Skin science article
First Aid Beauty KP Bump Eraser Body Scrub With 10% AHA Versus La Roche-Posay Lipikar Urea 10% Roughness Smoothing Lotion
First Aid Beauty KP Bump Eraser Body Scrub With 10% AHA Versus La Roche-Posay Lipikar Urea 10% Roughness Smoothing Lotion What's inside Key Ingredients Benefits Concerns Ingredients Side-by-side Pumice Water Glycolic Acid Sodium Cocoyl Isethionate Lactic Acid
First Aid Beauty KP Bump Eraser Body Scrub With 10% AHA Versus La Roche-Posay Lipikar Urea 10% Roughness Smoothing Lotion
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Pumice
Water
Glycolic Acid
Sodium Cocoyl Isethionate
Lactic Acid
Dimethicone
Stearic Acid
Cetearyl Alcohol
Sodium Hydroxide
Palmitic Acid
Glycerin
C12-15 Alkyl Benzoate
Sorbitol
Colloidal Oatmeal
Tocopherol
Chrysanthemum Parthenium Extract
Camellia Sinensis Leaf Extract
Glycyrrhiza Glabra Root Extract
Salix Nigra Bark Extract
Bisabolol
Hydrogenated Coconut Acid
Xanthan Gum
Steareth-20
Steareth-21
Myristic Acid
Sodium Isethionate
Phenoxyethanol
Potassium Sorbate
Sodium Benzoate
Leuconostoc/Radish Root Ferment Filtrate
EDTA
Pumice, Water, Glycolic Acid, Sodium Cocoyl Isethionate, Lactic Acid, Dimethicone, Stearic Acid, Cetearyl Alcohol, Sodium Hydroxide, Palmitic Acid, Glycerin, C12-15 Alkyl Benzoate, Sorbitol, Colloidal Oatmeal, Tocopherol, Chrysanthemum Parthenium Extract, Camellia Sinensis Leaf Extract, Glycyrrhiza Glabra Root Extract, Salix Nigra Bark Extract, Bisabolol, Hydrogenated Coconut Acid, Xanthan Gum, Steareth-20, Steareth-21, Myristic Acid, Sodium Isethionate, Phenoxyethanol, Potassium Sorbate, Sodium Benzoate, Leuconostoc/Radish Root Ferment Filtrate, EDTA
Urea
Butyrospermum Parkii Butter
Brassica Campestris Seed Oil
Dicaprylyl Carbonate
Isopropyl Palmitate
Pentylene Glycol
Glycine
Silica
Allantoin
Sorbitan Oleate
Sorbitan Tristearate
Glyceryl Stearate
PEG-100 Stearate
PEG-20 Methyl Glucose Sesquistearate
Isohexadecane
Sodium Lactate
Mannose
Hydroxyacetophenone
Hydroxyethylpiperazine Ethane Sulfonic Acid
Caprylyl Glycol
Citric Acid
Trisodium Ethylenediamine Disuccinate
Polysorbate 80
Acrylamide/Sodium Acryloyldimethyltaurate Copolymer
Acrylates/C10-30 Alkyl Acrylate Crosspolymer
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
Chlorhexidine Digluconate
Water, Urea, Glycerin, Butyrospermum Parkii Butter, Brassica Campestris Seed Oil, Dicaprylyl Carbonate, Isopropyl Palmitate, Pentylene Glycol, Glycine, Cetearyl Alcohol, Silica, Stearic Acid, Allantoin, Sorbitan Oleate, Sorbitan Tristearate, Glyceryl Stearate, PEG-100 Stearate, PEG-20 Methyl Glucose Sesquistearate, Isohexadecane, Sodium Hydroxide, Sodium Lactate, Myristic Acid, Palmitic Acid, Mannose, Hydroxyacetophenone, Hydroxyethylpiperazine Ethane Sulfonic Acid, Caprylyl Glycol, Citric Acid, Trisodium Ethylenediamine Disuccinate, Xanthan Gum, Polysorbate 80, Acrylamide/Sodium Acryloyldimethyltaurate Copolymer, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Tocopherol, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Chlorhexidine Digluconate
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.
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.
Myristic Acid, aka tetradecanoic acid, is a naturally occurring fatty acid found in coconut oil and palm oil.
In skincare, it is an:
Research indicates that this ingredient posts a low risk of irritation and sensitization.
Since myristic acid is a C14 fatty acid, it falls within the range that Malassezia can metabolize, and therefore not fungal acne safe.
Palmitic Acid is a fatty acid naturally found in our skin and in many plant and animal sources.
In cosmetics, it is usually derived from palm oil. It serves many purposes in skincare, acting as a cleanser, emollient, and emulsifier.
Interestingly, topically applied Palmitic Acid can be elongated into longer chain fatty acids and ceramides. A 2019 study found low levels of Palmitic Acid lead to slower development of cells, suggesting it plays a role in keeping your skin's renewal process on track.
The CIR (Cosmetic Ingredient Review) panel determined it safe as used in cosmetics at concentrations up to 13%. It is non-irritating and non-sensitizing in clinical studies.
The culprit behind fungal acne, the Malassezia yeast, feeds on fatty acids with carbon chain lengths between C11-C24. Palmitic Acid, at C16, falls right into that sweet spot.
In vitro studies have shown that Palmitic Acid is one of the fatty acids that induce rapid Malassezia growth in lab settings.
It's worth noting that what feeds yeast in a lab doesn't necessarily feed it on your face since formulation and your skin's chemistry play a bigger role.
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.
Stearic Acid is a fatty acid that is already found in your skin. It's one of the free fatty acids that works alongside ceramides and cholesterols to maintain your barrier.
In cosmetics, it is a multitasker:
Safety-wise, the CIR Expert Panel has concluded it to be safe in cosmetics when formulated to be non-irritating and non-sensitizing.
Free stearic acid is a C18 fatty acid that the Malassezia yeast can substrate, so this ingredient may not be fungal acne safe.
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!
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.