A synthetic, non-selective melanocortin receptor agonist sold on the gray market as an injectable tanning and libido peptide. It is not approved by any regulator, and it is a different molecule from melanotan-1 (afamelanotide).
Reviewed for accuracy · Last reviewed July 8, 2026Melanotan II (MT-2) is a synthetic cyclic peptide that activates melanocortin receptors non-selectively (across MC1R, MC3R, MC4R, and MC5R rather than one receptor), which is why it affects pigmentation, appetite, sexual function, and cardiovascular tone at once. It is sold through gray-market "research" channels as an injectable tanning and libido peptide. It is not approved by any regulator for any use, and authorities in the US, UK, and elsewhere have warned against it.
It is important not to confuse Melanotan II with melanotan-1 (afamelanotide). Melanotan-1 is a different, MC1R-selective molecule that has an approved product (SCENESSE) for a rare light-sensitivity disorder. Melanotan II is more potent, non-selective, and unapproved. This page is only about Melanotan II. Because MT-2 has no approved label, every figure below traces to anecdotal reports or published case reports, not a prescribing guideline.
Melanotan II has no approved dose. Gray-market use is described as small daily subcutaneous "loading" injections until a tan appears, then occasional maintenance, but these figures are anecdotal and unvalidated.
Read the full Melanotan II dosage guide →Reported effects include nausea, flushing, reduced appetite, spontaneous erections and priapism, blood pressure changes, and darkening or eruption of moles, with case reports of dysplastic nevi and melanoma in users.
Read the full Melanotan II side effects guide →Gray-market peptide vials are typically kept refrigerated and away from light, and reconstituted product is generally refrigerated. Purity and contents are not guaranteed for an unapproved product. See the full storage & safety guide for general handling basics.
This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Melanotan II is not approved by any regulator. Talk to a doctor before considering any compound.