2.5
A potent chemical that breaks down hair proteins, but carries a high risk of skin and eye irritation — best left to professional use.
Irritation
high
Source
synthetic
beautyhaircaredepilatory
Read ingredient reviewBeauty ingredient research
Beauty ingredients explained in plain English
Browse the review database to understand what an ingredient is, what it does in a beauty formula, when it is useful, and when it deserves caution across skincare, haircare, bodycare, makeup, and more.
20769
Reviewed ingredients
524
Low-concern standouts
2884
Need usage caution
Showing 14 of 14
AllUV absorberUV filterabrasiveabsorbentacne treatmentactiveactive ingredientadhesivealkalizing agentamino acidanti-aginganti-androgenanti-cavityanti-cavity agentanti-inflammatoryanti-irritantanticariesanticavity agentantidandruffantifungalantimicrobialantioxidantantiperspirantantiplaqueastringentbarrier repairbarrier supportbarrier-repairbarrier-supportbinderbinding agentbiotechbiotechnologybond-builderbotanicalbotanical extractbotanical oilbotanical waterbrighteningbrightening agentbufferbuffering agentcell-communicating ingredientceramidechelating agentchemicalchemical intermediateclaycleansercleansingcleansing agentcolorantconditionerconditioningconditioning agentcooling agentcosmeticcosmetic additivecosmetic colorantcosmetic ingredientcosmetic pigmentcosmetic powdercosmetic-texturizercosmetic-waxcosmeticscrosslinking agentdelivery agentdelivery systemdenaturantdeodorantdeodorant agentdepigmenting agentdepilatorydepilatory agentdesensitizing agentdyedye intermediatedye precursordye-intermediateemollientemulsifierenzymeessential oilexfoliantexperimentaleyelashfermentfilm formerfilm-formerfilm-formingfilm-forming agentfirming agentfixativeflavoring agentformulationfragrancefragrance ingredientfunctional ingredientgashair carehair colorhair coloranthair conditionerhair dyehair removalhair-carehair-colorhaircarehumectantindustrialinsecticideintermediatelashlash carelash enhancerlash-and-browlip carelipidmakeupmarine extractmasking agentmicrobiomemicrobiome modulatormineralmoisturizernail carenail-careocclusiveoilopacifieropacifying agentoptical agentoral careotheroxidative dyeoxidative dye precursoroxidizing agentpH adjusterpain reliefpenetration enhancerpeptidepersonal careph adjusterpharmaceuticalpheromonepigmentplant oilplasticizerpolymerpolymer precursorprebioticprescription-drugpreservativepreservative boosterprobioticprocessing agentprocessing aidpropellantproteinpurifyingreducing agentretinoidscalp caresebum regulatorsebum-regulatorself-tannerself-tanningsensory additivesensory agentsensory modifiersiliconeskin barrierskin barrier supportskin conditionerskin conditioningskin conditioning agentskin lighteningskin protectantskin-conditioningskin-conditioning agentskin-identicalskin-identical ingredientskin-lighteningskin-lightening agentskincaresolventsoothingsoothing agentstabilizerstimulantsunscreensurfactantsyntheticsynthetic colorantsynthetic dyesynthetic resinsynthetic-coloranttexture enhancertexturizerthickenertoneruv-absorberuv-filtervasoactivevasodilatorviscosity controlviscosity controllingviscosity controlling agentvitaminwax
2.5
Calcium sulfide is an effective hair remover but can be harsh and irritating, especially for sensitive skin.
Irritation
high
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.5
Calcium Thioglycolate is a proven hair-removal ingredient, but it can irritate sensitive skin and has a strong odor.
Irritation
moderate
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.5
A potent depilatory chemical that dissolves hair but can irritate sensitive skin if left on too long.
Irritation
moderate
Source
synthetic
beautyhair removaldepilatory
Read ingredient review3.5
Ethyl Cysteinate HCl is an effective hair-softening ingredient in depilatory and straightening products, but it can be irritating and should be used with caution.
Irritation
moderate
Source
synthetic
beautyhair caredepilatory
Read ingredient review2.5
Ethyl Thioglycolate is an effective hair-removal chemical but can be irritating and has a strong odor, so it requires careful formulation and use.
Irritation
high
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.5
An effective hair-removal chemical, but can be irritating and has a strong odor.
Irritation
moderate
Source
synthetic
beautyskincaredepilatory
Read ingredient review2.5
Mercaptopropionic acid is a potent chemical used in professional hair treatments and depilatories, but it carries a high risk of skin and eye irritation and is not recommended for regular at-home use.
Irritation
high
Source
synthetic
beautyhaircaredepilatory
Read ingredient review2.0
Methyl thioglycolate is a potent chemical that breaks down hair protein, but it can cause skin irritation and burns if misused.
Irritation
high
Source
synthetic
beautyhaircaredepilatory
Read ingredient review3.5
Phenylthioglycolic acid is a synthetic depilatory ingredient that breaks down hair keratin, but it can be irritating and is not intended for leave-on skincare.
Irritation
moderate
Source
synthetic
beautyskincaredepilatory
Read ingredient review2.0
Potassium sulfide is an effective depilatory but can be highly irritating to skin and eyes; use with caution and follow product instructions exactly.
Irritation
high
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.0
Effective for hair removal but can be irritating and has a strong odor; use with caution and follow instructions closely.
Irritation
high
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.5
Strontium thioglycolate is a common active in depilatory creams that dissolves hair, but it can be irritating and has a strong odor.
Irritation
moderate
Source
synthetic
beautyskincaredepilatory
Read ingredient review3.5
Thiodiglycolic acid is a strong reducing agent used in professional hair treatments to alter curl or remove hair, but it can be irritating and is not for daily skincare.
Irritation
moderate
Source
synthetic
beautyhair caredepilatory
Read ingredient review