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pepmg Research Desk · Peer-reviewed evidence review

What the research says about Melanotan II

A neutral summary of the peer-reviewed literature on Melanotan II, a melanocortin-receptor agonist used illicitly for tanning. There are no controlled human efficacy trials, and the human record is dominated by adverse-event case reports. Research use only.

Preclinical only Melanotan II Published Jul 13, 2026 · 5 sources

Preclinical only — Animal or in-vitro studies only — no controlled human trials. This describes the state of the published literature, not a claim that this compound works, is safe, or is for human use. Research use only.

The short version

  • Melanotan II is a non-selective melanocortin-receptor agonist marketed illicitly to darken skin; it has no controlled human efficacy trials in the peer-reviewed literature [3][4].
  • The human literature is dominated by adverse-event case reports, including priapism, rhabdomyolysis and renal injury, and reports of melanocytic (mole) changes and melanoma cases [1][2][3].
  • Health authorities and reviews have issued safety warnings about the unregulated use of these substances [3].
  • This page reports what the studies and reports describe. It is not medical advice, an efficacy or safety claim, or dosing guidance. Research use only.

What Melanotan II is

Melanotan II is described in the literature as a synthetic, non-selective analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts on melanocortin receptors; its reported effects in humans include increased skin pigmentation and, through melanocortin activity, spontaneous erection and sexual stimulation [1]. It is used illicitly, injected subcutaneously, primarily to stimulate a tan [3][4]. It is sold by third-party research-chemical vendors and is offered for laboratory and research use only.

Reviews emphasize that Melanotan II is unregulated and untested for these uses, and that it should not be confused with afamelanotide, a different, thoroughly tested melanocortin analogue approved for a limited medical indication [3].

What the human and preclinical research has measured

Preclinical only

There are no controlled human efficacy trials of Melanotan II in the peer-reviewed record. What exists on humans is largely observational and safety-focused: a review of the underground market documented how melanotan is purchased illicitly online and injected, and surveyed users' motivations, noting how little is known about these unregulated substances [4].

The mechanistic and efficacy evidence is preclinical. An animal study in zebrafish reported that Melanotan II reversed memory impairment and anxiety-like changes induced by a short-term high-fat diet, which the authors described as a first look at the compound's effects on diet-induced neurobehavioral changes [5]. Findings like these are early animal experiments, not evidence of human benefit.

What the trials report on safety and adverse events

Preclinical only

Because controlled trials are absent, the human safety literature on Melanotan II is essentially a series of adverse-event case reports and safety reviews. Published cases and reviews describe acute priapism requiring medical management after injection [2], and Melanotan II has been associated with rhabdomyolysis and renal injury, including a reported case of renal infarction [1]. A dermatology review reported that unregulated melanotan use is associated with cutaneous complications, particularly changes in existing moles and new atypical moles, and noted case reports describing melanomas arising from existing moles during or shortly after melanotan use, while stating that a conclusive causal link is lacking [3].

That review also reported that multiple national health organizations have issued safety warnings about the use of these substances, and stressed the uncertainties around their preparation, dosing, and administration [3]. Because there are no controlled human trials, adverse-event rates cannot be quantified from this literature, only described. Nothing here should be read as evidence that Melanotan II is safe. This is not medical advice; consult a qualified professional and read the reports directly.

How strong is the evidence

Because there are no controlled human efficacy trials of Melanotan II and its mechanistic evidence is animal and in-vitro, the efficacy evidence base is characterized as preclinical only, while the human literature that does exist is dominated by adverse-event case reports and safety warnings [3][4][5]. This is a compound where the published human record is mostly about harm, not benefit.

Nothing here is dosing, medical, or safety guidance. Read the reports and studies themselves and consult a qualified professional. This page is a map to the evidence, not a recommendation.

Sources · 5

  1. Melanotan II: a possible cause of renal infarction: review of the literature and case report. Review · human · CEN case reports · 2020 · PMID 31953620 · DOI 10.1007/s13730-020-00447-z
  2. Melanotan-induced priapism: a hard-earned tan. Review · human · BMJ case reports · 2019 · PMID 30796078 · DOI 10.1136/bcr-2018-227644
  3. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Review · human · International journal of dermatology · 2017 · PMID 28266027 · DOI 10.1111/ijd.13585
  4. A glimpse into the underground market of melanotan. Observational · human · Dermatology online journal · 2018 · PMID 30142729
  5. Melanotan-II reverses memory impairment induced by a short-term high-fat diet. Study · animal · Biomedicine & pharmacotherapy · 2023 · PMID 37478579 · DOI 10.1016/j.biopha.2023.115129

pepmg summarizes the peer-reviewed literature and links to every source — it sells nothing, ships nothing, and gives no medical, dosing, or human-use guidance. Don't just trust this summary: follow any citation to its source and read it yourself. Research use only.