Melanotan II

Melanotan II is a synthetic analogue of the peptide hormone α-melanocyte-stimulating hormone (α-MSH) that stimulates melanogenesis, the production of melanin in the skin. It activates melanocortin receptors MC1R (tanning), MC3R and MC4R (libido and appetite effects). The peptide is known for its ability to produce a tan with reduced UV exposure, potentially offering photoprotection. Beyond tanning, Melanotan II has notable effects on sexual function and appetite regulation, making it distinct from Melanotan I. The peptide works systemically after subcutaneous injection, with effects typically developing over several weeks of use.

Melanotan II is administered subcutaneously, typically 2 times per week for a 4-week tanning cycle. The educational dose is 0.25–0.5 mg per injection during the loading phase. Some protocols start with lower doses (0.25 mg) to assess tolerance before increasing to 0.5 mg. The peptide activates MC1R for melanin synthesis (tanning) and MC3/4R for libido effects. A typical 4-week cycle with 2 injections per week totals 8 injections. Melanotan II is often stacked with PT-141 for enhanced libido benefits, though they should be administered with separate syringes at different injection sites.