The only FDA-approved peptide for sexual dysfunction that works through the central nervous system rather than the vascular system. PT-141 activates melanocortin-4 receptors in the brain to enhance sexual arousal and desire—a fundamentally different mechanism than PDE5 inhibitors like sildenafil, which only address blood flow.
In Phase III trials, PT-141 increased the number of satisfying sexual events by 0.7 per month and significantly improved sexual desire scores on the FSFI scale.
Kingsberg et al., Obstetrics & Gynecology, 2019
| Molecular Formula | C50H68N14O10 |
| Structure | 7-amino acid cyclic peptide |
| Half-Life | ~2.7 hours |
| Administration | Subcutaneous injection |
| Legal Status | FDA Approved |
| Power Rating | 5/5 |
PT-141 (Bremelanotide) is a synthetic cyclic heptapeptide melanocortin receptor agonist that primarily activates MC4R in the hypothalamus. Unlike PDE5 inhibitors (Viagra, Cialis) which act on peripheral vascular smooth muscle, PT-141 acts centrally on the nervous system to enhance sexual desire, arousal, and motivation. It was originally developed from Melanotan II but refined to isolate the sexual function effects.
PT-141 is FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD). It has completed multiple Phase III clinical trials demonstrating statistically significant improvements in sexual desire and satisfying sexual events. The drug represents a first-in-class mechanism for sexual dysfunction treatment, acting through central melanocortin pathways rather than peripheral vasodilation. Research in male sexual dysfunction has shown improvements in erectile function, including in men who did not respond to PDE5 inhibitors.
Common side effects include nausea (reported in ~40% of subjects, typically mild and decreasing with use), flushing, headache, and injection site reactions. Transient increases in blood pressure have been observed. PT-141 carries an FDA black box warning limiting use to no more than 8 doses per month. The nausea effect typically diminishes significantly after the first few administrations.
PT-141 is FDA-approved as Vyleesi (bremelanotide) and available by prescription. It is also available as a research chemical from peptide vendors. The FDA-approved form is a pre-filled auto-injector; research forms are lyophilized powder.
All vendors listed sell products labeled strictly for research purposes only.