Evidence Grade C — Moderate human evidence. 194 published studies, 46 human. 1 registered clinical trial.
Medically reviewed by a licensed medical professional
Melanotan II is a synthetic peptide that activates multiple body systems simultaneously — producing tanning, sexual arousal, appetite suppression, and other effects. Developed at the University of Arizona, it was never approved because its non-selective action made it impossible to develop for a single condition. Bremelanotide (Vyleesi), an approved treatment for low sexual desire, was derived from Melanotan II by isolating just one of its effects.
Melanotan II is also known by these brand and alternate names:
194 published studies: 46 human, 134 animal, 14 in-vitro, 8 reviews
Melanotan II has no marketing authorisation from any regulatory agency. Early clinical studies confirmed simultaneous tanning and erectile effects, but its non-selective receptor profile and multiple simultaneous actions prevented pharmaceutical development as a single-indication drug.
Melanotan II is widely available through unregulated channels. Reported adverse effects in case reports and surveillance data include nausea, facial flushing, changes to moles (including darkening of existing nevi), and cardiovascular effects. The non-selective receptor activation profile means users are exposed to multiple pharmacological effects simultaneously, some of which (particularly changes to pigmented lesions) have raised safety concerns. Products from unregulated sources lack pharmaceutical quality assurance.
Research indicates Melanotan II is a non-selective melanocortin agonist, activating MC1R (tanning), MC3R (energy balance), MC4R (sexual arousal and appetite suppression), and MC5R. This non-selectivity produces multiple simultaneous effects — a characteristic that made it unsuitable for targeted pharmaceutical development. The selective MC4R agonist bremelanotide (#40) was developed to isolate the sexual function effects.
Research suggests all human studies involved extremely small numbers (3-20 participants), no Phase III trials were ever conducted, and no comprehensive safety database exists. The compound was explicitly abandoned for pharmaceutical development due to safety concerns and non-selectivity. Reported adverse effects from case reports and surveillance include nausea, facial flushing, changes to moles (including darkening of existing moles — raising melanoma screening concerns), and cardiovascular effects. Products from unregulated sources carry additional risks of contamination and purity variation. This compound carries significant safety concerns from a harm reduction perspective.
PeptideTrace tracks 1 registered clinical trial for Melanotan II sourced from ClinicalTrials.gov.
Melanotan II (MT-II) as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental Vitiligo
Melanotan II is a cyclic heptapeptide truncated alpha-MSH analogue developed at the University of Arizona. Sequence: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. Contains the core His-D-Phe-Arg-Trp pharmacophore with a lactam bridge between Lys and Asp. Molecular weight: 1,024.2 Da. CAS: 121062-08-6. Molecular formula: C50H69N15O9. Half-life approximately 33 minutes. Research suggests it is approximately 1,000x more potent than endogenous alpha-MSH. It has never been approved by any regulatory agency and is widely available as an unregulated grey-market research chemical. Health agencies worldwide (FDA, MHRA, TGA, NoMA) have issued warnings against its use. The Swedish Poisons Information Centre recorded 215 adverse event cases from 2008-2019.
Research suggests Melanotan II is a non-selective melanocortin receptor agonist affecting four receptor subtypes. MC1R activation drives tanning via melanogenesis (eumelanin production without UV requirement). MC3R activation research suggests modulates energy homeostasis. MC4R activation in the hypothalamus drives sexual arousal via central nervous system pathways fundamentally different from PDE5 inhibitors, and suppresses appetite via satiety circuits. MC5R activation regulates exocrine gland secretions. The non-selectivity across all melanocortin receptors is the fundamental source of both its multiple reported effects and its safety concerns.
Tanning (Dorr et al., 1996; N=3): Two of 3 subjects showed increased pigmentation after only 5 low doses (0.025 mg/kg) every other day. Sexual function (Wessells et al., 1998; N=10 psychogenic ED): 8 of 10 men developed erections; mean tip rigidity >80% duration was 38.0 vs 3.0 minutes (P=0.0045). In organic ED (N=10), 9 of 10 reported erections on at least one injection, with increased sexual desire in 68% vs 19% (P<0.01). Safety concerns are significant: multiple case reports of eruptive melanocytic nevi and severe dysplasia (Schulze et al., 2014: >100 nevi after single injection, 3 with severe dysplasia); melanoma cases reported though causal relationship unproven; cardiovascular sympathomimetic toxidrome (tachycardia up to 146 bpm, hypertension 151/85); rhabdomyolysis with CPK of 17,773 IU/L from overdose; renal infarction reported. Development was abandoned in 2000 in favor of bremelanotide.
The information on this page is provided for educational and research reference purposes only. This is not medical advice. Always consult a qualified healthcare professional before making any health-related decisions.
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This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making decisions about your health.
