What Is PT-141?
PT-141 (bremelanotide) is a synthetic cyclic peptide melanocortin-receptor agonist, FDA-approved in 2019 under the brand name Vyleesi as an on-demand treatment for acquired, generalised hypoactive sexual desire disorder (HSDD) in premenopausal women. It is a metabolite of the tanning peptide melanotan II and acts centrally on melanocortin pathways involved in sexual arousal rather than on the vascular mechanism of PDE5 inhibitors like sildenafil. It is a genuine, regulator-reviewed drug for its approved indication; its off-label use in men and for general “libido enhancement” is not the approved use and is far less well characterised.
Evidence
Approval rested on the RECONNECT programme: two identically designed phase 3, randomised, double-blind, placebo-controlled trials in premenopausal women with HSDD, in which subcutaneous bremelanotide 1.75 mg as needed produced statistically significant improvements in sexual desire and reductions in related distress versus placebo 1Reference 1RCTBremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials — randomised/RCTView study →. The effect sizes were modest and nausea was common. Evidence for the popular off-label uses — men’s libido, general arousal enhancement — is much thinner than the female-HSDD data, and I did not find comparably robust trials for those uses in this quick pass.
Dosage & Safety
The approved regimen is 1.75 mg subcutaneously as needed, at least 45 minutes before anticipated activity, with a labelled maximum of one dose per 24 hours and eight per month — this is the drug’s prescribing information, not a personal recommendation. Common adverse effects include nausea, flushing, headache and injection-site reactions; bremelanotide transiently raises blood pressure and lowers heart rate, so it is contraindicated in uncontrolled hypertension or known cardiovascular disease, and can cause focal hyperpigmentation with repeated use 1Reference 1RCTBremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials — randomised/RCTView study →. It is an FDA-approved prescription drug, not a dietary supplement; grey-market “research peptide” versions are unregulated and of unverified purity. Informational only — this is not medical advice.
References
- Kingsberg SA et al. (2019). Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials — randomised/RCT. Obstet Gynecol. https://pubmed.ncbi.nlm.nih.gov/31599840/