PT-141 and Melanotan II both act on the melanocortin system, and Melanotan II is even where PT-141 originated — but they've ended up worlds apart. PT-141 (bremelanotide) is an FDA-approved drug for low sexual desire; Melanotan II is an unapproved tanning chemical with notable safety concerns.
At a glance
| PT-141 | Melanotan II | |
|---|---|---|
| Class | Melanocortin agonist (bremelanotide) | Non-selective melanocortin agonist |
| Brand name | Vyleesi | None (research chemical) |
| FDA status | Approved | Not approved |
| Primary use | Low sexual desire (HSDD) in premenopausal women | Sold online for tanning / libido |
| Mechanism focus | Central pathways for sexual desire | Broad melanocortin (incl. pigmentation) |
| Safety oversight | Prescribed and monitored | Unregulated; concerns incl. mole changes, nausea |
The bottom line
Bottom line: PT-141 is the refined, approved descendant — a prescription drug for sexual desire that acts centrally. Melanotan II is the older, unapproved compound sold for tanning, with documented safety concerns including nausea and changes to moles. They share a receptor family but not a safety or regulatory profile.
Frequently asked questions
Are PT-141 and Melanotan II the same?
They are related melanocortin peptides — PT-141 (bremelanotide) was derived from Melanotan II — but they are different compounds. PT-141 is FDA-approved (Vyleesi) for low sexual desire; Melanotan II is an unapproved tanning chemical.
Which one is approved?
PT-141 (bremelanotide, brand Vyleesi) is FDA-approved for hypoactive sexual desire disorder in premenopausal women. Melanotan II has no approval and is sold as a research chemical.
Is Melanotan II safe?
Melanotan II is unapproved and unregulated. Reported concerns include nausea, flushing, and changes to moles that can complicate melanoma detection, and product purity is not guaranteed.
References
Combined peer-reviewed sources from both peptide guides. Inclusion is not endorsement.
- Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials (RECONNECT). Obstet Gynecol. 2019. Peer-reviewed study
- Molinoff PB, Shadiack AM, Earle D, Diamond LE, Quon CY. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Ann N Y Acad Sci. 2003. Peer-reviewed study
- Hedlund P. PT-141 Palatin. Curr Opin Investig Drugs. 2004. Peer-reviewed study
- Dhillon S, Keam SJ. Bremelanotide: First Approval. Drugs. 2019. Peer-reviewed study
- Diamond LE, Earle DC, Garcia WD, et al. Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response. Urology. 2005. Peer-reviewed study
- Rosen RC, Diamond LE, Earle DC, et al. Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra. Int J Impot Res. 2004. Peer-reviewed study
- Hjuler KF, Lorentzen HF. Melanoma associated with the use of melanotan-II. Dermatology. 2014. Peer-reviewed study
- Cousen P, Colver G, Helbling I. Eruptive melanocytic naevi following melanotan injection. Br J Dermatol. 2009. Peer-reviewed study
- 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. Peer-reviewed study
- Wekwejt P, Wojda U, Kiryk A. Melanotan-II reverses memory impairment induced by a short-term HF diet. Biomed Pharmacother. 2023. Peer-reviewed study
- Gilhooley E, Daly S, McKenna D. Melanotan II User Experience: A Qualitative Study of Online Discussion Forums. Dermatology. 2021. Peer-reviewed study
- Tomassi S, Dimmito MP, Cai M, et al. CLIPSing Melanotan-II to Discover Multiple Functionally Selective hMCR Agonists. J Med Chem. 2022. Peer-reviewed study