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Melanotan II: what the studies show, status and safety

Status at a glance

MarketStatusDate
United StatesNot approved—
European UnionNot approved—
GermanyNot approved—
United KingdomNot approved—
AustraliaScheduled substance—
CanadaNot approved—
SwitzerlandNot approved—
Development stage
Discontinued
Strongest evidence
Phase 1 randomised trial
WADA status
Prohibited (S0, 2026)
Last verified
2026-09-06
Version
1.0

Melanotan II: what the studies show, status and safety

Summary

Melanotan II is a lab-made peptide designed in the 1980s at the University of Arizona, and no country has ever approved it. Its clinical development stopped after four small studies in fewer than 25 men, all published between 1996 and 2000 by a single research group. The FDA points to published case reports of melanoma, brain swelling, a stimulant-like poisoning and painful prolonged erection. Two laboratories that measured products sold online found far less peptide than the label promised in one case, and a spread of more than double between identically labelled bottles in the other.

Key findings at a glance

  • No approval anywhere in the world. Australia names Melanotan II as prescription-only while no approved product exists, and the FDA lists it among the substances that carry identified safety risks [1], [2].
  • The entire human record is four papers and fewer than 25 men. All of them came from one group at the University of Arizona between 1996 and 2000, and nobody has repeated the work since [3], [4].
  • Skin colour was measured in three people. Two of the three showed more pigment in the face, upper body and buttocks a week after the last dose [3].
  • The sexual effect was the stronger finding. Seventeen of 20 men developed an erection without any sexual stimulation, and 12.9 percent of participants had severe nausea [4].
  • The FDA names four serious events from case reports. They are melanoma, brain swelling known as PRES, a stimulant-like poisoning and a painful prolonged erection [1].
  • The vials rarely hold what the label says. A Danish laboratory measured 4.32 to 8.84 mg where 10 mg was promised, and the Australian regulator measured 22 to 54 mg in nasal sprays labelled 30 mg [5], [6].
  • Banned in sport at all times. It is not named on the 2026 list, but the catch-all opening section covers substances whose development was discontinued [7].
  • The one entry in the trial registry calls itself an example. Its own summary opens with the words "This example interventional study record", and the same sponsor name sits behind a second record that calls itself fictional [8].

What it is

Melanotan II is a ring-shaped peptide of seven building blocks. It copies a short stretch of the body's own alpha-melanocyte-stimulating hormone, the signal that tells pigment cells to make more melanin. Four deliberate chemical changes make it stronger and harder for the body to break down [9], [10].

Unlike many grey-market peptides, it has a real development history. Chemists and anatomists at the University of Arizona in Tucson designed it in the 1980s, and the name comes from that academic programme rather than from a sales catalogue [9]. The programme produced three related molecules, and this is the only one that was never approved for anything [11].

Quick facts

FieldValueRef
Common namesMelanotan II, MT-II, MT-2[10]
ClassLab-made ring-shaped peptide of seven building blocks[9]
SequenceAc-Nle-cycloAsp-His-D-Phe-Arg-Trp-Lys-NH2[9]
The hormone it copiesAlpha-melanocyte-stimulating hormone, positions 4 to 10[9]
Formula and massC50H69N15O9, 1024.2 g/mol[10]
How long it lasts in peopleNever published[12]
StatusNot approved in any country[1], [2]
Who developed itUniversity of Arizona, Tucson, in the 1980s[9]
CAS registry number121062-08-6[10]
UNIIUPF5CJ93X7[10]
PubChem CID92432[10]

Melanotan II: what the studies show, status and safety

How it works

Nothing about how it works has been measured properly in people, so every point below rests on cells, on animals or on four small studies from the 1990s [13].

  • It is thought to switch on several melanocortin receptors at once. The body has five of these receivers, and the peptide is thought to act on more than one. That is why its effects are not confined to skin colour [13], [11].
  • The pigment effect is attributed to the receptor on pigment cells. That is a reasonable reading of the receptor family. The best available laboratory study, however, tested three of the five receivers and not the one on pigment cells [13].
  • The brain effects may come from receptors in the appetite centres. Reduced appetite, erection, nausea and a stretching and yawning reflex are attributed to receivers in the hypothalamus and brainstem, mostly on the basis of rodent work [14], [11].
  • The ring is what makes it strong. Closing the molecule into a 23-membered ring raised its potency about a hundredfold in a lizard skin test and made it resistant to digestive enzymes [9], [15].
  • At least one effect bypasses the intended target completely. In mice, the sharp drop in body temperature persisted when any one of four melanocortin receptors was missing, and disappeared only in animals without mast cells. It runs through histamine released by those cells, acting on the H1 receptor [16].

That last point matters for the marketing picture. A molecule described as a clean tanning peptide turns out, in the one experiment that asked the question, to act partly through a completely different system [16].

What the trials found

There are four human papers, all from one group, all in men, and none since the year 2000 [4]. Everything else is animal or laboratory work.

Skin colour

Human pilot study Three healthy men received the peptide under the skin on alternating days for two weeks, with salt water on the days in between. Two of the three showed more pigment in the face, upper body and buttocks one week after the last dose, measured by reflectance and confirmed by eye. That is the only published measurement of the pigment effect of Melanotan II in people [3].

Erection and sexual desire

Human phase 1 Two double-blind crossover studies enrolled ten men each, one group with no physical cause for their erectile problems and one with physical risk factors. Pooled across the 20 men, 17 developed an erection without any sexual stimulation [4].

In the first group, 8 of 10 men had a clinically visible erection. Peak firmness above 80 percent lasted 38.0 minutes on the peptide against 3.0 minutes on placebo, a difference too large to be chance (p = 0.0045) [17].

In the second group the same measure gave 45.3 minutes against 1.9 minutes (p = 0.047) [18]. Pooled across both studies, the authors reported a mean of 41 minutes above that threshold [4].

Increased sexual desire was reported after 13 of 19 doses of the peptide (68 percent), against 4 of 21 placebo doses (19 percent), again beyond chance (p < 0.01) [4]. These were the effects the developers pursued, and they are the reason a modified version of the molecule went on to become an approved drug for something else entirely [11].

Nausea alongside those effects

Human phase 1 Severe nausea occurred in 12.9 percent of participants at the dose used in both studies [4]. In the group with physical risk factors it followed 4 of 19 injections [18]. In the pilot study, mild nausea appeared at most dose levels, together with drowsiness and fatigue at the highest one [3].

Appetite and body fat in animals

Animal data In rats given the peptide directly into a brain ventricle, the first application cut food intake by 30 percent, and the effect faded within five days. After a pause, a fresh supply worked again just as strongly, while uninterrupted delivery did not [14].

By day 30, body fat had fallen by 80 percent in both treated groups. The appetite receiver the peptide acts on in the hypothalamus (MC4) was 25 percent less abundant [14]. No study has examined appetite or weight with this peptide in people [4].

Melanoma and moles

Case reports only Several reports describe melanoma or melanoma in situ in people who had used melanotan, and many more describe new moles appearing and existing moles turning darker. In one German case, new moles and darkening appeared within 24 hours of a single dose [19], [20].

A review of eruptive moles covering 93 papers and 179 patients attributed 41 percent of cases to immune-suppressing drugs, chemotherapy or melanotan. Across all 179 patients, 16 percent had at least one abnormal mole confirmed under the microscope, and five melanomas were reported [21].

None of this proves cause and effect. Almost every reported case involved heavy ultraviolet exposure as well, usually from sunbeds, and a 2017 review states plainly that conclusive evidence linking the two is lacking [22].

Protection from the sun

No evidence No study shows that Melanotan II protects human skin against ultraviolet damage or skin cancer. That claim was the exact reason the FDA acted against an American seller in 2007, and the Australian regulator answers it directly: no tan, fake or real, will protect skin against damage from sun exposure [23], [24].

A finding that points the other way

Animal data In mice with established melanoma, the peptide applied to the skin slowed tumour progression and blocked the movement and invasion of melanoma cells in the dish [25]. That is a mouse model with a preparation rubbed on the skin, and it is not evidence of safety in people. It does show how contradictory this field is.

What is still unknown

  • How the body handles it. There is no published half-life, no absorption figure and no elimination data for people. Everything comes from rats and rabbits [12], [26].
  • What happens beyond two weeks. The longest documented use under study conditions was two weeks. Use over months has never been observed under controlled conditions [3].
  • Whether it causes cancer. No cancer study exists. The case reports point one way and a mouse experiment points the other [22], [25].
  • What it does in women. Every human data point comes from adult men, while the dermatology case reports overwhelmingly concern young women [4], [20].
  • How it interacts with other drugs. Nothing has been studied, although forum research describes people combining several substances [27].

Side effects and safety

The safety picture rests on a handful of study participants and a growing pile of case reports. The FDA summarises it by naming four serious events from the published literature: melanoma, brain swelling known as PRES, a stimulant-like poisoning and a painful prolonged erection [1].

  • Nausea, drowsiness, flushing and loss of appetite. These appeared in the human studies of the 1990s at the doses tested, with severe nausea in 12.9 percent of participants [3], [4].
  • A stimulant-like poisoning with muscle breakdown. A 39-year-old man injected 6 mg bought online. Two hours later his heart ran at 130 to 146 beats a minute, with dilated pupils, tremor and sweating. His muscle enzyme rose from 1,760 to 17,773 units within 12 hours, and he spent three days in intensive care. Mass spectrometry confirmed the substance as Melanotan II [28].
  • Painful prolonged erection. Three cases are published. Two needed invasive treatment, one of them surgery, and in one case erectile function had still not returned four weeks later [29], [30], [31].
  • Brain swelling and a kidney infarct. PRES was reported in a letter to a medical journal, and a Swedish team described a kidney infarct they considered most likely due to the peptide [32], [33].
  • New and darkening moles. This is the most frequently reported dermatological effect, with cases from at least seven countries. A German study using sequential video dermoscopy recorded that the changes made it harder to tell a mole from a melanoma [34], [19].
  • Pigment in the mouth and other skin reactions. Reported effects include brown gum pigmentation that persisted three months after stopping, nail pigmentation, patches of lost colour, and ulcerated wounds at injection sites diagnosed as pyoderma gangrenosum [35], [36].
  • Reports collected by the authorities. The British regulator counted 18 reports covering 74 separate suspected effects, including stomach, heart, blood and eye problems [37]. Suspected reports are not proof of cause, and reporting is heavily incomplete for a product sold illegally.

What is actually in the products

Two independent laboratories have measured grey-market goods, and both found the contents at odds with the label.

Measured content against the label
Vial label
10mg
Vial, lowest measured
4.32mg
Vial, highest measured
8.84mg
Nasal spray label
30mg
Nasal spray, lowest of five
22mg
Nasal spray, highest of five
54mg

A Danish laboratory measured three shops selling vials labelled 10 mg. The Australian regulator measured five nasal sprays labelled 30 MG. Sources [5] and [6].

The Danish work also found unknown impurities of 4.1 to 5.9 percent in vials from two of the three shops [5]. With products sold as TB-500, laboratories often found no peptide at all. Here the problem is not absence but quantity: the peptide is there, in an amount nobody can predict [5], [6].

An Italian forensic laboratory characterised eight police-seized samples in 2021, taken alongside anabolic steroids and stimulants. It had to identify the compounds without reference standards, which says something about how far outside regulated pharmacy this material sits [38].

Nothing is known about pregnancy, about children, or about people whose kidneys or liver work poorly, because nobody has looked. Shared needles carry the usual risk of blood-borne infection, a point British dermatologists raised as early as 2010 [39].

Doses used in studies

The doses below are simply what the cited studies gave, listed so that the results can be understood. They are not advice on how to use anything. The human figures come from studies run under medical supervision in the 1990s, and the amounts circulating on the grey market are far larger.

StudyModelDoseRouteFrequencyDurationRef
Dorr 1996, pilot phase 1Human, 3 healthy men0.01 mg/kg rising in 0.005 mg/kg steps to 0.03 mg/kg in two men and 0.025 mg/kg in oneUnder the skinMonday to Friday, salt water in between2 weeks[3]
Wessells 1998, no physical causeHuman, 10 men0.025 mg/kgUnder the skinSingle doses in crossover6 hours of observation[17]
Wessells 2000, physical risk factorsHuman, 10 men0.025 mg/kgUnder the skinTwo doses of each, peptide and vehicle6 hours of observation[18]
Ugwu 1994, how the body handles itRat0.3 mg/kgInto a veinSingle doseOnce[12]
Giuliano 2005, erectile pressureRat, awake and anaesthetised0.1, 0.3 and 1 mg/kgInto a veinSingle dosesMeasured after dosing[40]
Zhang 2010, appetite and fatRatNot given in numbers in the abstractInto a brain ventricleContinuous, then intermittent30 days[14]

The pilot study proposed 0.025 mg/kg a day for further phase 1 work under medical supervision. That figure describes a plan for the next study, not a dose for anybody else [3]. For comparison, the man who developed muscle breakdown injected 6 mg at once, which for an 80 kg adult is roughly three times that daily figure [28].

Development and approval status

From an Arizona laboratory to a regulatory problem

  1. 1989The molecule is designed and publishedUniversity of Arizona; about a hundredfold the potency of the natural hormone in a lizard skin test, ref [9]
  2. 1996First study in people, three participantsPigment measured in two of three, plus nausea and spontaneous erections, ref [3]
  3. 1998-2000Two crossover studies in 20 men with erectile problemsThe last human research on this molecule to date, ref [4]
  4. 2000sDevelopment moves to two other moleculesMelanotan I for light protection and bremelanotide for sexual desire; both were approved, this one was not, ref [11]
  5. 2007FDA acts against an American sellerMarketed as protection against skin cancer; the case later ended in a conviction and a permanent debarment, ref [23]
  6. 2008-2013Denmark, the United Kingdom and Germany warn the publicBritain counts 74 suspected adverse effects and shuts down 72 websites, refs [41], [37], [42]
  7. 2015A Danish laboratory measures what is in the vials4.32 to 8.84 mg where 10 mg was promised, ref [5]
  8. 2025Australia publishes a public warningIllegal to supply or advertise, in any form, ref [24]
  9. 2026Fines, and a laboratory result on nasal sprays27 infringement notices totalling 101,412 dollars; sprays labelled 30 MG hold 22 to 54 mg, refs [43], [6]

Three molecules came out of the same Arizona programme, and their fates diverged. Melanotan I became an approved drug in Europe for a rare light-sensitivity disease [44]. Bremelanotide became an approved drug in the United States for low sexual desire in women [45]. Melanotan II, the middle one, was left behind after the phase 1 studies [11].

The published record does not state why in a single sentence. What it does show is that the pigment effect, the nausea and the erection could not be separated from one another [11], [4]. That is a plausible reason, offered here as a reading rather than a fact.

MarketStatusNoteRef
United StatesNot approvedNamed on the compounding safety-risk list[1]
European UnionNot approvedNo assessment report exists—
GermanyNot approvedAuthority advised against use in 2010[42]
United KingdomNot approvedAn unlicensed medicine; selling it is unlawful[37]
AustraliaRestrictedPrescription-only, with no approved product[2]
DenmarkNot approvedTwo public warnings[41]
NorwayNot approvedImport by individuals is unlawful[46]

Two lines rest on original legal documents. The Australian entry comes from the poisons instrument in force since June 2026, which lists Melanotan II and afamelanotide as two separate substances [2]. The American entry comes from the FDA compounding page as it stood on 22 April 2026 [1].

For Switzerland and Canada no authority document could be retrieved on 6 September 2026, so those markets are left out rather than guessed at. One Australian detail is worth naming: unlike BPC-157 and TB-500, Melanotan II is not in the appendix that makes possession without authority unlawful [2].

Anti-doping

Melanotan II is banned in sport at all times, in and out of competition, but it does not appear by name anywhere on the 2026 Prohibited List. A full-text search of the official version returns no hit for melanotan [7].

It is caught by the opening section instead. That section covers any substance not addressed elsewhere on the list and without approval from any governmental health authority. It names discontinued development compounds explicitly, and Melanotan II fits both halves [7].

Substances in that section count as specified. That affects how a sanction is weighed, but not whether the ban applies.

The American college sports association does not name it either. Its list carries the same kind of catch-all note: anything chemically or pharmacologically related to the listed classes is also banned [47].

Methods for detecting the peptide have existed since the 1990s, and were extended to seized street material in 2021 [26], [38]. The wider picture is at peptides banned in sport.

Compared with related peptides

PeptideWhat it isApprovalHuman evidenceStrongest result in its own study
Melanotan IIRing-shaped peptide of 7 building blocksNone anywhere4 papers, fewer than 25 men, 1996 to 200017 of 20 men had an erection without stimulation [4]
Melanotan IStraight-chain peptide of 13 building blocks, known as afamelanotideApproved in the EU as an implant for a rare light-sensitivity diseaseRegistration trial with 93 patients116 hours of pain-free sun exposure over six months against 61 on placebo [44]
BremelanotideMelanotan II with one chemical group swappedApproved in the US for low sexual desire in premenopausal womenTwo 24-week trials with 1,247 womenNausea in 40 percent, and patchy skin darkening in 1 percent [45]
KPVThe last three building blocks of the same parent hormoneNoneNone; the FDA states it found no human exposure dataNo human result exists [48]

These four are relatives, not equivalents. Melanotan I and bremelanotide both went through full regulatory assessment and carry approved labels, which is precisely what Melanotan II lacks [44], [45].

The bremelanotide label is worth reading for one reason. It holds the only officially assessed safety data in this whole family.

Even there the label limits how often it may be used. Patchy darkening of the face, gums and breasts still occurred in 1 percent of women, and resolution was not confirmed in every case [45]. Those figures belong to bremelanotide, a different molecule, and cannot be carried over to Melanotan II.

Common misconceptions

  • "Melanotan I and Melanotan II are the same thing." They are two molecules: 13 building blocks in a straight chain against seven in a ring, 1646.8 g/mol against 1024.2. Australia lists them separately. The widely quoted tanning studies by Dorr from 2000 and 2004 tested Melanotan I [49], [2], [50].
  • "Melanotan II is PT-141." PT-141 is the development code for bremelanotide, which is derived from Melanotan II but differs at the end of the chain, and it is the one that was approved. The two are separate entries in the chemical databases [51], [45].
  • "The Barbie peptide is a substance name." It is a press label that arose in Scandinavian newspapers around 2007 and is applied to both melanotans indiscriminately. Dermatologists made the confusion the title of a journal letter: what exactly is meant by melanotan? [52]
  • "It is just a tanning product and the rest are rare side effects." In the studies that exist, the sexual and gastrointestinal effects were more consistent than the pigment change. Erection was the main measured outcome in two of the four papers [3], [4].
  • "Melanotan II protects against sunburn or skin cancer." No study supports that for this molecule. It was the claim the FDA acted on in 2007 and the Norwegian regulator banned a website from repeating in 2026 [23], [46].
  • "The nasal spray is the gentler option." The form changes nothing about the legal status and makes the amount less predictable. Five sprays labelled 30 MG held between 22 and 54 mg, and a mucosal melanoma has been reported after nasal spray use [6], [53].
  • "A clinical trial of Melanotan II is running." The single registry entry describes itself in its own summary as an example record. It shares a sponsor name with a TB-500 record that calls itself fictional outright [8].
  • "The melanoma cases prove it causes cancer." They do not, in either direction. All are single cases with heavy sunbed use alongside, and a mouse experiment points the opposite way. What is documented is that moles darken and become harder to assess [22], [25], [34].

Frequently asked questions

What is Melanotan II?

Melanotan II is a lab-made peptide of seven building blocks arranged in a ring. It copies part of the body's own alpha-melanocyte-stimulating hormone, the signal that tells pigment cells to make melanin. Chemists at the University of Arizona designed it in the 1980s, and it has never been approved as a medicine anywhere.

Is Melanotan II approved in any country?

No. There is no approval in any country and no assessment report from any medicines agency. Australia lists it as prescription-only while no approved product exists, which makes any supply to consumers unlawful. The United States, the United Kingdom, Germany, Denmark and Norway have all issued public warnings.

What did the human studies of Melanotan II actually show?

Four papers exist, all from one group at the University of Arizona between 1996 and 2000, covering fewer than 25 men. In the pilot study of three men, two showed more pigment a week after the last dose. In the two erectile studies, 17 of 20 men developed an erection without sexual stimulation, and 12.9 percent of participants had severe nausea.

Is Melanotan II the same as Melanotan I or bremelanotide?

No, they are three different molecules. Melanotan I, also called afamelanotide, is a straight chain of 13 building blocks and is approved in Europe for a rare light-sensitivity disease. Bremelanotide differs from Melanotan II at one end of the molecule and is approved in the United States for low sexual desire. Only Melanotan II remains unapproved.

Does Melanotan II protect the skin from the sun?

No study shows that. That exact claim triggered the FDA action against an American seller in 2007 and a Norwegian ban on a website in 2026. The Australian regulator puts it plainly: no tan, fake or real, will protect skin against damage from sun exposure.

Does Melanotan II cause melanoma?

That cannot be answered with the evidence available. Several case reports describe melanoma in people who used melanotan, but almost all of them also used sunbeds, and no cancer study exists. What is documented is that existing moles darken, new ones appear, and the change makes it harder to tell a mole from a melanoma.

What is actually inside products sold as Melanotan II?

Rarely the amount on the label. A Danish laboratory found 4.32 to 8.84 mg in vials all claiming 10 mg, plus unknown impurities of up to 5.9 percent in two of three shops. The Australian regulator measured 22 to 54 mg in five nasal sprays that all carried the same 30 MG label.

Is a Melanotan II nasal spray safer than an injection?

No. The form changes nothing about the legal status, and the amount taken up depends on spray technique, so it is less controllable rather than more. The Australian laboratory result showed a spread of more than double between identically labelled bottles, and a mucosal melanoma has been reported after nasal spray use.

Is Melanotan II banned in sport?

Yes, at all times, in and out of competition. It is not named on the 2026 Prohibited List, but the opening section covers any substance with no approval from a health authority anywhere, including discontinued development compounds. Melanotan II meets both conditions, so the absence of its name is not a loophole.

Is there a clinical trial of Melanotan II running?

No. One entry in the ClinicalTrials.gov registry names Melanotan II for vitiligo. Its own summary opens by calling itself an example record, and the registry does not treat it as an FDA-regulated drug study. The same sponsor name appears on a second record that describes itself as fictional. Once that entry is set aside, no genuine study of this peptide is registered anywhere.

Sources

  1. US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks; entry "Melanotan II" under bulk drug substances nominated but withdrawn: "Published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism." Content current as of 22 April 2026, retrieved 6 September 2026. https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
  2. Therapeutic Goods (Poisons Standard—June 2026) Instrument 2026, authorised version F2026L00633, registered 28 May 2026. Schedule 4 entry "MELANOTAN II.", index cross reference to alpha-melanocyte stimulating hormone, and a separate Schedule 4 entry "AFAMELANOTIDE." cross-referenced to Melanotan I. Appendix D clause 5 checked in full: no melanotan entry. Full text extracted 6 September 2026.
  3. Dorr RT, Lines R, Levine N, Brooks C, Xiang L, Hruby VJ, Hadley ME (1996). Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sciences 58(20):1777-84. PMID 8637402 · DOI 10.1016/0024-3205(96)00160-9
  4. Wessells H, Levine N, Hadley ME, Dorr R, Hruby V (2000). Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II. International Journal of Impotence Research 12 Suppl 4:S74-9. PMID 11035391 · DOI 10.1038/sj.ijir.3900582
  5. Breindahl T, Evans-Brown M, Hindersson P, McVeigh J, Bellis M, Stensballe A, Kimergard A (2015). Identification and characterization by LC-UV-MS/MS of melanotan II skin-tanning products sold illegally on the Internet. Drug Testing and Analysis 7(2):164-72. PMID 24771717 · DOI 10.1002/dta.1655
  6. Therapeutic Goods Administration. Safety advisory: Melanotan II tanning peptide products found to be inconsistently dosed, August 2026. "Our laboratory tested 5 nasal spray products labelled 'Pure Tans Triple Strength 30 MG'. We found the estimated amount of Melanotan II ranged between 22 mg and 54 mg based on the labelled volume of 20 mL per bottle." Advisory page not retrievable on 6 September 2026; wording taken from the agency's own LinkedIn channel of 19 August 2026 and confirmed by RACGP newsGP, 18 August 2026, and 7NEWS, 18 August 2026.
  7. World Anti-Doping Agency. The 2026 Prohibited List, section S0 "Non-approved substances", class header and operative sentence; official text verified against the Austrian promulgation BGBl. III No. 219/2025 of 30 December 2025. A full-text search for melanotan, melano and MSH returned no hit. Retrieved 6 September 2026. https://www.wada-ama.org/en/prohibited-list
  8. ClinicalTrials.gov. NCT07437560, "Melanotan II (MT-II) as an adjunct to NB-UVB phototherapy for repigmentation in stable nonsegmental vitiligo", sponsor Hudson Biotech. The brief summary states: "This example interventional study record describes a randomized Phase 2 clinical trial evaluating investigational Melanotan II (MT-II) …"; the field isFdaRegulatedDrug is set to false. The same sponsor name appears on NCT07487363, whose brief summary begins "This fictional study is an example of a ClinicalTrials.gov-style record". Both records retrieved via API v2 on 6 September 2026. https://clinicaltrials.gov/study/NCT07437560
  9. Al-Obeidi F, Castrucci AM, Hadley ME, Hruby VJ (1989). Potent and prolonged acting cyclic lactam analogues of alpha-melanotropin: design based on molecular dynamics. Journal of Medicinal Chemistry 32(12):2555-61. PMID 2555512 · DOI 10.1021/jm00132a010
  10. PubChem. Compound CID 92432, Melanotan II; CAS 121062-08-6, UNII UPF5CJ93X7, C50H69N15O9, 1024.2 g/mol, InChIKey JDKLPDJLXHXHNV-MFVUMRCOSA-N. Retrieved via PUG-REST on 6 September 2026. https://pubchem.ncbi.nlm.nih.gov/compound/92432
  11. Hadley ME, Dorr RT (2006). Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides 27(4):921-30. PMID 16412534 · DOI 10.1016/j.peptides.2005.01.029
  12. Ugwu SO, Blanchard J, Nguyen LD, Hadley ME, Dorr RT (1994). A comparison of HPLC and bioassay methods for plasma melanotan-II (MT-II) determination: application to a pharmacokinetic study in rats. Biopharmaceutics and Drug Disposition 15(5):383-90. PMID 7981427
  13. Bednarek MA, Silva MV, Arison B, MacNeil T, Kalyani RN, Huang RR, Weinberg DH (1999). Structure-function studies on the cyclic peptide MT-II, lactam derivative of alpha-melanotropin. Peptides 20(3):401-9. PMID 10447101 · DOI 10.1016/s0196-9781(99)00048-0. Binding and activation were tested at human MC3, MC4 and MC5 receptors, not at MC1R; no complete affinity table across all five receptors is available from a primary source.
  14. Zhang Y, Collazo R, Gao Y, Li G, Scarpace PJ (2010). Intermittent MTII application evokes repeated anorexia and robust fat and weight loss. Peptides 31(4):639-43. PMID 20034526
  15. Hadley ME, Marwan MM, al-Obeidi F, Hruby VJ, Castrucci AM (1989). Linear and cyclic alpha-melanotropin [4-10]-fragment analogues that exhibit superpotency and residual activity. Pigment Cell Research 2(6):478-84. PMID 2557603
  16. Jain S, Panyutin A, Liu N, et al. (2018). Melanotan II causes hypothermia in mice by activation of mast cells and stimulation of histamine 1 receptors. American Journal of Physiology: Endocrinology and Metabolism 315(3):E357-E366. PMID 29812984
  17. Wessells H, Fuciarelli K, Hansen J, Hadley ME, Hruby VJ, Dorr R, Levine N (1998). Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. Journal of Urology 160(2):389-93. PMID 9679884
  18. Wessells H, Gralnek D, Dorr R, Hruby VJ, Hadley ME, Levine N (2000). Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Urology 56(4):641-6. PMID 11018622 · DOI 10.1016/s0090-4295(00)00680-4
  19. Schulze F, Erdmann H, Hardkop LH, Anemuller W, Rose C, Zillikens D, Fischer TW (2014). Eruptive naevi and darkening of pre-existing naevi 24 h after a single mono-dose injection of melanotan II. European Journal of Dermatology 24(1):107-9. PMID 24334249 · DOI 10.1684/ejd.2013.2227
  20. Hjuler KF, Lorentzen HF (2014). Melanoma associated with the use of melanotan-II. Dermatology 228(1):34-6. PMID 24355990 · DOI 10.1159/000356389. Further melanoma case reports: PMID 21564053 (Belgium 2011), PMID 22724573 (Australia 2012), PMID 42328529 (five melanomas in situ alongside sunbed and anabolic hormone use, 2026).
  21. Burian EA, Jemec GBE (2019). Eruptive melanocytic nevi: a review. American Journal of Clinical Dermatology 20(5):669-82. PMID 31119650 · DOI 10.1007/s40257-019-00444-8. Systematic bibliographic review of 93 publications and 179 patients.
  22. Habbema L, Halk AB, Neumann M, Bergman W (2017). Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. International Journal of Dermatology 56(10):975-80. PMID 28266027 · DOI 10.1111/ijd.13585
  23. US Food and Drug Administration. Warning letter of 30 August 2007 to Melanocorp, Inc., Hendersonville, Tennessee, announced publicly on 5 September 2007; quotation from Steven Galson, Director of the Center for Drug Evaluation and Research: "This product is being mislabeled, marketed and sold illegally as a preventative against skin cancer and as a tanning agent." The subsequent debarment document, Docket No. FDA-2015-N-4169, records continued distribution, a criminal conviction under 18 U.S.C. 371 and a permanent debarment. https://www.fda.gov/media/128834/download
  24. Therapeutic Goods Administration. Don't risk using tanning products containing melanotan, 24 January 2025, retrieved 6 September 2026. "No tan, fake or real, will protect skin against damage from sun exposure." "These restrictions apply regardless of whether it is a spray, a tablet, an injection, a cream or in any other form." https://www.tga.gov.au/news/blog/dont-risk-using-tanning-products-containing-melanotan
  25. Wu JC, Tsai HE, Hsiao YH, Wu JS, Wu CS, Tai MH (2020). Topical MTII therapy suppresses melanoma through PTEN upregulation and cyclooxygenase II inhibition. International Journal of Molecular Sciences 21(2):681. PMID 31968661 · DOI 10.3390/ijms21020681
  26. Mock S, Shen X, Tamvakopoulos C (2002). Determination of melanotan-II in rat plasma by liquid chromatography/tandem mass spectrometry. Rapid Communications in Mass Spectrometry 16(22):2142-7. PMID 12415547 · DOI 10.1002/rcm.847
  27. Gilhooley E, Daly S, McKenna D (2021). Melanotan II user experience: a qualitative study of online discussion forums. Dermatology 237(6):995-9. PMID 34464955 · DOI 10.1159/000514492. 623 posts by 205 participants from British and Irish forums.
  28. Nelson ME, Bryant SM, Aks SE (2012). Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Clinical Toxicology 50(10):1169-73. PMID 23121206 · DOI 10.3109/15563650.2012.740637. The injected material was confirmed as Melanotan II by mass spectrometry against a purchased standard.
  29. Devlin J, Pomerleau A, Foote J (2013). Melanotan II overdose associated with priapism. Clinical Toxicology 51(4):383. PMID 23537392 · DOI 10.3109/15563650.2013.784775. No abstract is held at PubMed; title and attribution verified only.
  30. Dreyer BA, Amer T, Fraser M (2019). Melanotan-induced priapism: a hard-earned tan. BMJ Case Reports 12(2):e227644. PMID 30796078
  31. Mallory CW, Lopategui DM, Cordon BH (2021). Melanotan tanning injection: a rare cause of priapism. Sexual Medicine 9(1):100298. PMID 33460908
  32. Kaski D, Stafford N, Mehta A, Jenkins IH, Malhotra P (2013). Melanotan and the posterior reversible encephalopathy syndrome. Annals of Internal Medicine 158(9):707-8. PMID 23648958. No abstract is held at PubMed; title and attribution verified only.
  33. Peters B, Hadimeri H, Wahlberg R, Afghahi H (2020). Melanotan II: a possible cause of renal infarction: review of the literature and case report. CEN Case Reports 9(2):159-61. PMID 31953620
  34. Mang R, Krahl D, Assmann T (2012). Dermoskopische Veranderungen melanozytarer Navi unter Anwendung von Melanotan II. Der Hautarzt 63(11):880-4. PMID 23052015 · DOI 10.1007/s00105-012-2420-1. Sequential video dermoscopy before and during use; the recorded changes made it harder to distinguish a naevus from a melanoma.
  35. Bonchev A (2026). Changes in oral mucosa associated with Melanotan II injections: a case report. Life (Basel) 16(2):265. PMID 41752902 · DOI 10.3390/life16020265. Related pigmentation reports: PMID 22182016 (transverse melanonychia) and PMID 42212476 (depigmented patches; no abstract held at PubMed).
  36. Dickson D, Hlaing Htwe S (2025). Pyoderma gangrenosum secondary to melanotan. Cureus 17(12):e98297. PMID 41487785 · DOI 10.7759/cureus.98297
  37. Medicines and Healthcare products Regulatory Agency. Press release of 17 November 2008 and news release of 29 August 2013 warning against melanotan sold as an unlicensed medicine; the 2013 release reports 18 reports covering 74 separate suspected adverse reactions and 72 websites closed within three months. MHRA primary documents were not retrievable on 6 September 2026; the wording is documented by five independent secondary reports (BBC News, The Guardian, Nursing Times, Herald Scotland, Lexology).
  38. Mestria S, Odoardi S, Frison G, Strano Rossi S (2021). LC-HRMS characterization of the skin pigmentation and sexual enhancers melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs. Drug Testing and Analysis 13(4):876-82. PMID 33245851 · DOI 10.1002/dta.2986
  39. Langan EA, Nie Z, Rhodes LE (2010). Melanotropic peptides: more than just Barbie drugs and sun-tan jabs? British Journal of Dermatology 163(3):451-5. PMID 20545686 · DOI 10.1111/j.1365-2133.2010.09891.x
  40. Giuliano F, Rossler AS, Clement P, Droupy S, Alexandre L, Bernabe J (2005). The use of telemetry technology to test the proerectile effect of melanotan-II (MT-II) in conscious rats. European Urology 48(1):145-51. PMID 15967265 · DOI 10.1016/j.eururo.2005.02.023
  41. Laegemiddelstyrelsen (Danish Medicines Agency). Warning against the product Melanotan, 8 August 2008 (English version 11 August 2008): "The product is marketed as a product that increases pigmentation … implying that it may prevent skin cancer. However, this effect has not been documented." Repeated on 20 June 2011. https://laegemiddelstyrelsen.dk/en/pharmacies/medicines-imported-from-abroad/warnings-against-products/warning-against-the-product-melanotan/
  42. Bundesinstitut für Arzneimittel und Medizinprodukte. Press release 14/10 of 28 October 2010, advising strongly against obtaining and cosmetically using melanotan-containing products from indeterminate internet sources, and noting risks to the cardiovascular system, the digestive tract and skin colour. The agency confirmed to Stiftung Warentest on 11 July 2026 that the warning still stands. https://www.bfarm.de/SharedDocs/Pressemitteilungen/DE/2010/pm14-2010.html
  43. Therapeutic Goods Administration. Individual issued 27 infringement notices for allegedly supplying Melanotan II, media release of 21 May 2026, retrieved 6 September 2026. The notices totalled 101,412 Australian dollars and were paid in May 2026; no product containing Melanotan II is on the Australian Register of Therapeutic Goods. https://www.tga.gov.au/news/media-releases/individual-issued-27-infringement-notices-allegedly-supplying-melanotan-ii
  44. European Medicines Agency. Scenesse (afamelanotide) European public assessment report, retrieved 6 September 2026. Implant for erythropoietic protoporphyria, orphan designation of 8 May 2008; registration trial in 93 patients reporting an average of 116 hours of pain-free direct sun exposure over six months against 61 hours on placebo. This concerns Melanotan I, not Melanotan II. https://www.ema.europa.eu/en/medicines/human/EPAR/scenesse
  45. US Food and Drug Administration. Vyleesi (bremelanotide) news release of 21 June 2019 and prescribing information, NDA 210557, revised June 2019. Approved for hypoactive sexual desire disorder in premenopausal women on the basis of two 24-week randomised trials with 1,247 participants; warnings include focal hyperpigmentation in 1 percent of patients taking up to eight doses a month, which did not resolve in all cases, and nausea in 40 percent. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf
  46. Direktoratet for medisinske produkter (Norway). Advarer mot peptider til injeksjon, 5 May 2026, and the enforcement decision Vedtak om pålegg om stans av ulovlig reklame for melanotan og retatrutid, ref. 25/34799-15, which quotes the advertising claim "Beskytter mot UV-skader". Norwegian customs stopped close to 2,500 units of melanotan between 2023 and May 2025. https://www.dmp.no/nyheter/advarer-mot-peptider-til-injeksjon
  47. National Collegiate Athletic Association. 2026-27 NCAA banned substances. A full-text check on 6 September 2026 returned no melanotan entry; the list carries the note: "This is neither a complete nor exhaustive list. Any substance chemically/pharmacologically related to these classes is also banned."
  48. US Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks; entry "KPV": "FDA has not identified any human exposure data on drug products containing KPV administered via any route of administration." Content current as of 22 April 2026, retrieved 6 September 2026.
  49. PubChem. Compound CID 16197727, afamelanotide (Melanotan I); C78H111N21O19, 1646.8 g/mol. Retrieved 6 September 2026. https://pubchem.ncbi.nlm.nih.gov/compound/16197727
  50. Studies frequently cited as melanotan evidence that in fact tested Melanotan I: Dorr RT et al. (2000), Photochemistry and Photobiology 72(4):526-32, PMID 11045725; Dorr RT et al. (2004), Archives of Dermatology 140(7):827-35, PMID 15262693; Fitzgerald LM et al. (2006), Peptides 27(2):388-94, PMID 16293341.
  51. PubChem. Compound CID 9941379, bremelanotide; C50H68N14O10, 1025.2 g/mol. The formula differs from Melanotan II by the exchange of the C-terminal carboxamide for a free acid. Retrieved 6 September 2026. https://pubchem.ncbi.nlm.nih.gov/compound/9941379
  52. Langan EA, Rhodes LE (2011). Melanotropic peptides: what exactly is meant by melanotan? Acta Dermato-Venereologica 91(3):377. PMID 21547334 · DOI 10.2340/00015555-1130
  53. Yassin Alsabbagh A, Bhujel N, Singh RP (2025). Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma? International Journal of Oral and Maxillofacial Surgery 54(9):806-8. PMID 40210573 · DOI 10.1016/j.ijom.2025.03.014

Cite this page

The facts on this page were checked on 6 September 2026. The legal and laboratory statements rest on original documents from the American, Australian, German, Danish and Norwegian authorities, and every case report is marked as such.

myPeptides Research & Editing. (2026). Melanotan II: what the studies show, status and safety. Version 1.0, 6 September 2026. myPeptides Peptide Register. Retrieved from https://mypep.app/peptides/melanotan-ii

How pages in this register are compiled and graded is described under methodology; the full register is at peptides.

VersionDateChange
1.02026-09-06Initial publication

Last verified: 6 September 2026. Next review: on publication of any new human study, on a change in the anti-doping classification, or on a change in the FDA or Poisons Standard entries.

Identifiers

IdentifierValue
CAS number121062-08-6
PubChem CID92432
UNIIUPF5CJ93X7
InChIKeyJDKLPDJLXHXHNV-MFVUMRCOSA-N
ChEMBLCHEMBL430239
WikidataQ423855
Molecular formulaC50H69N15O9
Molecular weight1024.2
SequenceAc-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2

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myPeptides Research & Editing (2026). Melanotan II: what the studies show, status and safety (Version 1.0). myPeptides. https://mypep.app/peptides/melanotan-ii

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Last reviewed: September 2026

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