How long does MT-2 (Melanotan II) take to work?
In the first week of MT-2 (Melanotan II), strong nausea early, facial flush, spontaneous erections in male users. Around week 4, visible pigmentation if UV exposure paired. Side effects fade. By week 8, maintenance dosing holds tan with weekly use. Response varies between people, this is the commonly reported pattern, not a guarantee.
Week by week
- Week 1: Strong nausea early, facial flush, spontaneous erections in male users.
- Week 4: Visible pigmentation if UV exposure paired. Side effects fade.
- Week 8: Maintenance dosing holds tan with weekly use.
References
- Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study — Dorr RT, Lines R, Levine N, Brooks C, Xiang L, Hruby VJ, Hadley ME — Life Sciences, 1996;58(20):1777-84
- Melanotropic peptides: more than just 'Barbie drugs' and 'sun-tan jabs'? — Langan EA, Nie Z, Rhodes LE — British Journal of Dermatology, 2010;163(3):451-5
Pepdex is an editorial reference, not medical advice. Peptides vary in legal and approval status by country, many are research compounds without full human safety data. Talk to a qualified clinician before starting anything.
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Last updated 2026-06-06.