Skin science article
SK-II R.N.A. POWER Anti-Aging Face Cream Versus The INKEY List Peptide Moisturizer
SK-II R.N.A. POWER Anti-Aging Face Cream Versus The INKEY List Peptide Moisturizer This anti-aging moisturizer is formulated around Galactomyces Ferment Filtrate and Niacinamide to soften the look of wrinkles and strengthen the skin barrier. What's inside Key
SK-II R.N.A. POWER Anti-Aging Face Cream Versus The INKEY List Peptide Moisturizer
This anti-aging moisturizer is formulated around Galactomyces Ferment Filtrate and Niacinamide to soften the look of wrinkles and strengthen the skin barrier.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycerin
Galactomyces Ferment Filtrate
Isohexadecane
Niacinamide
Isopropyl Isostearate
Butylene Glycol
Butyrospermum Parkii Butter
Caprylic/Capric Triglyceride
Pentylene Glycol
Dimethicone
Phytosteryl/Behenyl/Octyldodecyl Lauroyl Glutamate
Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer
Stearyl Alcohol
Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Cetyl Alcohol
Behenyl Alcohol
Panthenol
Tocopheryl Acetate
Benzyl Alcohol
Dimethiconol
Cetearyl Alcohol
Cetearyl Glucoside
Methylparaben
PEG-100 Stearate
Polymethylsilsesquioxane
Polysorbate 80
Stearic Acid
Disodium EDTA
Propylparaben
Sodium PEG-7 Olive Oil Carboxylate
Ethylparaben
Sorbitan Oleate
Chlorella Vulgaris Extract
PEG-7 Glyceryl Cocoate
Sodium Hydroxide
Parfum
Acanthopanax Senticosus Root Extract
Hydrolyzed Soy Protein
Cynara Scolymus Leaf Extract
Polyquaternium-7
Hydrolyzed Yeast Protein
Palmitoyl Pentapeptide-4
Methylsilanol Tri-PEG-8 Glyceryl Cocoate
Methicone
CI 77891
CI 77492
Water, Glycerin, Galactomyces Ferment Filtrate, Isohexadecane, Niacinamide, Isopropyl Isostearate, Butylene Glycol, Butyrospermum Parkii Butter, Caprylic/Capric Triglyceride, Pentylene Glycol, Dimethicone, Phytosteryl/Behenyl/Octyldodecyl Lauroyl Glutamate, Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer, Stearyl Alcohol, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Cetyl Alcohol, Behenyl Alcohol, Panthenol, Tocopheryl Acetate, Benzyl Alcohol, Dimethiconol, Cetearyl Alcohol, Cetearyl Glucoside, Methylparaben, PEG-100 Stearate, Polymethylsilsesquioxane, Polysorbate 80, Stearic Acid, Disodium EDTA, Propylparaben, Sodium PEG-7 Olive Oil Carboxylate, Ethylparaben, Sorbitan Oleate, Chlorella Vulgaris Extract, PEG-7 Glyceryl Cocoate, Sodium Hydroxide, Parfum, Acanthopanax Senticosus Root Extract, Hydrolyzed Soy Protein, Cynara Scolymus Leaf Extract, Polyquaternium-7, Hydrolyzed Yeast Protein, Palmitoyl Pentapeptide-4, Methylsilanol Tri-PEG-8 Glyceryl Cocoate, Methicone, CI 77891, CI 77492
C12-15 Alkyl Benzoate
Glyceryl Stearate Se
Betaine
Phenoxyethanol
Carbomer
Sodium Stearoyl Glutamate
Ethylhexylglycerin
Sodium Gluconate
Dehydroacetic Acid
Hydrogenated Lecithin
Phenethyl Alcohol
Acetyl Hexapeptide-37
Maltodextrin
Pentapeptide-48
Water, Caprylic/Capric Triglyceride, Glycerin, C12-15 Alkyl Benzoate, Cetearyl Alcohol, Glyceryl Stearate Se, Betaine, Butylene Glycol, Phenoxyethanol, Benzyl Alcohol, Carbomer, Butyrospermum Parkii Butter, Sodium Stearoyl Glutamate, Sodium Hydroxide, Ethylhexylglycerin, Sodium Gluconate, Tocopheryl Acetate, Dehydroacetic Acid, Hydrogenated Lecithin, Phenethyl Alcohol, Acetyl Hexapeptide-37, Maltodextrin, Pentapeptide-48
Reviews
Be the first to review
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Benzyl Alcohol is an aromatic alcohol with several roles: it's a preservative, solvent, and mild fragrance component with a floral scent.
This ingredient has been deemed safe for use in cosmetic formulations at concentrations up to 5%, and up to 10% in hair dyes. You'll typically see 0.5-2% in most rinse-off or leave-on products.
As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.
The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.
This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.
It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.
Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.
At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
This ingredient is also known as shea butter. It is a plant-derived extract from the nuts of the Africa shea tree and one of the most well-studied emollients.
Because it has a high concentration of fatty acids (primarily oleic, stearic, and linoleic) it is able to form a protective barrier on the skin's surface. This helps seal in moisture and prevents transepidermal water loss (TEWL).
In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).
Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.
Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.
It plays several roles in a formula:
Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.
Multiple assessments have found it to be non-irritating and non-sensitizing to most people.
However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.
Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.
Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.
Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.
This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.
A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.
Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.
Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.
This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.
Just know very high concentrations (>40%) can feel tacky in low humidity.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Sodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.
In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.
"Alkaline" refers to a high pH level. A low pH level would be considered acidic.
Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.
Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.
The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.
Most leave-on skincare keeps it at the lower end, often between 0.5-1%.
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!