Regulatory Status
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Safety Data
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Expert Verdict
Aminothiol depigmenting agent with strong clinical evidence for melasma treatment at 5%. EU: permitted without specific concentration limit; USA: permitted in cosmetics but no OTC monograph; Japan: prohibited in cosmetics except rinse-off hair setting agents. Safe under short-contact rinse-off protocol; leave-on use carries unquantified systemic exposure and elevated sensitization risk (13.5% patch test positivity rate).
Regulatory Flags
Frequently Asked Questions
Is Cysteamine safe in cosmetics?
Aminothiol depigmenting agent with strong clinical evidence for melasma treatment at 5%. EU: permitted without specific concentration limit; USA: permitted in cosmetics but no OTC monograph; Japan: prohibited in cosmetics except rinse-off hair setting agents. Safe under short-contact rinse-off protocol; leave-on use carries unquantified systemic exposure and elevated sensitization risk (13.5% patch test positivity rate). The EU classifies Cysteamine as "permitted". Safety rating: MODERATE.
Is Cysteamine allowed in the EU?
Cysteamine EU regulatory status: permitted. Maximum allowed concentration: 5%. This is based on EU Regulation 1223/2009 and its amendments.
What does Cysteamine do in cosmetics?
Cysteamine functions as: Multi-mechanism depigmenting aminothiol; shifts melanogenesis from eumelanin (dark) toward pheomelanin (lighter) via glutathione/thiol pathway; also inhibits tyrosinase, scavenges dopaquinone intermediate, and chelates iron and copper ions involved in melanin biosynthesis. It is classified as a Active Ingredient in our database. CAS number: 156-57-0.
What is the Margin of Safety for Cysteamine?
not established The Margin of Safety (MoS) is calculated using SCCS methodology. A MoS above 100 is generally considered safe. Use the MoS Calculator tool to calculate MoS for your specific formulation and product category.
Compliance Tools
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Related Ingredients
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