# Melanotan II - Canonical: https://residue.info/c/melanotan-ii/ - Also called: MT-II, MT-2, Melanotan 2 - Evidence grade: C (Limited / early human data). Two double-blind, placebo-controlled crossover studies of 10 men each and a 3-man phase I pilot; the abstracts do not report randomization. Later literature is mainly case reports. - Status: Not FDA-approved · FDA compounding nomination withdrawn - PubChem CID: 92432 - Updated: 2026-10-19 · Reviewed by: Residue Editorial Team Melanotan II is a lactam-bridged cyclic heptapeptide analog of α-melanocyte-stimulating hormone [1]. In a 1996 phase I pilot in three men it increased skin pigmentation and caused spontaneous erections [1]; two later 10-man crossover studies found it initiated erections in men with erectile dysfunction [2][3]. It is not FDA-approved, and FDA records published case reports of melanoma, priapism and sympathomimetic toxicity [4]. ## Key findings - In 10 men with psychogenic erectile dysfunction, 8 developed clinically apparent erections; mean time at more than 80% tip rigidity was 38.0 minutes with MT-II versus 3.0 with placebo [2]. (anchor: https://residue.info/c/melanotan-ii/#kf-pmid-9679884) - In 10 men with organic risk factors, MT-II initiated erections after 12 of 19 injections versus 1 of 21 placebo doses, and 4 of 19 injections caused severe nausea [3]. (anchor: https://residue.info/c/melanotan-ii/#kf-pmid-11018622) - In a 3-man pilot, five low subcutaneous doses increased pigmentation of the face, upper body and buttock, measured by reflectance [1]. (anchor: https://residue.info/c/melanotan-ii/#kf-pmid-8637402) - Case reports describe melanoma after self-injection with sunbed use [5], rhabdomyolysis and systemic toxicity [6], renal infarction [7] and ischemic priapism [8]. (anchor: https://residue.info/c/melanotan-ii/#kf-pmid-24355990) - FDA lists Melanotan II among withdrawn compounding nominations and cites published reports of melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism [4]. (anchor: https://residue.info/c/melanotan-ii/#kf-fda-cat2) ## Effects by system - Erectile function (grade C): Erections in 8 of 10 men with psychogenic ED and after 12 of 19 injections in men with organic risk factors, in placebo-controlled crossover studies [2][3]. (anchor: https://residue.info/c/melanotan-ii/#effect-erectile-function) - Skin pigmentation (grade C): Increased facial and body pigmentation in a 3-man phase I pilot [1]. (anchor: https://residue.info/c/melanotan-ii/#effect-skin-pigmentation) - Sexual desire (grade C): Self-reported desire higher after MT-II than placebo in one 10-man study [3]. (anchor: https://residue.info/c/melanotan-ii/#effect-sexual-desire) - Adverse effects (grade C): Nausea, yawning/stretching and reduced appetite in trials [2]; melanoma, rhabdomyolysis, renal infarction and priapism in case reports [5][6][7][8]. (anchor: https://residue.info/c/melanotan-ii/#effect-adverse-effects) ## What is Melanotan II? Melanotan II (MT-II) is Ac-Nle4-Asp5-His6-D-Phe7-Arg8-Trp9-Lys10 α-MSH(4-10)-NH2, a lactam-bridged cyclic heptapeptide with superpotent melanotropic activity in vitro [1]. PubChem lists the formula C50H69N15O9 [9]. It was developed as a tanning agent, and its effect on erections was noticed in the first human study [1]. ## How is Melanotan II thought to work? MT-II is a non-selective melanocortin-receptor agonist whose effects in humans include increased skin pigmentation, spontaneous erections and sexual stimulation [7]. Its pigmenting effect runs through the melanocortin 1 receptor [10]. Bremelanotide, approved for a desire disorder in women, has high affinity for the melanocortin type 4 receptor [11], and its PubChem record lists the same seven-residue sequence as MT-II [12][9]. ## What have studies found? **Tanning.** The 1996 phase I pilot gave three men subcutaneous MT-II or saline on alternating weekdays for two weeks. Two showed increased pigmentation one week after dosing ended [1]. **Erections.** In ten men with psychogenic erectile dysfunction, eight developed erections under RigiScan monitoring; tip rigidity above 80% lasted a mean of 38.0 minutes versus 3.0 on placebo (p=0.0045) [2]. A second ten-man study in men with organic risk factors found erections after 12 of 19 MT-II injections versus 1 of 21 placebo doses, with higher reported sexual desire [3]. **Unsupervised use.** A qualitative study of 623 UK and Irish forum posts found MT-II used mainly for tanning before holidays and competitions, often alongside sunbeds [10]. ClinicalTrials.gov lists one registered study, of MT-II added to phototherapy for vitiligo [13]. ## What are the reported harms? Case reports include a melanoma in a 20-year-old woman after a course of self-injections with sunbed use [5]; rhabdomyolysis, tachycardia and kidney injury after a 6 mg injection bought online [6]; a renal infarction [7]; and ischemic priapism requiring surgery [8]. A 2017 review counted four case reports of melanoma arising from existing moles during or shortly after melanotan use, and notes that conclusive evidence of a link is lacking [14]. Case reports cannot establish how often these harms occur. FDA lists Melanotan II among substances whose compounding nominations were withdrawn, noting immunogenicity risk and citing published case reports of melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism [4]. Drugs@FDA returned no application for it. ## What is still unknown? - **Randomized trials** of adequate size for any use; the controlled data are 23 men across three studies [1][2][3]. - **Long-term skin safety**, including any melanoma risk, which case reports raise but cannot measure [5]. ## Frequently asked questions **Is Melanotan II FDA-approved?** No. FDA lists Melanotan II among bulk substances whose compounding nominations were withdrawn and records published case reports of serious adverse events [4]. Its relative afamelanotide is approved, as Scenesse, for a single rare disease [15]. **What is the difference between Melanotan 1 and Melanotan 2?** Melanotan I is afamelanotide, a linear 13-residue α-MSH analog approved as an implant for erythropoietic protoporphyria [16][15]. Melanotan II is a shorter cyclic analog that also caused erections in trials and was never approved [1][2]. **What doses of Melanotan II were used in studies?** The 1996 pilot recommended 0.025 mg/kg/day for future phase I studies [1], and both erection studies used 0.025 mg/kg by subcutaneous injection [2][3]. These are research doses, not recommendations. **What are the side effects of Melanotan II?** In trials: nausea, stretching and yawning, decreased appetite, and in one subject grade II somnolence and fatigue [1][2]. Case reports describe melanoma, rhabdomyolysis, renal infarction and priapism [5][6][7][8]. ## Sources [1] Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Dorr RT et al. Life Sci. 1996. https://pubmed.ncbi.nlm.nih.gov/8637402/ [2] Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. Wessells H et al. J Urol. 1998. https://pubmed.ncbi.nlm.nih.gov/9679884/ [3] Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Wessells H et al. Urology. 2000. https://pubmed.ncbi.nlm.nih.gov/11018622/ [4] Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. U.S. FDA, content current as of 04/22/2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks [5] Melanoma associated with the use of melanotan-II. Hjuler KF & Lorentzen HF Dermatology. 2014. https://pubmed.ncbi.nlm.nih.gov/24355990/ [6] Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Nelson ME et al. Clin Toxicol (Phila). 2012. https://pubmed.ncbi.nlm.nih.gov/23121206/ [7] Melanotan II: a possible cause of renal infarction: review of the literature and case report. Peters B et al. CEN Case Rep. 2020. https://pubmed.ncbi.nlm.nih.gov/31953620/ [8] Melanotan Tanning Injection: A Rare Cause of Priapism. Mallory CW et al. Sex Med. 2021. https://pubmed.ncbi.nlm.nih.gov/33460908/ [9] PubChem compound record: melanotan-II. C50H69N15O9 · MW 1024.2 g/mol. https://pubchem.ncbi.nlm.nih.gov/compound/92432 [10] Melanotan II User Experience: A Qualitative Study of Online Discussion Forums. Gilhooley E et al. Dermatology. 2021. https://pubmed.ncbi.nlm.nih.gov/34464955/ [11] Bremelanotide: First Approval. Dhillon S & Keam SJ Drugs. 2019. https://pubmed.ncbi.nlm.nih.gov/31429064/ [12] PubChem compound record: Bremelanotide. C50H68N14O10 · MW 1025.2 g/mol. https://pubchem.ncbi.nlm.nih.gov/compound/9941379 [13] ClinicalTrials.gov registry search: "melanotan II" OR melanotan-II. 1 registered studies at fetch. https://clinicaltrials.gov/search?intr=%22melanotan%20II%22%20OR%20melanotan-II [14] Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Habbema L et al. Int J Dermatol. 2017. https://pubmed.ncbi.nlm.nih.gov/28266027/ [15] Drugs@FDA: SCENESSE (NDA210797). CLIVUNEL INC; original approval 2019-10-08; Prescription. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=210797 [16] PubChem compound record: Afamelanotide. C78H111N21O19 · MW 1646.8 g/mol. https://pubchem.ncbi.nlm.nih.gov/compound/16197727 --- From Residue. Research and education only; not medical advice. Quote with attribution and a link to the canonical page.