Melanotan II dosage and evidence

What is Melanotan II?

How does Melanotan II work?

It switches on many melanocortin receptors at once. MC1R makes the skin darken. MC4R, in the brain, affects appetite and sex drive.

What have studies in people found about Melanotan II?

Melanotan II has almost no controlled human data for what people buy it for. Its whole published human record is three small University of Arizona studies from 1996 to 2000, in about 23 men. Every one of them measured erections, not tanning. What has piled up since is a safety record made of single case reports.

• Both Arizona erection studies pooled, 20 men: 17 of 20 got an erection with no sexual stimulation, lasting about 41 minutes at useful firmness on average. More sexual desire was reported after 13 of 19 drug doses, against 4 of 21 dummy doses. Severe nausea hit 12.9% of men at 0.025 mg/kg.
• Erection problems with a physical cause: 10 men got 0.025 mg/kg under the skin and a dummy shot, twice each, and wore a firmness monitor for 6 hours. They reported erections after 12 of 19 drug shots, against 1 of 21 dummy shots. Firm erections lasted 45.3 minutes on average, against 1.9 minutes. Severe nausea followed 4 of the 19 drug shots.
• Erection problems with a psychological cause (already cited): 10 men, 8 of whom had clear erections. Nausea, stretching and yawning were more common than on the dummy shot.
• An early safety study (already cited): 3 men injected it for two weeks. Their skin darkened. Most doses caused mild nausea, and the 0.03 mg/kg dose caused sleepiness and tiredness. Spontaneous erections lasted 1 to 5 hours.
• No trial in any country has tested melanotan II for tanning, in any number of people, at any dose.
• The safety record is case reports. A 2017 review of unregulated use counted four published cases of melanoma, the deadliest skin cancer, arising in existing moles during or soon after melanotan use. It also noted a growing number of reports of moles changing and new odd-looking moles. Several national health bodies have issued warnings.
• Single reports include a 20-year-old fair-skinned woman diagnosed with melanoma three months after a 3 to 4 week course of self-injection alongside sunbed use. Another describes loss of blood supply to part of a kidney, in a review that also notes earlier cases of muscle breakdown and kidney failure. There are also reports of painful erections that would not go down after an overdose.

What this does not tell you: Twenty-three supervised men dosed for days to two weeks is not a safety record. For tanning, the use that drives the market, there is no record at all. Nothing describes years of on-and-off self-injection, which is how people really use it. Nothing describes women, or anyone using it only to tan. The case reports cannot show that melanotan II causes melanoma. The people described were often using sunbeds too, and nobody counts the users who came to no harm. The reports do not rule it out either. The proposed way it could cause harm is by stimulating the pigment cells that become melanoma. On top of that, what is sold as melanotan II is unlicensed and untested. So a report of harm may not even be about this molecule.

What do people who took Melanotan II report?

This is what real people say happened to them, good and bad. Nobody measured it. A report cannot tell a real effect from the lift people get just from expecting it to work, from a diet or training change made at the same time, or from what was really in the vial. We still put it near the top. It is the next best thing to a study in people: what happens when real people use it, including what goes wrong.

• The described pattern is a low starting amount, often a quarter of a milligram or less daily, worked upward toward half a milligram or a little more, then dropped to a weekly amount once people are satisfied with the colour. The long half life is given repeatedly as the reason accumulation over days matters more than any single injection.
• Nausea dominates the complaints. It is commonly described as arriving within fifteen to twenty minutes of an injection, as worse above roughly half a milligram, and as fading after the first week or two of continued use. Injecting before sleep is the workaround most often described.
• Pigment change is described as requiring ultraviolet exposure to appear at all, and the resulting colour is repeatedly described as recognisably different from a natural tan. Paler skin types describe yellow or red tones rather than brown.
• New freckles and darkening of existing moles come up constantly and are the reason several people give for stopping. Darkening of cuts and scrapes, and long lasting marks from minor injuries, are described as well.
• Sexual effects are reported by people who were not seeking them, including spontaneous and prolonged erections lasting many hours, alongside flushing, yawning and stretching. A specific safety warning circulates against combining it with erectile dysfunction medication on the same day because of priapism risk. Lower sex drive and lower appetite are also described, pointing the other way.
• Reports of little or no colour change despite escalating amounts exist, and others in the same threads attribute them to batch quality rather than to the compound. Counterfeit and mislabelled product is a running theme in cosmetic peptide discussion, which makes every no-effect report ambiguous.

Sources: Melanotan experience and question threads on Bluelight, ExcelMale and VialTalk, found by site-restricted search and read directly, September 2026. Nothing above is attributed to any specific post and no post is reproduced.

The state of the research

The evidence, in charts

The studies we cite

• Study in people1996
  Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study

  The first look at this compound in people was tiny, and the side effect it turned up became the reason people buy it. Three male volunteers took shots under the skin for two weeks. Their skin darkened, which was the point. Most doses made them feel sick, and the highest left them drowsy and tired. They also got spontaneous erections lasting one to five hours. Three people cannot tell you how common any of that is, or whether the compound is safe.

  Three male volunteers dosed subcutaneously for two weeks: increased pigmentation, mild nausea at most doses, somnolence and fatigue at 0.03 mg/kg, and spontaneous penile erections lasting 1 to 5 hours after dosing.

  PMID 8637402 Life Sciences
• Study in people1998
  Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study

  It produced erections in most of the men who tried it, and made most of them feel sick. 10 men whose erection problems had no physical cause took Melanotan-II and a dummy in turn, so each man was his own comparison. Neither the men nor their doctors knew which shot was which. Eight of the ten got erections they noticed clearly. Nausea, stretching and yawning were far more common on the drug. Ten men is far too few to say anything about safety.

  10 men with psychogenic erectile dysfunction: Melanotan-II produced clinically apparent erections in 8 of 10, with nausea, stretching and yawning more frequent than placebo.

  PMID 9679884 Journal of Urology
• Study in people2009
  Alpha-melanocyte-stimulating hormone-induced eruptive nevi

  This is a single case report, and the warning inside it is worth more than its size suggests. A man who had already had melanoma grew crops of new abnormal moles while injecting a synthetic version of the hormone this peptide copies. His doctors warn that these peptides can push pigment cells to multiply, which is the wrong direction for someone whose pigment cells have turned cancerous before. One case cannot tell you how often this happens. It can tell you the risk is not theoretical.

  Case report of a man with prior melanoma who developed crops of new atypical nevi while self-injecting synthetic alpha-MSH; the authors warn that such peptides can drive proliferation of neoplastic melanocytes in predisposed people.

  PMID 19380666 Archives of Dermatology
• Study in people2000
  Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction

  Melanotan II produced erections in men with erectile dysfunction, and made several of them badly sick. Ten men took both the drug and a dummy injection on separate occasions, and nobody involved knew which was which on the day. They reported an erection after most of the drug injections and after one of the dummy ones. A firmness monitor backed that up. Severe nausea followed about one in five of the drug injections. Ten men is the whole study.

  10 men with organic erectile dysfunction, 0.025 mg/kg subcutaneously in a double-blind crossover: reported erections after 12 of 19 drug injections against 1 of 21 placebo doses, mean tip rigidity above 80% for 45.3 minutes against 1.9 minutes (p = 0.047), and severe nausea after 4 of 19 injections.

  PMID 11018622 Urology
• Study in people2000
  Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II

  This pools every man the Arizona group ever dosed, and it comes to twenty. Across two studies, seventeen of the twenty had an erection with no sexual stimulation at all, lasting about forty minutes at useful firmness. They also reported wanting sex more often on the drug than on the dummy injection. Severe nausea hit about one in eight at the dose used. Twenty men with erectile dysfunction is the entire human record of this peptide working.

  The pooled Arizona experience in 20 men with psychogenic and organic erectile dysfunction: erection without sexual stimulation in 17 of 20, a mean of 41 minutes of tip rigidity above 80%, increased desire after 13 of 19 doses against 4 of 21 on placebo, and severe nausea in 12.9% of subjects at 0.025 mg/kg.

  PMID 11035391 International Journal of Impotence Research
• Study in people2014
  Melanoma associated with the use of melanotan-II

  One woman, one tumour, and no way to know what caused it. A twenty year old with fair skin injected melanotan II for three or four weeks to deepen a sunbed tan. Three months later she was diagnosed with a melanoma on her buttock. She was using ultraviolet light at the same time, which is a known cause on its own. A single case can never establish blame. It can put a question on the record, and this one does.

  A 20 year old woman with Fitzpatrick type II skin was diagnosed with cutaneous melanoma of the gluteal region three months after a 3 to 4 week course of melanotan II self-injection intended to augment sunbed tanning. A single case, with concurrent ultraviolet exposure.

  PMID 24355990 Dermatology
• Study in people2020
  Melanotan II: a possible cause of renal infarction: review of the literature and case report

  A man lost the blood supply to part of a kidney and his doctors blamed melanotan II. The report describes the event and reviews earlier reports of muscle breakdown and kidney failure in people using the same peptide. The authors suggest a clot or direct damage to tissue as the route. This is one case, written up by the doctors who saw it. It cannot show how often this happens, or whether it happens at all beyond these few reports.

  A case of renal infarction attributed to melanotan II, with a review noting previously described rhabdomyolysis and renal failure and proposing thrombotic and direct toxic mechanisms. Case-level evidence only.

  PMID 31953620 CEN Case Reports
• Study in people2019
  Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials

  The owned descendant of this chemistry was tested properly, and it worked a little. Two large trials gave bremelanotide or a dummy injection to 1,267 women before menopause who had lost interest in sex. Desire rose and distress fell on the drug, by a real but small margin. Nausea, flushing and headache were all commoner on the drug. This is what melanotan II's own effects look like once somebody funds the trial, and it is not melanotan II.

  Context for where the melanocortin money went: 1,267 premenopausal women randomized across two Phase 3 trials of bremelanotide, the owned descendant of this chemistry, with significant but small gains in desire and reductions in distress, and more nausea, flushing and headache than placebo.

  PMID 31599840 Obstetrics and Gynecology
• Review of studies2017
  Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review

  The safety record for melanotan is made of individual stories, not studies. This review counted four published reports of melanoma appearing in an existing mole during or soon after melanotan use, plus a growing set of reports of moles changing and new odd ones appearing. The authors say plainly that nothing here proves the peptide causes melanoma. Several national health bodies have issued warnings anyway. Nobody is counting the users who came to no harm, so the size of the risk is unknown.

  Counts four published case reports of melanoma emerging from existing moles during or shortly after melanotan use, alongside reports of melanocytic change and new dysplastic naevi, and notes that conclusive evidence linking the two is lacking and that multiple national health organisations have issued warnings.

  PMID 28266027 International Journal of Dermatology