Skin science article
Shani Darden Retinol Reform Versus The INKEY List Retinol Serum
Shani Darden Retinol Reform Versus The INKEY List Retinol Serum This smoothing serum is formulated around Lactic Acid and Retinol to refine skin texture and soften the look of wrinkles. This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl T
Shani Darden Retinol Reform Versus The INKEY List Retinol Serum
This smoothing serum is formulated around Lactic Acid and Retinol to refine skin texture and soften the look of wrinkles.
This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Caprylic/Capric Triglyceride
Glycerin
Pyrus Malus Fruit Extract
Lactic Acid
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Lactobacillus Ferment
Isohexadecane
Retinol
Copernicia Cerifera Cera
Glucosamine Hcl
Plankton Extract
Camellia Sinensis Leaf Extract
Aloe Barbadensis Leaf Juice
Tocopheryl Acetate
Niacinamide
Hydrogenated Lecithin
Linoleic Acid
Glycine Soja Sterols
Phospholipids
Propanediol
Sodium Cocoamphoacetate
Sorbitan Isostearate
Polysorbate 60
Oryza Sativa Bran Extract
Rosmarinus Officinalis Leaf Extract
Helianthus Annuus Extract
Tocopherol
Cyamopsis Tetragonoloba Gum
Maltodextrin
Xanthan Gum
Lecithin
Hydrolyzed Algin
Xylitylglucoside
Anhydroxylitol
Xylitol
Tetrasodium Glutamate Diacetate
BHT
BHA
Sodium Hydroxide
Phenoxyethanol
Caprylyl Glycol
Ethylhexylglycerin
Hexylene Glycol
Water, Caprylic/Capric Triglyceride, Glycerin, Pyrus Malus Fruit Extract, Lactic Acid, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Lactobacillus Ferment, Isohexadecane, Retinol, Copernicia Cerifera Cera, Glucosamine Hcl, Plankton Extract, Camellia Sinensis Leaf Extract, Aloe Barbadensis Leaf Juice, Tocopheryl Acetate, Niacinamide, Hydrogenated Lecithin, Linoleic Acid, Glycine Soja Sterols, Phospholipids, Propanediol, Sodium Cocoamphoacetate, Sorbitan Isostearate, Polysorbate 60, Oryza Sativa Bran Extract, Rosmarinus Officinalis Leaf Extract, Helianthus Annuus Extract, Tocopherol, Cyamopsis Tetragonoloba Gum, Maltodextrin, Xanthan Gum, Lecithin, Hydrolyzed Algin, Xylitylglucoside, Anhydroxylitol, Xylitol, Tetrasodium Glutamate Diacetate, BHT, BHA, Sodium Hydroxide, Phenoxyethanol, Caprylyl Glycol, Ethylhexylglycerin, Hexylene Glycol
Butylene Glycol
Dicaprylyl Carbonate
Retinyl Acetate
Dimethicone
Squalane
Glycine Soja Oil
Carbomer
Glycolipids
Sodium Phytate
Tetrahexyldecyl Ascorbate
Leuconostoc/Radish Root Ferment Filtrate
Hyaluronic Acid
Sodium Lactate
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
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
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.
Glycine Soja Sterols are plant-derived fatty alcohols (phytosterols) from soybean.
You can think of them like the plant world's version of cholesterol; they're structurally similar enough to slot into your skin's lipid barrier and help it do its job.
Phytosterols aid skin barrier recovery by traveling deeper into the skin rather than just sitting on top of it. Once inside, they reduce transepidermal water loss (TEWL) and keep skin feeling soft / supple.
Research on phytosterols in keratinocyte and macrophase models has shown meaningful inhibition of pro-inflammatory mediators. This supports their reputation as a calming ingredient for reactive or sensitive skin.
Subjects with soy allergies did not show a reaction to phytosterols in safety tests, but it wouldn't hurt to patch test if you do have a soy allergy.
Fungal acne: Malassezia uses sterols to build its own cell walls so there's a theoretical concern that it could also make use of sterol ingredients in skincare.
Though no study has actually proven this happens with topical products, we err on the side of caution and list this ingredient as not safe for fungal acne. However, it may not be a trigger for everyone.
This is a synthetic polymer. It helps improve the texture of products by adding thickness and gel-like feel.
It is also an emulsifer, meaning it prevents ingredients such as oil and water from separating. It also helps evenly disperse other ingredients.
Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.
On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.
Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.
Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.
Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.
Phospholipids are a family of skin-identical lipids that makeup the structural backbone of every cell membrane in your body.
In cosmetics, they function as skin conditioning agents with emulsifier and surfactant properties. They're typically sourced from soybean or sunflower lecithin (or sometimes egg yolk or marine sources).
Because they mirror the lipids naturally found in the deeper layers of your skin, topical phospholipids help reinforce the lipid matrix, reduce transepidermal water loss, and leave skin feeling conditioned.
They're also used to form liposomes, or tiny self-assembling vesible used to stabilize actives like vitamin c or retinol. This helps these ingredients integrate into the upper layers of skin more easily.
Phospholipids are compatible with everything and the CIR Expert Panel has concluded them to be safe at current use levels.
Some types of phospholipids include:
Polysorbate 60 is used to help stabilize products. It is a surfactant and emulsifier. These properties help keep ingredients together in a product. Surfactants help reduce surface tension between ingredients with different states, such as liquids and solids. Emulsifiers help prevent oils and waters from separating.
Polysorbate 60 is sorbitol-based and created from the ethoxylation of sorbitan. Ethoxylation is a chemical reaction used to add ethylene oxide. Sorbitan is a the dehydrated version of sorbitol, a sugar found in fruits.
In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.
Polysorbates are commonly used in medicine and foods.
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
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.
Sorbitan Isostearate is an emulsifer. It is created from isostearic acid and sorbitol.
As an emulsifier, it keeps the water and oil ingredients from separating. This keeps formulas stable and smooth.
In a 24 hour occlusive patch test on 56 subjects, 10% sorbitan isostearate was completely non-irritating. Most formulas use less than 10%.
Because it's a fatty acid ester, it may not be fungal acne safe since the Malassezia yeast can utilize it as a nutrient source.
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.
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.
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!