Skin science article
Kiehl's Micro-Dose Anti-Aging Retinol Serum with Ceramides and Peptide Versus Avène RetrinAL 0.1 Intensive Cream
Kiehl's Micro-Dose Anti-Aging Retinol Serum with Ceramides and Peptide Versus Avène RetrinAL 0.1 Intensive Cream This anti-aging serum is formulated around Niacinamide and Ceramide NP to soften the look of wrinkles and refine skin texture. This anti-aging trea
Kiehl's Micro-Dose Anti-Aging Retinol Serum with Ceramides and Peptide Versus Avène RetrinAL 0.1 Intensive Cream
This anti-aging serum is formulated around Niacinamide and Ceramide NP to soften the look of wrinkles and refine skin texture.
This anti-aging treatment is formulated around Retinal 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
Pentylene Glycol
Niacinamide
Cetyl Alcohol
Isohexadecane
Isononyl Isononanoate
Diisopropyl Sebacate
2-Oleamido-1,3-Octadecanediol
4-T-Butylcyclohexanol
Acetyl Dipeptide-1 Cetyl Ester
Adenosine
Ceramide NP
Hydroxypalmitoyl Sphinganine
Lauroyl Lysine
Octyldodecanol
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
Sodium Chloride
Sodium Hyaluronate
Sodium Hydroxide
Trisodium Ethylenediamine Disuccinate
Retinol
Tocopherol
Dicaprylyl Ether
Ammonium Polyacryloyldimethyl Taurate
Behenyl Alcohol
Caprylyl Glycol
Carbomer
Cetearyl Alcohol
Cetearyl Glucoside
Glycine Soja Oil
Helianthus Annuus Seed Oil
Hydroxyethylcellulose
Lecithin
Phenethyl Alcohol
Poloxamer 188
Polycaprolactone
Sorbitan Laurate
Steareth-100
CI 40800
Chlorphenesin
Phenoxyethanol
Water, Glycerin, Butylene Glycol, Pentylene Glycol, Niacinamide, Cetyl Alcohol, Isohexadecane, Isononyl Isononanoate, Diisopropyl Sebacate, 2-Oleamido-1,3-Octadecanediol, 4-T-Butylcyclohexanol, Acetyl Dipeptide-1 Cetyl Ester, Adenosine, Ceramide NP, Hydroxypalmitoyl Sphinganine, Lauroyl Lysine, Octyldodecanol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Sodium Chloride, Sodium Hyaluronate, Sodium Hydroxide, Trisodium Ethylenediamine Disuccinate, Retinol, Tocopherol, Dicaprylyl Ether, Ammonium Polyacryloyldimethyl Taurate, Behenyl Alcohol, Caprylyl Glycol, Carbomer, Cetearyl Alcohol, Cetearyl Glucoside, Glycine Soja Oil, Helianthus Annuus Seed Oil, Hydroxyethylcellulose, Lecithin, Phenethyl Alcohol, Poloxamer 188, Polycaprolactone, Sorbitan Laurate, Steareth-100, CI 40800, Chlorphenesin, Phenoxyethanol
Triethylhexanoin
Cyclopentasiloxane
Cyclohexasiloxane
Ceteareth-20
Polymethyl Methacrylate
Ceteareth-33
Caprylic/Capric Triglyceride
Ammonium Acryloyldimethyltaurate/Vp Copolymer
Oenothera Biennis Oil
Benzoic Acid
Disodium EDTA
Retinal
Tocopheryl Glucoside
Oleoyl Dipeptide-15
Mica
Silica
BHT
Oleoyl Tetrapeptide-31
Titanium Dioxide
Caramel
CI 17200
Water, Triethylhexanoin, Cyclopentasiloxane, Cetearyl Alcohol, Cyclohexasiloxane, Ceteareth-20, Polymethyl Methacrylate, Ceteareth-33, Caprylic/Capric Triglyceride, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Oenothera Biennis Oil, Phenoxyethanol, Benzoic Acid, Disodium EDTA, Retinal, Tocopheryl Glucoside, Oleoyl Dipeptide-15, Mica, Sodium Hydroxide, Silica, BHT, Oleoyl Tetrapeptide-31, Tocopherol, Titanium Dioxide, Caramel, CI 17200
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.
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.
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.
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.
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!