MT-II, MT-2
Evidence Grade C — Moderate human evidence. 194 published studies, 46 human. 1 registered clinical trial.
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.
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.
Melanotan II (MT-II) as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental Vitiligo
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Histrelin is available as Supprelin LA for central precocious puberty (approved 2007). The Vantas implant for prostate cancer was approved in 2004 but discontinued in 2021. The implant requires a minor surgical procedure for insertion and removal/replacement each year. Supprelin LA's main clinical advantage is its 12-month duration — the longest of any GnRH agonist — which is particularly valuable in paediatric patients where treatment compliance over years is important. Clinical studies demonstrated effective suppression of puberty markers in over 97% of patients. The implant has also seen significant off-label use in gender-affirming care as a puberty blocker, where its annual dosing schedule offers practical benefits for adolescent patients and their families.
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