Hypotaurine – amino acid, taurine precursor. In sunscreens works as a secondary antioxidant: stabilizes photo-unstable avobenzone, extending UVA protection duration. Safe, no standalone cosmetic effects.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
Functional sunscreen stabilizer. Works not as a cosmetic active but as a formula adjuvant – protects avobenzone from photodegradation (in vitro data). Safety confirmed.
Aminoethanesulfinic Acid (hypotaurine) is a sulfur-containing amino acid, a precursor of taurine in metabolism. Formed by cysteine oxidation in the hypotaurine-taurine decarboxylation pathway. Mechanism. On skin it acts as a second-order antioxidant – does not neutralize free radicals directly, but stabilizes other antioxidants and photo-unstable UV filters. Key use in sunscreens: extends avobenzone (butyl methoxydibenzoylmethane) photostability in combinations with octocrylene, diethylhexyl-2,6-naphthoate (Corapan TQ), and trisiloxane. Where applied. SPF 30+ sunscreens with avobenzone (0.1–1%). Brands: La Roche-Posay Anthelios XL, Bioderma Photoderm MAX, Avène Sun, Heliocare Advanced. Evidence base. In vitro and in vivo, 1% hypotaurine extends avobenzone photostability 1.5–2× after 2 MED UV irradiation (Bonda 2008). No direct skin effects (hydration, anti-aging) – purely a formulation ingredient. Safety. CIR confirmed safety. Hypoallergenic, non-irritating, non-comedogenic. Topical systemic absorption is minimal. Pregnancy and lactation – safe. Acceptable at any stage, including sunscreens for pregnant women with melasma. Functional role. No standalone skin effect. An invisible workhorse in avobenzone sunscreens.
Irritation potential
LowAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Aminoethanesulfinic Acid is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Aminoethanesulfinic Acid suits: normal, dry, combination, oily, sensitive.
Hypotaurine – amino acid, taurine precursor.
The INCI name is Aminoethanesulfinic Acid. It may also appear as: Hypotaurine, Гипотаурин, Аминоэтансульфиновая кислота.
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