PT-141 : données probantes, mécanisme et limites

PT-141 is another name for bremelanotide, a synthetic analog of alpha-melanocyte-stimulating hormone. In the United States it is sold as VYLEESI, a prescription medicine. Its approved use is narrow: premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), meaning low desire that causes marked distress or interpersonal difficulty and is not due to another medical or psychiatric condition, relationship problems, or a medicine or drug.

The VYLEESI label describes bremelanotide as a nonselective melanocortin receptor agonist. At the levels used, binding to MC1R and MC4R is the most relevant. MC4R is found in many brain areas linked to desire and arousal, and MC1R on pigment cells explains the skin darkening. The label states that the mechanism by which it improves HSDD in women is unknown. Unlike PDE5 inhibitors such as sildenafil, it is not thought to act mainly through direct effects on blood vessels.

Human trials: two identical Phase 3, randomized, double-blind, placebo-controlled trials, called RECONNECT, enrolled more than a thousand premenopausal women with HSDD for 24 weeks. Of 1,267 women randomized, those given bremelanotide had modest but statistically significant increases in sexual desire and reductions in related distress compared with placebo. A 52-week open-label extension without a control group, which 684 women entered and 272 completed, reported no new safety signals. The trials were funded by the developers, Palatin Technologies and AMAG Pharmaceuticals.

Human studies in men: early studies, one led by researchers at the developer, tested PT-141 in healthy men and in men with erectile dysfunction, including a placebo-controlled crossover study in men with an inadequate response to Viagra. They reported statistically significant erectile responses measured by RigiScan. These were early-phase studies, few controlled trials have tested it in men, and use in men is outside the label.

The VYLEESI label lists nausea, flushing, reactions where the drug is given, headache and vomiting as the most common adverse reactions. Its warnings cover a temporary rise in blood pressure and fall in heart rate after each use, focal hyperpigmentation (darkening of skin, including the face, gums and breasts), which was more likely in people with darker skin and with more frequent use and whose resolution was not confirmed in all patients, and nausea that sometimes needed treatment or led people to stop. It is contraindicated in uncontrolled high blood pressure or known cardiovascular disease. The label carries no boxed warning.

Products sold online as PT-141 are not the approved medicine, and their identity and purity are not verified by a regulator.

Bremelanotide is FDA-approved only as VYLEESI for HSDD in premenopausal women. Health Canada's Drug Product Database lists no bremelanotide product, so it is not authorized in Canada. Use in men is off-label. It is not named on the 2026 WADA Prohibited List, and the List's section S0 applies only to substances with no current approval by any government health regulator for human therapeutic use.