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Melanotan II Benefits: Claims vs What Studies Show

Benefits people claim for Melanotan II, set against what published studies measured, and where no study exists.

Medical review pendingMelanocortin agonistUpdated
Strongest evidence
Human RCT
Human / animal studies
12 / 2
in our evidence file (PubMed search, 2 Oct 2026)
FDA status
Not approved
Off Category 2, 15 Apr 2026

Claimed benefits and what studies show

Each row is an area where people claim a benefit, with the strongest study we summarise behind it. Animal and cell results are labelled and are not human results. User reports are not counted as evidence here.

Melanotan II claimed benefits and the studies behind them
ClaimBest evidenceStudies (human / animal)What was measuredPage
TanningHuman RCT evidence, 4 of 43 / 0Skin pigmentation (tanning); Tanning with few doses; Motivation for useEvidence for tanning
Erectile dysfunctionHuman RCT evidence, 4 of 41 / 1Erection without sexual stimulation; Sexual desire; Proceptive sexual behaviourEvidence for erectile dysfunction
Weight lossAnimal evidence, 2 of 40 / 1Feeding and fat pad sizeEvidence for weight loss

Strongest study per claim: Tanning, Life sciences 1996, PMID 8637402; Erectile dysfunction, International journal of impotence research 2000, PMID 11035391; Weight loss, Journal of neuroendocrinology 2003, PMID 12535159.

What the studies measured

Melanotan II outcomes in published studies
OutcomeResultStudy typeSource
Erection without sexual stimulation17 of 20 men had penile erection without sexual stimulation.Human controlled trialn = 20International journal of impotence research 2000, PMID 11035391
Sexual desireIncreased desire after 13/19 (68%) MT-II doses vs 4/21 (19%) placebo (P<0.01).Human controlled trialn = 20International journal of impotence research 2000, PMID 11035391
Skin pigmentation (tanning)Two of the three subjects had increased pigmentation measured by reflectance and by eye.Human controlled trialn = 3Life sciences 1996, PMID 8637402
Tanning with few dosesTanning activity seen with only 5 low doses given every other day.Human controlled trialn = 3Life sciences 1996, PMID 8637402
Motivation for useUsers mainly sought a tan, often before holidays or physique competitions.Human observationaln = 205Dermatology 2021, PMID 34464955
User-reported tanning outcomeThe single case reported a darker skin tone and positive experiences.Human case reportn = 1The International journal on drug policy 2014, PMID 24280586
Proceptive sexual behaviourBoth doses increased hops/darts and ear wiggling in hormone-primed female rats; pacing and lordosis unchanged.Animal · rat (not a human result)n = 14Pharmacology, biochemistry, and behavior 2006, PMID 17113634
Feeding and fat pad sizeCentral MT-II infusion produced a transient drop in feeding and reduced fat pad size in rats.Animal · rat (not a human result)Journal of neuroendocrinology 2003, PMID 12535159
Not shown in any study we cite. Searches behind this page: PubMed search on 2 Oct 2026 for “"melanotan II"[tiab] OR "melanotan 2"[tiab]”: 198 results. PubMed search on 2 Oct 2026 for “("melanotan II"[tiab] OR melanotan[tiab]) AND humans[mh]”: 82 results. PubMed search on 2 Oct 2026 for “("melanotan II"[tiab] OR "melanotan 2"[tiab] OR melanotan[ti]) AND (case[tiab] OR naevi[tiab] OR nevi[tiab] OR melanoma[tiab] OR adverse[tiab] OR priapism[tiab] OR tanning[tiab] OR sunless[tiab]) AND humans[mh]”: 25 results. PubMed search on 2 Oct 2026 for “("melanotan II"[tiab] OR "melanotan 2"[tiab]) AND (half-life[tiab] OR pharmacokinetic*[tiab])”: 3 results.

What MT2 is claimed to do, and where the claims come from

A qualitative study of UK and Ireland online forums found that people use melanotan II mainly to pursue a tanned appearance, including ahead of fitness or body-building competitions.[3]

The same forum analysis lists dosing regimens, misinformation about an unregulated product, sunbed use and side effects among the themes it identified.[3]

A case report describes melanotan products being sold over the Internet to induce sunless tanning and used as sexual stimulants.[11]

Tanning: claimed versus studied

In the only human pilot cached, two subjects had increased pigmentation of the face, upper body and buttock 1 week after dosing ended.[2]

The pilot authors concluded tanning activity in humans after 5 low subcutaneous doses every other day; a pilot this small cannot show how often tanning occurs.[2]

A case report links a 3- to 4-week course of melanotan II self-injections, used with sunbeds, to a melanoma found 3 months later; a single case cannot show cause.[12]

Libido and erections: claimed versus studied

In 20 men with erectile dysfunction, melanotan II led to penile erection without sexual stimulation in 17 of 20 men.[1]

Increased sexual desire was reported after 13 of 19 doses of melanotan II against 4 of 21 doses of placebo.[1]

In ovariectomised female rats, intravenous melanotan II at 1 and 3 mg/kg increased solicitation behaviours; this is animal data and not evidence for women.[5]

Weight loss and appetite: claimed versus studied

In rats given melanotan II by continuous central infusion, almost full anorexia lasted 1 to 2 days and feeding then returned to normal; this is animal data.[6]

In the same rat study, melanotan II reduced adiposity by a factor of two against pair-fed rats; the route was central infusion and no human result is attached.[6]

Of the 6 abstracts cached for this page (8637402, 11035391, 24280586, 34464955, 17113634, 12535159), 0 report a weight outcome in people.

Calculated from abstracts checked 8637402, 11035391, 24280586, 34464955, 17113634, 12535159; human weight outcomes reported 0. Formula: count of checked abstracts with a human weight outcome = 0

What the same literature reports on harms

A 39-year-old man who injected 6 mg of melanotan II developed systemic toxicity with rhabdomyolysis; the dose was reported by the patient and the product purity is unknown.[11]

One case report describes acute low-flow priapism after a subcutaneous melanotan injection.[13]

More on Melanotan II

DosageSide effectsResultsHow it works

Common questions

Is Melanotan II proven to work?

The strongest study we summarise for Melanotan II is human rct evidence, among 14 studies. A trial result is not an approval; see the legal status.

What does MT2 do?

A review states that melanotan II is a non-selective melanocortin-receptor agonist whose effects in humans are increased skin pigmentation, spontaneous penile erection and sexual stimulation.[14]

Does melanotan 2 have benefits beyond tanning?

Only tanning and erection outcomes appear in the human abstracts cached here; the weight and appetite results come from rats, so 0 of the 6 checked abstracts show a human benefit beyond those two.

Calculated from abstracts checked 6; human outcomes beyond tanning and erection 0. Formula: count = 0

More on Melanotan II

DosageDoses used in published studies, with the source for each.CalculatorVial, water and dose to syringe units.Side effectsWhat labels and studies report, and what is unknown.ResultsStudy outcomes and when they were measured.PricePrice per mg and per week from dated listings. No vendor links.How it worksTarget, mechanism and how long it acts, from the label or studies.

Sources

  1. 1Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II.International journal of impotence research · 2000PMID 11035391Accessed 2 Oct 2026
  2. 2Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study.Life sciences · 1996PMID 8637402Accessed 2 Oct 2026
  3. 3Melanotan II User Experience: A Qualitative Study of Online Discussion Forums.Dermatology (Basel, Switzerland) · 2021PMID 34464955Accessed 2 Oct 2026
  4. 4An in-depth case examination of an exotic dancer's experience of melanotan.The International journal on drug policy · 2014PMID 24280586Accessed 2 Oct 2026
  5. 5The melanocortin agonist, melanotan II, enhances proceptive sexual behaviors in the female rat.Pharmacology, biochemistry, and behavior · 2006PMID 17113634Accessed 2 Oct 2026
  6. 6The melanocortin agonist Melanotan-II reduces the orexigenic and adipogenic effects of neuropeptide Y (NPY) but does not affect the NPY-driven suppressive effects on the gonadotropic and somatotropic axes in the male rat.Journal of neuroendocrinology · 2003PMID 12535159Accessed 2 Oct 2026
  7. 7PubMed search: "melanotan II"[tiab] OR "melanotan 2"[tiab] (198 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  8. 8PubMed search: ("melanotan II"[tiab] OR melanotan[tiab]) AND humans[mh] (82 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  9. 9PubMed search: ("melanotan II"[tiab] OR "melanotan 2"[tiab] OR melanotan[ti]) AND (case[tiab] OR naevi[tiab] OR nevi[tiab] OR melanoma[tiab] OR adverse[tiab] OR priapism[tiab] OR tanning[tiab] OR sunless[tiab]) AND humans[mh] (25 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  10. 10PubMed search: ("melanotan II"[tiab] OR "melanotan 2"[tiab]) AND (half-life[tiab] OR pharmacokinetic*[tiab]) (3 results)PubMed · 2026pubmed.ncbi.nlm.nih.govAccessed 2 Oct 2026
  11. 11Melanotan II injection resulting in systemic toxicity and rhabdomyolysis.Clinical toxicology (Philadelphia, Pa.) · 2012PMID 23121206Accessed 2 Oct 2026
  12. 12Melanoma associated with the use of melanotan-II.Dermatology (Basel, Switzerland) · 2014PMID 24355990Accessed 2 Oct 2026
  13. 13Melanotan-induced priapism: a hard-earned tan.BMJ case reports · 2019PMID 30796078Accessed 2 Oct 2026
  14. 14Melanotan II: a possible cause of renal infarction: review of the literature and case report.CEN case reports · 2020PMID 31953620Accessed 2 Oct 2026

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