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Ingredient · INCI reference

Aminoethanesulfinic Acid

A naturally occurring sulfur-containing amino acid derivative, known as hypotaurine, used in cosmetics as a skin-conditioning and antioxidant ingredient.

What it is

Aminoethanesulfinic Acid, commonly known as hypotaurine, is a small sulfur-containing molecule and the metabolic precursor to taurine. In cosmetics it is used as a conditioning ingredient and is valued for its antioxidant character, helping support the skin's defenses against oxidative stress. It is water-soluble and typically used at modest concentrations in serums and emulsions.

Safety & warnings

As a small, water-soluble amino acid derivative, it is generally well tolerated and not associated with comedogenicity or fragrance allergy. Sensitive individuals can patch test as a routine precaution.

Origin & sourcing

Can occur naturally in the body as a precursor to taurine; the cosmetic-grade material is typically produced synthetically to a defined purity.

Questions everyone asks

What is hypotaurine?

It is a sulfur-containing amino acid derivative and the precursor to taurine, used in skincare for conditioning and antioxidant support.

Why is it added to sunscreen?

It is included for its antioxidant and skin-conditioning properties, which can complement a sunscreen's protective role.

Sources & references

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