Skin science article
The INKEY List Retinol Serum Versus REN Clean Skincare Bio Retinoid Youth Serum
The INKEY List Retinol Serum Versus REN Clean Skincare Bio Retinoid Youth Serum This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture. This anti-aging serum is formulated
The INKEY List Retinol Serum Versus REN Clean Skincare Bio Retinoid Youth Serum
This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture.
This anti-aging serum is formulated around Niacinamide to soften the look of wrinkles and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycerin
Butylene Glycol
Propanediol
Dicaprylyl Carbonate
Retinyl Acetate
Dimethicone
Phenoxyethanol
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Caprylyl Glycol
Phospholipids
Squalane
Glycine Soja Oil
Carbomer
Polysorbate 60
Tocopheryl Acetate
Glycolipids
Sodium Hydroxide
Sodium Phytate
Sorbitan Isostearate
Glycine Soja Sterols
Tetrahexyldecyl Ascorbate
Leuconostoc/Radish Root Ferment Filtrate
Hyaluronic Acid
Sodium Lactate
Tocopherol
Polysorbate 20
Palmitoyl Tetrapeptide-7
Palmitoyl Tripeptide-1
Water, Glycerin, Butylene Glycol, Propanediol, Dicaprylyl Carbonate, Retinyl Acetate, Dimethicone, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Caprylyl Glycol, Phospholipids, Squalane, Glycine Soja Oil, Carbomer, Polysorbate 60, Tocopheryl Acetate, Glycolipids, Sodium Hydroxide, Sodium Phytate, Sorbitan Isostearate, Glycine Soja Sterols, Tetrahexyldecyl Ascorbate, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Sodium Lactate, Tocopherol, Polysorbate 20, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1
Caprylic/Capric Triglyceride
Niacinamide
Cetyl Phosphate
Coco-Caprylate/Caprate
Cetyl Alcohol
Arginine
Rosa Canina Fruit Oil
Triticum Vulgare/Aestivum Grain Extract
Crambe Abyssinica Seed Oil
Benzyl Alcohol
Astrocaryum Murumuru Seed Butter
Glyceryl Stearate
Sodium Hyaluronate
Bidens Pilosa Extract
Sodium Dehydroacetate
Linum Usitatissimum Seed Oil
Sclerotium Gum
Parfum
Xanthan Gum
Dehydroacetic Acid
Rosa Damascena Extract
Gossypium Herbaceum Seed Oil
Zea Mays Oil
Xanthophylls
Helianthus Annuus Seed Oil
Rosmarinus Officinalis Leaf Extract
Lactic Acid
Citronellol
Geraniol
Linalool
Water, Caprylic/Capric Triglyceride, Glycerin, Niacinamide, Cetyl Phosphate, Coco-Caprylate/Caprate, Squalane, Cetyl Alcohol, Arginine, Rosa Canina Fruit Oil, Triticum Vulgare/Aestivum Grain Extract, Crambe Abyssinica Seed Oil, Benzyl Alcohol, Astrocaryum Murumuru Seed Butter, Glyceryl Stearate, Sodium Hyaluronate, Bidens Pilosa Extract, Sodium Dehydroacetate, Linum Usitatissimum Seed Oil, Sclerotium Gum, Parfum, Tocopherol, Xanthan Gum, Dehydroacetic Acid, Rosa Damascena Extract, Gossypium Herbaceum Seed Oil, Zea Mays Oil, Xanthophylls, Helianthus Annuus Seed Oil, Rosmarinus Officinalis Leaf Extract, Lactic Acid, Sodium Hydroxide, Citronellol, Geraniol, Linalool
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.
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.
Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).
It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.
This is due to how structurally similar it is to what your skin already produces.
Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.
Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.
No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).
Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.
This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.
The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.
Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.
A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.
The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.
Tocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
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.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
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!