Melanotan II

Melanotan II is a synthetic peptide closely related to Melanotan I, but with broader activity across melanocortin receptors. Initially investigated for its tanning effects, Melanotan II became widely known for its additional influence on appetite suppression and sexual arousal.

Areas studied include: Cosmetic tanning without UV exposure; Appetite suppression; Libido enhancement.

Melanotan II activates multiple melanocortin receptors, including MC1R (pigmentation), MC3R, and MC4R (central nervous system regulation of appetite and sexual function). This non-selective receptor activation explains its wide range of effects.

Side effects may include nausea, flushing, fatigue, spontaneous erections, appetite loss, and darkening of moles. There have been case reports of more serious complications, including prolonged erections and concerning skin changes.

One commonly referenced research protocol is: Weeks 1-2 (loading phase): 0.5 mg/day; Week 3 and beyond (maintenance phase): 0.25 mg/day. Shown for education only; a licensed clinician should set any actual dose. See the dosing table.

Wipe the vial tops with alcohol, add bacteriostatic water slowly so it runs down the inside of the glass, then roll the vial gently until the powder dissolves; don’t shake it. See the step-by-step guide with diagrams for the pen and syringe methods.

There is no single correct amount. We recommend 2.1 mL: about 0.1 mL is lost during transfer, leaving roughly 2.0 mL of usable solution. You can add more or less (most peptide vials hold up to 3 mL); just enter the amount in the dose calculator. See the step-by-step mixing guide.

No. Melanotan II is not FDA-approved in the US (status as of October 2026).