Skin-darkening peptides are a class of polypeptides that promote melanin production in the skin, possessing skin-darkening, anti-inflammatory, photoprotective, and potential anti-skin cancer effects. These substances achieve a darker skin tone by activating melanin receptors (such as MC1R), stimulating melanocyte proliferation and melanin synthesis.
Common skin-darkening peptides include:
Melanotan II: A synthetic cyclic polypeptide hormone that potently activates melanin receptors, promoting skin pigmentation. Note that its use carries risks; misuse may increase the probability of developing melanoma.
Myristoyl Tetrapeptide-20: Promotes melanin production through a cascade reaction and also possesses significant anti-inflammatory, anti-UV damage, and photoaging protective effects; it is commonly used in cosmetic formulations.
Afamelanotide: A skin-lightening peptide approved for the treatment of erythropoietic protoporphyria (EPP), which effectively improves the skin's tolerance to light. Although it shows potential in pigment regulation, it is not currently a standard treatment for vitiligo.