Nonapeptide-1 ek synthetic oligopeptide hai jo alpha-melanocyte-stimulating hormone (α-MSH) antagonist ke taur par kaam karta hai. Yeh melanin ki production ko block karta hai kyunki MC1 receptor ko melanocytes par rokta hai. Isko skincare mein dark spots aur uneven skin tone ko reduce karne ke liye use kiya jata hai.