant oil coming from the soybean. It is considered to be a nice, cost-effective base oil with moisturizing properties. As for its fatty acid profile, it contains 48-59% barrier-repairing linoleic acid, 17-30% nourishing oleic acid and also some (4.5-11%) potentially anti-inflammatory linolenic acid.
A common little helper ingredient that helps water and oil to mix together, aka emulsifier.
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.
It’s one of those little helper ingredients that makes sure the product stays the same over time. No color change or anything like that. 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.
Hydroxypinacolone Retinoate (HPR) is the newest member of the "royal family of skincare" (see who is who on this cool retinoids family tree), the retinoid family. The queen of the family is the FDA-approved anti-aging superstar, retinoic acid, aka tretinoin and HPR seems to be a gentle but influential sister princess to the queen.
Good to know: the trade name of HPR is Granactive Retinoid. The manufacturer produces it as 10% active and 90% solvent called dimethyl isosorbide. When a product claims 2% Granactive Retinoid, it means 0.2% Hydroxypinacolone Retinoate (and 1.8% dimethyl isosorbide) on the ingredient list.
It's a so-called retinoic acid ester, meaning that it's directly related to retinoic acid. If you've already read our description about retinol or retinyl palmitate, you know that the active ingredient our skin cells can interpret is retinoic acid. Other forms of retinoids have to be converted by our metabolic machinery to do something. That's not the case with HPR. It binds directly to the retinoid receptors of the skin cells to work its skincare magic.
The big promise of HPR is that it's similarly active as retinoic acid (no conversion needed, remember) but without the irritation. According to the manufacturer's tests, 24 hours of an occlusive patch with 0.5% HPR resulted in significantly lower irritation than 0.5% retinol. Also, there was a "dramatic reduction of lines and wrinkles" after applying 0.2% HPR around the eyes twice a day for 14 days.
These results sound sooo promising that we don't blame you if you wanna run out right now and get an HPR formula to slather on your face. But, before you do, you have to know that the info we have about HPR at the moment is mainly from the manufacturer, whose tests may or may not be accurate or properly designed (such as controlled, double-blind and conducted on an appropriate number of people).
As HPR is pretty new there isn't that much independent research we could find yet. We found two Italian studies both examining the efficacy of HPR combined with other things (retinol in both cases, and papain in one of them) for the treatment of acne. Both studies found the formulas effective but they contained other things too, so it's hard to judge how well HPR did.
Regarding anti-aging, there is a pretty recent, Estee Lauder sponsored study that compared the in-vitro (not on real human beings but on skin models) collagen-boosting effectiveness of Hydroxypinacolone Retinoate, tretinoin, good old retinol and retinyl palmitate (RP). The results are pretty encouraging showing that "HPR had greater levels of gene transcription than retinol and RP (RP) at the same concentrations ... however, HPR did not achieve gene transcription levels of ATRA (tretinoin)." But, a much higher dose might be tolerated from HPR and the highest dose of HPR out-performed tretinoin. Pretty encouraging, though we are very much waiting for a study to confirm all this on real human beings.
Bottom line: We are really happy to see some innovation happening with retinoids, and we think Hydroxypinacolone Retinoate is a super promising rising star, but it’s not fully proven yet. If you are someone who likes to experiment and try out the newest things, grab your running shoes and try some HPR containing serum now (see product list below :)). If you like the tried and true, however, stick to retinol and tretinoin for now and re-examine the question in a couple of years when (hopefully) more research will be available.
Are you into Retinoids? Read our shiny description about other members of the retinoid family:
- Retinyl Propionate: the most promising retinol ester out there
- Retinyl Retinoate: a super interesting retinol-retinoic acid hybrid molecule
- Tretinoin: the FDA-proven, well-known active ingredient
- Retinol: the good old vitamin A molecule
- Retinyl Palmitate: a super common, but our least fav member of the retinoids
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.
We don't have description for this ingredient yet.
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 months and 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.
A handy helper ingredient that helps water and oil to mix nicely together, aka emulsifier. It is especially recommended for protective, baby care and general purpose emollient creams.
It also helps to disperse insoluble particles (think color pigments or zinc/titanium dioxide sunscreen) nice and even in cosmetic formulas.
A common little helper ingredient that helps water and oil to mix together, aka emulsifier.
The number at the end refers to the oil-loving part and the bigger the number the more emulsifying power it has. 20 is a weak emulsifier, rather called solubilizer used commonly in toners while 60 and 80 are more common in serums and creams.
We don't have description for this ingredient yet.
If you are reading here, we are pretty sure the words retinoids and retinol ring a bell, but if not, you are seriously missing out, please click here immediately to catch up. The TL;DR version is that retinoids are the royal family of skincare with tretinoin being the king, the only FDA-approved ingredient to treat the signs of photoaging. Retinol is like a grandkid, it has to be converted (through two steps) in the skin to become retinoic acid. The conversion means retinol is both less effective and less harsh on the skin.
So where does our current molecule, Retinal, aka Retinaldehyde fit into the family (btw, here is a nice visual family tree about who is who)? Remember that retinol needed two conversion steps to become retinoic acid? Yes, you are right, Retinal is the intermediate step between retinoic acid and retinol, meaning it needs only one conversion step to become active in the skin. If we go with our royal family analogy, Retinal is Prince William, directly next in line to the throne.
Once retinal is converted, it becomes retinoic acid and does the same things we detailed in our tretinoin description. In a nutshell, it is everything you expect from an anti-aging superstar such as decreased wrinkles, smoother, firmer and more elastic skin.
This sounds good, but how does Retinal compare to retinoic acid? Good question! We found a study (a pretty good one with 125 patients) that compared 0.05% retinal with 0.05% retinoic acid (and vehicle). They concluded that "at week 18, a significant reduction of the wrinkle and roughness features was observed with both retinaldehyde and retinoic acid." and the difference between the two was not statistically significant. (Interestingly, in both groups, the results were less significant at week 44, so it might be a good idea to have a retinoid break from time to time?) Also, our guy, Retinal was much better tolerated than retinoic acid known for its harshness.
The good tolerability of retinal was also confirmed by another study that compared retinol (ROL), retinal (RAL) and retinoic acid (RA). They found that "the natural retinoids ROL and RAL do have a good tolerance profile, in contrast with the irritating potential of RA", meaning retinal is an awesome alternative if you have irritation and flaking issues with prescription products, such as Retin-A.
Last, but not least, we want to mention a pretty big (but subjectively evaluated), Avene (the French pharmacy brand famous for its Retinal products) sponsored study that examined the tolerability and efficacy of a 0.1 Retinal + 6% glycolic acid product in the treatment of acne. The product was added next to the standard anti-acne regimen of 1,709 patients for 90 days and the study concluded that the formula was both very well tolerated as well as effective next to other standard anti-acne medications such as benzoyl peroxide and antibiotics.
Overall, if you are into retinoids, Retinal is a really awesome and well-proven member of the family that is absolutely worth trying.
A sugar ester (sucrose + lauric acid) that works as an emulsifier and oil thickener. It's a great ingredient to make oily gel cleansers that turn to milk on contact with water.
It's also 100% natural and combined with glycerin and oils (trade name Sucragel), it gives the basis for a gentle, yet effective, moisturizing oily gel cleansers. According to the manufacturer's 20 person study, skin is twice as hydrated 2 hours after using a Sucragel based cleanser compared to using a moisturising Sodium Laureth Sulfate cleanser.
- 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
The extract coming from ginger, the lovely spice that we all know from the kitchen. It is also a medicinal plant used both in Chinese and Ayurvedic medicine for pretty much everything you can imagine (muscular pain, sore throat, nausea, fever or cramps, just to give a few examples).
As for ginger and skincare, the root extract contains the biologically active component called gingerol that has potent antioxidant and anti-inflammatory properties. Combined with Bisabolol, the duo works synergistically to sooth the skin and take down redness.
Other than that, ginger also contains moisturizing polysaccharides, amino acids, and sugars, and it is also quite well known to increase blood circulation and have a toning effect.
Last but not least, Ginger also has some volatile, essential oil compounds (1-3%). Those are mostly present in ginger oil, but small amounts might be in the extract as well (around 0.5% based on manufacturer info).
A really multi-functional helper ingredient that can do several things in a skincare product: it can bring a soft and pleasant feel to the formula, it can act as a humectant and emollient, it can be a solvent for some other ingredients (for example it can help to stabilize perfumes in watery products) and it can also help to disperse pigments more evenly in makeup products. And that is still not all: it can also boost the antimicrobial activity of preservatives.
A handy multifunctional ingredient that works as a preservative booster, as well as an antioxidant and soothing agent.
A polymeric (big molecule from repeated subunits) emulsifier that comes from Inulin, a naturally occurring polysaccharide found in the roots and rhizomes of several plants. The emulsifier is obtained by adding oil-loving chains onto inulin. The resulting copolymer can emulsify high amounts of oil and can stabilize oil droplets or non-water soluble particles so that they do not clump together in the formula.
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| what‑it‑does | solvent |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient |
| what‑it‑does | solvent | moisturizer/humectant |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | emollient | emulsifying |
| irritancy, com. | 0, 1 |
| what‑it‑does | emollient | viscosity controlling |
| irritancy, com. | 2, 2 |
| what‑it‑does | chelating |
| what‑it‑does | emollient | emulsifying |
| what‑it‑does | preservative |
| what‑it‑does | viscosity controlling |
| what‑it‑does | emulsifying |
| what‑it‑does | emollient | viscosity controlling | emulsifying | surfactant/cleansing |
| irritancy, com. | 1, 2 |
| what‑it‑does | skin-identical ingredient | emollient |
| irritancy, com. | 0, 1 |
| what‑it‑does | skin-identical ingredient | emollient |
| what‑it‑does | viscosity controlling |
| what‑it‑does | soothing |
| what‑it‑does | emollient | perfuming |
| irritancy, com. | 0, 3 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| what‑it‑does | preservative |
| what‑it‑does | chelating |
| what‑it‑does | antioxidant |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | emollient |
| what‑it‑does | buffering |
| what‑it‑does | emulsifying |
| irritancy, com. | 0, 1-2 |
| what‑it‑does | emulsifying | surfactant/cleansing |
| irritancy, com. | 0, 0 |
| what‑it‑does | emollient |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | emollient | emulsifying | surfactant/cleansing |
| what‑it‑does | antioxidant |
| irritancy, com. | 0-3, 0-3 |
| what‑it‑does | antioxidant | soothing |
| what‑it‑does | solvent |
| what‑it‑does | antioxidant | preservative |
| what‑it‑does | surfactant/cleansing | emulsifying |