Oxothiazolidine
An amino-acid derivative. The maker links it to support for skin defense against stress; independent data are limited. Well tolerated.
Evidence by route
Topical application
An active ingredient. Well tolerated; independent data limited.
- CIR Cosmetic Ingredient Review safety assessment
How to read tiers A–F
- BLimited evidence. One RCT or several controlled studies with limitations
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Oily, Sensitive
About this ingredient
Oxothiazolidine is an amino-acid derivative (procysteine) used in cosmetics as a supporting ingredient in soothing formulas. Its INCI is Oxothiazolidine. In a product it acts as a precursor linked to glutathione synthesis, the skin's own antioxidant molecule, which is why manufacturers tie it to protection against oxidative stress. On efficacy it pays to be honest: most data come from suppliers themselves and independent evidence is thin. The sensible view is to treat it as a supporting component within a formula, not an active with solid clinical results. It promises no wonders and does not replace better-studied antioxidants such as vitamin C. Applied topically its systemic absorption is minimal, so it can be used during pregnancy and breastfeeding with no expected risk. Tolerance is good. Both irritation and allergy potential are low, so it fits sensitive skin. There is no evidence of meaningful comedogenicity.
Frequently asked questions
Is Oxothiazolidine safe during pregnancy?
Oxothiazolidine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Oxothiazolidine for?
Oxothiazolidine suits: normal, dry, combination, oily, sensitive.
What is Oxothiazolidine and what does it do in cosmetics?
An amino-acid derivative.
What's the INCI name for Oxothiazolidine?
The INCI name is Oxothiazolidine.
See Oxothiazolidine in a product composition right on the store page
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