PT-141 vs Melanotan II: Which Is Right for You?
PT-141 (bremelanotide) is FDA-approved as Vyleesi for low sexual desire (HSDD) in premenopausal women. Melanotan II is an unapproved, related melanocortin peptide sold as a tanning agent; regulators have warned against it.
Side-by-side comparison
| PT-141 | Melanotan II | |
|---|---|---|
| Class | Melanocortin receptor agonist | Melanocortin receptor agonist (non-selective) |
| FDA status | Approved (Vyleesi, 2019) | Not approved |
| Approved use | HSDD in premenopausal women | None |
| How used (label) | 1.75 mg autoinjector, as needed | — |
| Common effects | Nausea, flushing, headache | Nausea, flushing, darkened skin and moles |
Complete comparison (2026)
Key takeaways
- Bremelanotide was developed from melanotan II.
- Only PT-141 has an FDA-approved product.
- Melanotan II has been linked in case reports to changes in moles.
What are PT-141 and Melanotan II?
PT-141 (bremelanotide) is a melanocortin-receptor agonist, FDA-approved as Vyleesi for hypoactive sexual desire disorder in premenopausal women.
Melanotan II is a synthetic melanocortin-receptor agonist that darkens skin; it is unapproved and regulators have warned against its use.
Mechanism differences
Both activate melanocortin receptors. Bremelanotide acts mainly at MC4R in the brain; melanotan II also strongly activates MC1R in skin pigment cells, which causes tanning.
Effectiveness
In the RECONNECT phase 3 trials, bremelanotide improved desire scores and reduced distress compared with placebo in premenopausal women with HSDD. Melanotan II has no approved indication and no completed phase 3 program.
Side effect profiles
Vyleesi's label lists nausea (about 40% in trials), flushing and headache, transient blood-pressure increases, and focal hyperpigmentation. Melanotan II case reports describe new or changing moles, and regulators including FDA have warned consumers about unapproved tanning injections.
Dosing & administration
Vyleesi label: 1.75 mg under the skin at least 45 minutes before anticipated sexual activity; no more than one dose in 24 hours or eight per month. Melanotan II has no label.
Cost
Vyleesi is a prescription brand. Melanotan II is sold as a "research" product; see its page for listings.
FDA & regulatory status
PT-141: FDA-approved as Vyleesi. Melanotan II: not approved.
Who should choose which
Vyleesi is a prescription decision for a specific diagnosis. Melanotan II has no legitimate use case.
What the evidence does not show
- Safety of melanotan II in any controlled trial.
- Benefit of PT-141 outside its labeled population.
Frequently asked questions
Are PT-141 and melanotan II the same?
No. Bremelanotide (PT-141) was developed from melanotan II but has a different receptor profile and an FDA-approved product.
Is melanotan II legal?
It is not approved for any use. Products sold as research chemicals are not for human use.
Who is Vyleesi approved for?
Premenopausal women with acquired, generalized hypoactive sexual desire disorder.
References
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