Pro Strength Retinoid Peptide Serum
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Peter Thomas Roth Pro Strength Retinoid Peptide SerumIngredients explained
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).
An emollient ester with a rich and creamy but non-greasy skin feel. It makes skin supple and protects dry skin.
A little helper ingredient that can boost the performance and enhance the delivery of active ingredients in a formula. It can penetrate deep layers of the skin helping actives to do the same.
It's especially useful to help active ingredients for self-tanning (DHA), anti-acne or skin-whitening to penetrate deeper and work better.
A clear, colorless, very easily spreadable and very volatile (evaporates from the skin easily) silicone fluid. It leaves a non-greasy, dry-smooth feel on the skin.
A super commonly used 5 unit long, cyclic structured silicone that is water-thin and does not stay on the skin but evaporates from it (called volatile silicone). Similar to other silicones, it gives skin and hair a silky, smooth feel.
It's often combined with the non-volatile (i.e. stays on the skin) dimethicone as the two together form a water-resistant, breathable protective barrier on the skin without a negative tacky feel.
A type of silicone elastomer (rubber-like material with both viscosity and elasticity) whose major function is forming a nice film on the skin.
It is also cosmetically very elegant with a non-tacky, non-oily and smooth skin feel. It also works as a stable delivery system of active materials, has sebum absorption and control properties and upon application, it transforms into a matte appearance with a powdery after feel.
A light emollient ester (C8-10 fatty acids connected to C12-18 fatty alcohols) that absorbs quickly and leaves a dry but silky finish on the skin. In terms of skin feel, it is similar to Dicaprylyl Carbonate, another commonly used light 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 and easy to formulate with. No wonder it’s popular.
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 peptide that's claimed to do three important things: stimulate collagen production, stimulate the proliferation of fibroblast cells (important, collagen making skin cells) and inhibit collagen-eating, skin damaging MMPs (matrix metalloproteinases - a group of enzymes that do bad things in the skin).
The net effect of all this is reduced appearance of lines and wrinkles and more hydrated, youthful looking skin. The manufacturer even claims that in a twelve-week in-vivo study Palmitoyl Hexapeptide-14 was compared to FDA-approved anti-aging treatment Renova (0.05% tretinoin) and the two are equivalent in reducing the appearance of fine lines and wrinkles and Palmitoyl Hexapeptide-14 does so without irritation.
That's a very promising result indeed though unfortunately, we could not find the details about the study (like how long, how many people etc.) and one study is never enough anyways, so we will just say that Palmitoyl Hexapeptide-14 is a promising anti-aging peptide (while tretinoin is a proven ani-aging superstar).
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.
We don't have description for this ingredient yet.
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.
We don't have description for this ingredient yet.
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).
We don't have description for this ingredient yet.
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).
PCA stands for Pyrrolidone Carboxylic Acid and though it might not sound like it, it is a thing that can be found naturally in our skin. The sodium salt form of PCA is an important skin-identical ingredient and great natural moisturizer that helps the skin to hold onto water and stay nicely hydrated.
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 >>
- 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
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.
The famous omega-6 fatty acid, the mother of all ω-6 fatty acids in our body. It is a so-called polyunsaturated fatty acid meaning it has more than one (in this case two) double bonds and a somewhat kinky structure that makes LA and LA-rich oils a thin liquid.
It is also an essential fatty acid meaning our body cannot synthesize it and has to take it from food. This is not hard at all as plenty of nuts (such as flax, poppy or sesame seeds) and vegetable oils (such as sunflower or safflower) are rich in LA. The hard thing seems to be eating enough omega-3-s, more specifically eating a healthy ratio of omega-6 to omega-3, but that is a topic for a what-is-good-to-eat-site and not for us.
As for linoleic acid and the skin, LA is a really important little guy found naturally in our skin. It is the most abundant fatty acid in the epidermis and it serves as a structural precursor for important skin lipids called ceramides. Knowing this, it will not come as a surprise that Linoleic acid has a central role in the structure and function of stratum corneum permeability, aka healthy skin barrier. LA deficiency leads to an impaired more permeable skin barrier and the topical application of LA-rich sunflower oil can fix this issue rapidly (while oleic-rich olive oil did not have the same barrier repairing effect).
LA is not only important for dry, barrier damaged skin types but also for acne-prone skin. Research shows that problem skin has lower levels of linoleic acid (and higher levels of oleic acid) than normal skin. So LA-deficiency in the skin seems to be connected not only to an impaired skin barrier but also to acne and smearing LA all over your face might help with your problem skin. A double-blind study using a 2.5% LA gel for 4 weeks found a 25% reduction in the size of microcomedones, the tiny blocked pores that can later lead to acne.
If that was not enough, we have one more thing to report about LA. It lightens hyperpigmentation (aka UVB caused sun spots) both by blocking the melanin production of melanocytes (the skin cells that make the pigment melanin) and by enhancing the desquamation of melanin pigment from the upper layers of the skin.
Overall, linoleic acid is a multi-functional skin goodie with barrier repairing, acne-reducing, and skin-lightening magic abilities. It's a nice one to spot on the ingredient list pretty much for any skin type.
A common fatty acid that can be found in lots of plant oils. Its name, "oleic", means derived from olive oil, a plant oil rich in oleic acid, but avocado, macadamia and marula oils, just to name a few, are also oleic rich.
Its chemical structure is monounsaturated, meaning it has one double bond (cis-9) that makes it less kinky than polyunsaturated fatty acids with multiple double bonds. Less kinkiness means that oleic acid and OA-rich oils are a bit thicker and heavier than their LA-rich siblings.
Maybe this thickness is the reason that Oleic acid is considered comedogenic, and if you have acne-prone skin avoid OA-rich plant oils, and choose linoleic acid-rich versions instead.
The thickness of OA also means that OA-rich oils are considered more nourishing and moisturizing than their LA-rich counterparts, and are generally considered to be more suitable for dry, mature skin types.
As for oleic acid in its free form (and by free we mean that it is not bound up in a triglyceride structure like it is in oils), it mostly serves as an emulsifier or emulsion stabilizer in small amounts in regular cosmetic products. It is also quite well researched and is used in the pharmaceutical industry as a penetration enhancer.
A fatty acid that can be found naturally in the skin. In fact, it's the most common saturated fatty acid found in animals and plants.
As for skincare, it can make the skin feel nice and smooth in moisturizers (emollient) or it can act as a foam building cleansing agent in cleansers. It's also a very popular ingredient in shaving foams.
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 oil mixes (aka emulsions).
We don't have description for this ingredient yet.
A high stability high oleic acid oil derived from microalgae in an eco-friendly process. It works as an emollient in the formula, similar to other vegetable oils.
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.
A heavy-duty emollient ester that comes in the form of a pale yellow semi-solid paste. It mainly stays on the surface of the skin and gives skin protection and occlusivity.
A nice odorless liquid used mainly as a superior solubilizer and efficacy booster for cosmetic active ingredients such as skincare bigshot vitamin C, self-tanning active DHA or the anti-acne gold standard, benzoyl peroxide.
Other than that it can also be used in hair care products where it gives a longer-lasting and more uniform coloring. According to a manufacturer, it might even prevent the formation of split ends.
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.
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 super versatile and common mineral powder that comes in different particle sizes. It is a multi-tasker used to improve skin feel, increase product slip, give the product light-reflecting properties, enhance skin adhesion or serve as an anti-caking agent.
It is also the most commonly used "base" material for layered composite pigments such as pearl-effect pigments. In this case, mica is coated with one or more metal oxides (most commonly titanium dioxide) to achieve pearl effect via the physical phenomenon known as interference.
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 | emollient |
| what‑it‑does | solvent | viscosity controlling |
| what‑it‑does | emollient | solvent |
| what‑it‑does | emollient |
| what‑it‑does | emollient |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | cell-communicating ingredient |
| what‑it‑does | skin-identical ingredient |
| what‑it‑does | emollient |
| what‑it‑does | soothing | emollient |
| what‑it‑does | antioxidant | soothing |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | skin-identical ingredient | moisturizer/humectant |
| irritancy, com. | 0, 0 |
| what‑it‑does | skin-identical ingredient | emollient |
| irritancy, com. | 0, 1 |
| what‑it‑does | antioxidant |
| irritancy, com. | 0-3, 0-3 |
| what‑it‑does | emollient | emulsifying |
| what‑it‑does | skin-identical ingredient | emollient | surfactant/cleansing |
| what‑it‑does | emollient | emulsifying |
| what‑it‑does | skin-identical ingredient | emollient | emulsifying |
| irritancy, com. | 0, 2 |
| what‑it‑does | emollient | viscosity controlling |
| irritancy, com. | 0, 2-3 |
| what‑it‑does | surfactant/cleansing | emulsifying | surfactant/cleansing |
| what‑it‑does | emollient |
| what‑it‑does | soothing |
| what‑it‑does | emollient |
| what‑it‑does | solvent | moisturizer/humectant | perfuming |
| irritancy, com. | 0, 0 |
| what‑it‑does | preservative |
| what‑it‑does | solvent |
| what‑it‑does | colorant |
| what‑it‑does | preservative |