In the US, azelaic acid is not listed as an OTC drug active, so cosmetic products at any concentration are permissible provided claims remain cosmetic (no 'treats acne' language). In the EU, leave-on products above 10% require a full CPSR safety assessment. AJ Cosmo Labs can connect you with cosmetic chemists who understand these jurisdictional lines and can help you build a compliant claim set from day one.
Read the full guide on Azelaic acid formulations →