Reviewed & approved by Dr. Nova Reyes · Last checked 2026-10-15. ← Back to Evidence Library

Melanotan II: what the evidence says

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

What "No human data" means here: for skin-cancer prevention and other claimed uses, we found nothing at all in human trials.

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What is it?

Melanotan II is a short, ring-shaped peptide based on alpha-MSH. Unlike the approved drugs related to it (below), it is not selective: it switches on several melanocortin receptors at once (MC1R on pigment cells, MC3R and MC4R in the brain, and others). That is why one injection can darken skin, cause erections, cut appetite and cause nausea all at the same time. ^{R1, R12}

Related approved drugs (these are not melanotan II)

Two related peptides went through full development and are approved. Their results do not transfer to melanotan II, and a gray-market "MT2" vial is neither of them. - Afamelanotide (Scenesse): a different alpha-MSH copy (formerly "melanotan I"; see our Melanotan I page), given as an implant under the skin by trained specialists. EU approval Dec 22, 2014 ("exceptional circumstances"); FDA approval Oct 8, 2019. Approved only for adults with erythropoietic protoporphyria (EPP), a rare disease that makes light painful. In the main EU study (93 patients), people on it spent on average 116 pain-free hours in direct sun over 6 months vs 61 on placebo. It is not approved for cosmetic tanning. ^{R21, R22} - Bremelanotide (Vyleesi, "PT-141"): a close chemical relative of melanotan II, often described as its metabolite Caution [UNVERIFIED: no primary source checked for this page]. FDA-approved June 21, 2019 only for low sexual desire in premenopausal women. See our PT-141 page. ^R23

Does it work?

Human Skin darkening: in a pilot phase 1 study (a small first study in people, focused mainly on safety and how the body handles the drug), 3 healthy men got injections on alternating days with saline (salt water) as the comparison. Two had darker skin on the face and upper body. Nausea, sleepiness, tiredness, yawning and stretching, and spontaneous erections lasting 1–5 hours were reported. ^R1

Human Erections: two University of Arizona crossover studies (each man got both drug and placebo, a dummy treatment), 10 men each: - Men with erectile dysfunction with no physical cause: 8 of 10 had erections on melanotan II. Time at strong rigidity averaged 38 minutes vs 3 on placebo. ^R2 - Men with physical risk factors: erections after 12 of 19 injections vs 1 of 21 placebo doses. ^R3 - Nausea and yawning/stretching were more common than on placebo in both. The first also reported less appetite. In the second, 4 of 19 injections caused severe nausea. ^{R2, R3}

The drug was never taken into larger trials. Development moved to bremelanotide instead.

Unknown Skin cancer prevention: no human study has tested this. A tan from melanotan II is not evidence of protection, and darker skin does not mean healthier skin. Sellers' "sun protection" claims are unsupported.

Who paid / conflicts: the human studies were run by the University of Arizona group that invented the compound. Several authors (Hadley, Hruby, Dorr) were its inventors. Caution [UNVERIFIED: funding sources and patent/licensing interests not stated in the abstracts we read] ^R1–R3

Is it safe?

This is the most important section of this page. Melanotan II has never had a proper safety study. Everything below comes from case reports of people who bought it online, and from regulators. A case report shows something happened after use. It can't prove the drug caused it, and it can't tell us how often it happens. Gray-market products may also contain other things (see "What's in the vial?").

What regulators say

• Caution FDA (US): in Aug 2007 FDA sent a warning letter to a US seller for selling melanotan II as an unapproved new drug, saying its tanning and skin-cancer claims were unsupported. The company's owner was later convicted and debarred by FDA (2016). FDA also lists melanotan II on its compounding "significant safety risks" page, noting "published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism." ^{R13, R14, R19}
• Caution UK (MHRA): warned in 2008 that the "tan jab" is an unlicensed medicine that may not be safe. In FOI replies (2021, 2024) MHRA says sale and supply is not permitted, products "may cause serious side effects," and users should stop immediately. ^R15
• Caution Ireland (HPRA): "not safe for use and may cause serious, long-term damage." Lists new and darkening moles, possible loss of vision, muscle tremors, stroke and anaphylaxis (a severe allergic reaction). "Not authorised by the HPRA or any medicines regulator to treat any condition." ^R16
• Caution Denmark (Danish Medicines Agency): warnings in Aug 2008 and Jun 2011: the effect is not documented, there are no studies of side effects, and users should stop. ^R17
• Caution Australia (TGA): prescription-only, not approved for tanning. Its Jan 2025 warning cites increased moles and freckles, kidney problems and brain swelling. TGA lab tests of seized nasal sprays found the amount of melanotan II varied more than twofold between bottles of the same product. ^R18
• EMA (EU): we found no EMA-level safety warning; warnings in Europe come from national regulators. Caution [UNVERIFIED: Norwegian and other national warnings not checked directly]

Case reports (problems reported after use, which may or may not have been caused by the drug)

• Caution Moles changing, new moles, and melanoma: many reports of moles appearing or darkening fast, sometimes within a day of a single injection ^{R4, R5, R6}. Melanoma (the most dangerous skin cancer) has been reported after use, including in a 20-year-old woman who also used sunbeds ^R7 and others ^R8. Most of these people also used sunbeds or sunbathed, so melanotan II's own role can't be separated out. Darker skin can also make changing moles harder to spot.
• Caution Priapism (a painful erection lasting hours, a medical emergency that can cause permanent erectile damage): at least three reports. One man had not recovered erectile function a month later; another needed surgery. ^{R9, R10, R11}
• Caution Muscle breakdown (rhabdomyolysis) and toxic overstimulation: a 39-year-old man who injected six times his intended amount had a racing heart, sweating, tremors and muscle breakdown. ^R24
• Caution Kidney damage: a Swedish case of renal infarction (blocked blood flow killing part of a kidney) "most likely attributed" to melanotan II, with a review of earlier kidney-failure reports. ^R25
• Caution PRES (brain swelling), a condition that can cause headache, seizures and vision loss: reported after melanotan use. ^R26
• Caution Common effects in the small trials: nausea (sometimes severe), yawning and stretching, reduced appetite, tiredness and sleepiness, and spontaneous erections. ^R1–R3

Dropouts vs placebo: the trials were too small and short to report meaningful dropout comparisons. Unknown

What we don't know

• Unknown Long-term safety, including melanoma risk
• Unknown How often any of the harms above happen
• Unknown Whether it protects skin at all
• Unknown Anything about nasal sprays or drops (none of the trials used them)

Is it legal?

• FDA: not approved. FDA considers it an unapproved new drug (warning letter, 2007). ^{R13, R14}
• Compounding: no entry for melanotan II in any category of FDA's 503A nominations list (updated May 14, 2026) or the 503B nominations list (updated Mar 21, 2025). It appears on FDA's "significant safety risks" page (content current Apr 22, 2026). With no list entry and no approved drug, pharmacies have no approved basis to compound it. It sits under that page's "nominated but withdrawn" heading (checked Oct 15, 2026). ^{R19, R20}
• UK, Ireland, Denmark, Australia: sale and supply illegal or prescription-only, as above. ^R15–R18
• Athletes: not named on WADA's 2026 Prohibited List, but S0 bans "any pharmacological substance... with no current approval by any governmental regulatory health authority for human therapeutic use." Melanotan II has no approval anywhere, so S0 applies. Unknown This is our reading, not a WADA ruling. ^R27

What's in the vial?

There is no approved melanotan II product. Every vial, spray or drop is a gray-market product with no quality control. It could contain the wrong compound, the wrong amount, impurities or bacterial toxins, or be fake (counterfeit). Australia's TGA found the amount varying more than twofold across bottles of the same spray; European customs seizures have also turned up melanotan II among falsified injectables. ^{R18, R28} We test retail vials blind under the Open Peptide Standard. See results at /tests/. A passing test covers one batch, tested on one date. It does not mean the compound itself is safe.

What do users report?

Self-report, not evidence.

Unknown TBD. One qualitative study of UK and Ireland online forums (2016–2017; 623 posts from 205 people) looked at why people use it and what side effects they describe (Gilhooley 2021, PMID 34464955; abstract read). We haven't summarized user reports for this peptide yet.

Study details

^R1–R3 Human Human studies

Study	People	Route	Dose used (study arm, not a recommendation)	Follow-up	Reported	Limitations	Citation
Dorr 1996, pilot phase 1 (human)	3 healthy men	Subcutaneous, alternating days with saline	0.01 mg/kg escalated to 0.025–0.03 mg/kg	2 weeks	Skin darkening in 2; nausea; grade II sleepiness/tiredness in 1 at 0.03 mg/kg; spontaneous erections	3 people; single-blind	PMID 8637402
Wessells 1998	10 men, ED without physical cause	Subcutaneous	0.025 mg/kg	Single doses, 6 h monitoring	Erections in 8/10; rigidity time 38 vs 3 min (p=0.0045)	Crossover; tiny	PMID 9679884
Wessells 2000	10 men, ED with physical risk factors	Subcutaneous	0.025 mg/kg	2 doses each arm, 6 h monitoring	Erections after 12/19 vs 1/21 injections; rigidity 45.3 vs 1.9 min (p=0.047); severe nausea after 4/19 injections	Crossover; tiny	PMID 11018622

^{R4–R11, R24–R26} Case reports (selected)

Problem	Report	Citation
Changing moles	Langan 2009, BMJ letter	PMID 19174439
Eruptive moles	Cousen 2009	PMID 19575725
New/darker moles 24 h after one injection	Schulze 2014	PMID 24334249
Melanoma, 20-year-old woman (also sunbeds)	Hjuler 2014	PMID 24355990
Melanoma	Paurobally 2011; Ong 2012 (melanoma in situ)	PMID 21564053; PMID 22724573
Priapism	Devlin 2013; Dreyer 2019; Mallory 2021	PMID 23537392; 30796078; 33460908
Systemic toxicity, rhabdomyolysis	Nelson 2012	PMID 23121206
Renal infarction + review	Peters 2020	PMID 31953620
PRES	Kaski 2013	PMID 23648958

^{R13–R23, R27} Regulatory sources (as of Oct 15, 2026)

• ^R13 FDA warning letter to a US seller of melanotan II, Aug 30, 2007, as described in FDA's notice to the company's owner: https://www.fda.gov/regulatory-information/electronic-reading-room/notice-opportunity-hearing-nooh-manookian-edward-8516 (seller not named here, per our no-vendor policy).
• ^R14 Federal Register, debarment order, Nov 14, 2016: https://www.federalregister.gov/documents/2016/11/14/2016-27244/edward-manookian-also-known-as-ed-manning-debarment-order
• ^R15 MHRA FOI responses 21/1237 (Dec 2021) and 24/274 (2024): https://assets.publishing.service.gov.uk/media/67bc97a898ea2db44fadddb1/FOI_21-1237_.pdf ; https://assets.publishing.service.gov.uk/media/669fbd3aa3c2a28abb50d55a/Final_Redaction_FOI_24_274.pdf . The 2008 MHRA press release ("'Tan jab' is an unlicensed medicine and may not be safe", Nov 17, 2008) is archived at https://webarchive.nationalarchives.gov.uk/ukgwa/20141206031447/http://www.mhra.gov.uk/NewsCentre/Pressreleases/CON031009 . (title and date confirmed in a browser, Oct 15, 2026)
• ^R16 HPRA, "Reminder of serious health risks with ‘Melanotan 2’ self-tan products" (Advisory, Aug 10, 2023), archived copy: https://web.archive.org/web/20230929085343/https://www.hpra.ie/homepage/cosmetics/safety-information/safety-notices/item?t=/reminder-of-serious-health-risks-with-melanotan-2-self-tan-products&id=80a31426-9782-6eee-9b55-ff00008c97d0
• ^R17 Danish Medicines Agency warnings, Aug 11, 2008 and Jun 20, 2011: https://laegemiddelstyrelsen.dk/en/pharmacies/medicines-imported-from-abroad/warnings-against-products/warning-against-the-tanning-product-melanotan/
• ^R18 TGA, "Don't risk using tanning products containing melanotan" (blog, Jan 24, 2025), archived copy: https://web.archive.org/web/20260709125256/https://www.tga.gov.au/news/blog/dont-risk-using-tanning-products-containing-melanotan ; TGA safety alert, "Melanotan II tanning peptide products found to be inconsistently dosed" (Aug 18, 2026): https://www.tga.gov.au/safety/safety-monitoring-and-information/safety-alerts/melanotan-ii-tanning-peptide-products-found-be-inconsistently-dosed ; summarised by Hong Kong's Drug Office (Aug 18, 2026; loads, checked Oct 15, 2026): 5 nasal-spray bottles of one product labelled 30 mg contained an estimated 22 mg to 54 mg: https://www.drugoffice.gov.hk/eps/news/showNews/Melanotan/consumer/2026-08-18/en/57965.html Caution [UNVERIFIED: the TGA alert page returns errors (HTTP 500 / connection failure) and has no Wayback copy as of Oct 15, 2026; its findings and date are confirmed only through the Hong Kong Drug Office summary]
• ^R19 FDA, Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks (content current Apr 22, 2026): https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
• ^R20 FDA 503A nominations list (May 14, 2026): https://www.fda.gov/media/94155/download ; 503B list page: https://www.fda.gov/drugs/human-drug-compounding/503b-bulk-drug-substances-list
• ^R21 EMA, Scenesse EPAR (authorised Dec 22, 2014): https://www.ema.europa.eu/en/medicines/human/EPAR/scenesse
• ^R22 Drugs@FDA (openFDA query, Oct 15, 2026): NDA 210797, SCENESSE, original approval Oct 8, 2019, sponsor Clinuvel. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=210797
• ^R23 Drugs@FDA NDA 210557, Vyleesi, approved Jun 21, 2019: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=210557
• ^R27 WADA 2026 Prohibited List, S0 (official PDF text, saved copy): https://www.wada-ama.org/en/resources/world-anti-doping-code-and-international-standards/prohibited-list

Full reference list (PMIDs verified on PubMed, Oct 15, 2026)

• ^R1 Dorr RT, et al. Life Sci. 1996;58(20):1777-84. doi:10.1016/0024-3205(96)00160-9. PMID 8637402.
• ^R2 Wessells H, et al. J Urol. 1998;160(2):389-93. PMID 9679884.
• ^R3 Wessells H, et al. Urology. 2000;56(4):641-6. doi:10.1016/s0090-4295(00)00680-4. PMID 11018622.
• ^R4 Langan EA, et al. BMJ. 2009;338:b277. doi:10.1136/bmj.b277. PMID 19174439.
• ^R5 Cousen P, et al. Br J Dermatol. 2009;161(3). doi:10.1111/j.1365-2133.2009.09362.x. PMID 19575725.
• ^R6 Schulze F, et al. Eur J Dermatol. 2014;24(1). doi:10.1684/ejd.2013.2227. PMID 24334249.
• ^R7 Hjuler KF, Lorentzen HF. Dermatology. 2014;228(1):34-6. doi:10.1159/000356389. PMID 24355990.
• ^R8 Paurobally D, et al. Br J Dermatol. 2011;164(6):1403-5. doi:10.1111/j.1365-2133.2011.10273.x. PMID 21564053; Ong S, et al. Australas J Dermatol. 2012. doi:10.1111/j.1440-0960.2012.00915.x. PMID 22724573.
• ^R9 Devlin J, et al. Clin Toxicol. 2013;51(4):383. doi:10.3109/15563650.2013.784775. PMID 23537392.
• ^R10 Dreyer BA, et al. BMJ Case Rep. 2019;12(2):e227644. doi:10.1136/bcr-2018-227644. PMID 30796078.
• ^R11 Mallory CW, et al. Sex Med. 2021;9(1):100298. doi:10.1016/j.esxm.2020.100298. PMID 33460908.
• ^R12 Langan EA, et al. Acta Derm Venereol. 2011. doi:10.2340/00015555-1130. PMID 21547334 (review: what "melanotan" means).
• ^R24 Nelson ME, et al. Clin Toxicol. 2012;50(10):1169-73. doi:10.3109/15563650.2012.740637. PMID 23121206.
• ^R25 Peters B, et al. CEN Case Rep. 2020;9(2):159-161. doi:10.1007/s13730-020-00447-z. PMID 31953620.
• ^R26 Kaski D, et al. Ann Intern Med. 2013;158(9):707-8. doi:10.7326/0003-4819-158-9-201305070-00020. PMID 23648958.
• ^R28 Venhuis BJ, et al. Drug Test Anal. 2016;8(3-4):398-401. doi:10.1002/dta.1888. PMID 26456392.

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Disclaimer

This page is for education and harm reduction. It is not medical advice and not a recommendation to use melanotan II. If you have used it, get any new or changing moles checked by a doctor. Seek emergency care for an erection lasting more than 4 hours, severe headache, seizures, vision changes, dark urine or severe muscle pain, and report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch) or your national regulator.