Azelaic Acid

Highly versatile depigmenting active with selective targeting of hyperactive abnormal melanocytes while sparing normally pigmented cells, eliminating leukoderma risk. Dual action of reversible tyrosinase inhibition and anti-inflammatory PGE2 reduction is particularly valuable for post-inflammatory hyperpigmentation and darker skin types. US Rx at 15-20%; cosmetic brightening at 10% or less is effective and unrestricted in both EU and US. Endogenous naturally occurring compound with excellent safety profile.

Prescription drug at 15% (Finacea — rosacea) and 20% (Azelex — acne/hyperpigmentation). Cosmetic use at 10% or less permitted under FD&C Act without drug classification. Drug claims (treating rosacea, acne) at any concentration trigger FDA drug classification regardless of concentration.