2-mercaptonicotinyl glycine

2-mercaptonicotinyl glycine (2-MNG), commercially known as Melasyl, is a proprietary small molecule developed by L'Oréal for the treatment of skin hyperpigmentation. It represents a novel class of depigmenting agents that function as melanin precursor trappers. Unlike traditional tyrosinase inhibitors that block the initial enzymatic step of melanogenesis, 2-MNG binds to reactive intermediates such as dopaquinone, preventing their polymerization into melanin. This mechanism allows for the reduction of localized hyperpigmentation, such as acne-induced post-inflammatory hyperpigmentation (AI-PIH), without disrupting the basal melanin production necessary for natural skin color. Clinical data presented at the AAD 2026 meeting demonstrated that a serum containing 2-MNG significantly improves pigmentary spot density and skin tone, particularly in individuals with darker skin phototypes (IV-VI). It is the primary active ingredient in the La Roche-Posay Mela B3 product line.

Brand names

Melasyl

Other names

2-mercaptonicotinoyl glycine2-mercaptonicotinylglycine