Summary
PT-141 (bremelanotide) is a cyclic melanocortin agonist approved by the FDA in 2019 as Vyleesi, an on-demand injection for low sexual desire in premenopausal women. It works in the brain rather than on blood flow. In two phase 3 trials, it modestly improved desire and reduced distress compared with placebo.
Structure
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH. A cyclic heptapeptide and the carboxylic-acid metabolite of melanotan II.
How it works
Bremelanotide activates melanocortin receptors, mainly MC4R, in the hypothalamus. This is thought to modulate dopamine release in pathways involved in sexual motivation. Unlike PDE5 inhibitors, it does not act primarily on genital blood flow.
Research use cases
Areas where PT-141 has been studied. Inclusion here does not mean it works for that purpose.
- Hypoactive sexual desire disorder in premenopausal women (approved)
- Erectile dysfunction (earlier intranasal studies)
What the research found
RECONNECT phase 3 trials
In two 24-week trials of 1,267 premenopausal women, bremelanotide produced statistically significant but modest improvements in sexual desire scores and reductions in distress compared with placebo. It did not significantly increase the number of satisfying sexual events.1
Safety and open questions
Nausea occurred in about 40% of participants in phase 3, and was the main reason for discontinuation. Flushing, headache, transient blood pressure increases and focal skin darkening (with repeated use) are also reported. The label advises against use in people with uncontrolled hypertension or cardiovascular disease.
Regulatory status
FDA-approved (Vyleesi, 2019) for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Prescription only.
Status was accurate when this page was last reviewed on October 26, 2026. Regulations change; check with the relevant authority before relying on it.
PT-141: common questions
Is PT-141 the same as melanotan II?
They are closely related. Bremelanotide is the metabolite of melanotan II with a free carboxylic acid instead of an amide. It was developed for sexual function and has less tanning effect, though repeated use can still darken skin.
Is PT-141 approved for human use?
FDA-approved (Vyleesi, 2019) for acquired, generalized hypoactive sexual desire disorder in premenopausal women. Prescription only.
References
- Kingsberg SA, Clayton AH, Portman D, et al. (2019). Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstetrics & Gynecology.
Links open a PubMed search for the exact title, or the original source where one is given.