Peptide■America

Melanocortins

Melanotan II

Melanotan-2; MT-II

US status
No lawful route
Class
Melanocortins
Approved product
None
Route
None lawful; sold as research-use-only material

By Diane Walker · Reference Editor · Reviewed August 2026

Regulatory record

4 dated actions on record; FDA final action still open (hollow marker).
April 2020
FDA warns a Kentucky compounding pharmacy that drug products it compounded using Melanotan II and twenty-one other substances are not eligible for the exemptions in section 503A(a), because the substances are not the subject of an applicable USP or NF monograph, are not a component of an FDA-approved human drug, and do not appear on the 503A bulks list.
April 2026
The nomination is withdrawn by its nominators and Melanotan II leaves Category 2 of the interim 503A bulks list. It is not added to Category 1, and it appears in no category of the list FDA published on May 14, 2026.
August 2026
FDA still publishes its Category 2 safety finding for the substance among those nominated but withdrawn: compounded drugs containing Melanotan II may pose a risk for immunogenicity, and published case reports discuss melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome, and priapism. The withdrawal removed the substance from the category; it did not retract the finding.
FDA final action
None as of August 2026.

Every entry above is dated; the record is current as of the review date.

Definition

Melanotan II is a synthetic cyclic analogue of alpha-melanocyte-stimulating hormone. It is a non-selective agonist at melanocortin receptors, which is the source of both the pigmentation it is sold for and the effects it was actually studied for.

The compound is marketed almost entirely as a tanning agent. Its human record is not a tanning record; it is a sexual-function record, and the distance between the two is the central fact of this page.

Evidence

Four records carry a clinical-trial publication type across five name variants, and all four were read individually rather than counted. A 1996 pilot phase I study established that the peptide produced measurable melanogenesis and, incidentally, spontaneous erections in the men who received it [1]. The three that followed pursued the incidental finding: a double-blind placebo-controlled crossover study in men with psychogenic erectile dysfunction [2], a summary of the human melanocortin work [3], and a study in men with organic erectile dysfunction [4].

The census is the finding. Across the variants "melanotan II", "melanotan-II", "melanotan 2", "melanotan-2", and "MT-II peptide", PubMed returns 360 indexed records, of which 119 carry the Humans subject heading, 4 the clinical-trial publication type, and 1 the randomized-controlled-trial type [5]. Every one of the four was published between 1996 and 2000. Not one studies tanning, which is the use the compound is sold for; the human record for that use is empty, and it has been empty for twenty-six years.

What has accumulated instead is a case-report literature. Melanoma has been reported in association with use [6], as have renal infarction [7], priapism [8], and systemic toxicity with rhabdomyolysis after injection [9]. Case reports establish association rather than cause, and the honest statement is that the published harms are documented while the published benefit for the marketed use does not exist.

Lawful access

There is no lawful United States supply route. Melanotan II was placed in Category 2 of FDA's interim section 503A bulks list — the category for substances that raise significant safety risks — and left that category in April 2026 when its nominators withdrew the nomination. It was not added to Category 1. On the list FDA published on May 14, 2026 it appears in no category at all [10].

Removal did not retract the finding. FDA continues to publish the safety statement for Melanotan II among substances nominated but withdrawn: compounded drugs containing it may pose a risk for immunogenicity, and published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome, and priapism [11]. A substance whose safety statement still stands and whose nomination no longer does is further from lawful compounding than it was before, not closer. The research-only page sets out why removal from a list is not permission.

FDA has also addressed the compound in enforcement. In April 2020 it warned a compounding pharmacy that drug products compounded using Melanotan II and twenty-one other substances were not eligible for the exemptions in section 503A(a), because the substances were not the subject of an applicable USP or NF monograph, were not a component of an FDA-approved human drug, and did not appear on the 503A bulks list [12]. Material sold under this name today is research-use-only chemical supply, produced and sold outside pharmacy licensure and prescriber oversight.

Elsewhere in this index

Filed under

Evidence reviews

Reference tables

Same class

References

  1. Dorr RT, Lines R, Levine N, et al. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996;58(20):1777–1784. PMID 8637402
  2. Wessells H, Fuciarelli K, Hansen J, et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. J Urol. 1998;160(2):389–393. PMID 9679884
  3. Wessells H, Levine N, Hadley ME, et al. Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II. Int J Impot Res. 2000;12 Suppl 4:S74–S79. PMID 11035391
  4. Wessells H, Gralnek D, Dorr R, et al. Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Urology. 2000;56(4):641–646. PMID 11018622
  5. PubMed, National Library of Medicine. Census run 2026-08-31 across five name variants — "melanotan II" OR "melanotan-II" OR "melanotan 2" OR "melanotan-2" OR "MT-II peptide" — returning 360 indexed records, 119 carrying the Humans MeSH term, 4 under "clinical trial"[Publication Type] and 1 under "randomized controlled trial"[Publication Type]. All four trial-type records were opened and read; every one concerns erectile function or sexual desire and every one was published between 1996 and 2000. The publication-type filter was proved live in the same run against a control term returning 8,904 records under the clinical-trial type and 6,113 under the randomized type; the invalid tag clinicaltrial[pt] returned 0 for that control term in the same run, and a deliberately invalid record identifier errored in the same run. Source
  6. Paurobally D, Jason F, Dezfoulian B, et al. Melanotan-associated melanoma. Br J Dermatol. 2011;164(6):1403–1405. PMID 21564053
  7. Peters B, Hadimeri H, Wahlberg R, et al. Melanotan II: a possible cause of renal infarction: review of the literature and case report. CEN Case Rep. 2020;9(2):159–161. PMID 31953620
  8. Dreyer BA, Amer T, Fraser M. Melanotan-induced priapism: a hard-earned tan. BMJ Case Rep. 2019;12(2). PMID 30796078
  9. Nelson ME, Bryant SM, Aks SE. Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Clin Toxicol (Phila). 2012;50(10):1169–1173. PMID 23121206
  10. US Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act, updated May 14, 2026. Read in full 2026-08-31: Melanotan II appears in none of Category 1, Category 2, or Category 3. Source
  11. US Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, content current as of April 22, 2026, table of bulk drug substances nominated but withdrawn. Read 2026-08-31. Source
  12. US Food and Drug Administration. Warning letter, Tailor Made Compounding LLC, case 594743, April 1, 2020. Read 2026-08-31. Source
  13. PubMed, National Library of Medicine. Census extended 2026-09-01 on the same five name variants as reference 5. The union re-measured at 360 indexed records, 119 tagged Humans, 4 under "clinical trial"[Publication Type] and 1 under "randomized controlled trial"[Publication Type], identical to the 2026-08-31 run. Combined with "case reports"[Publication Type] the names return 23 records, 21 of them tagged Humans; combined with the term melanoma they return 17 records, 9 of them case reports; combined with the terms tanning, tan or sunless they return 23 records, of which exactly 1 carries a trial publication type, and that record is the 1996 pilot phase I study in three volunteers. The publication-type filter was proved live in the same run against a control term returning 8,906 records under the clinical-trial type and 6,115 under the randomized type; the invalid tag clinicaltrial[pt] returned 0 for that control term, and a deliberately invalid record identifier errored at the start and the end of the run. Source
  14. US Food and Drug Administration, Drugs@FDA through the openFDA drugsfda endpoint. Queried 2026-09-01 on the generic name, the substance name and the brand name for "melanotan": no matching application. Control in the same run: the identical query for "bremelanotide" returned NDA 210557. Source