What it is
A synthetic cyclic heptapeptide analog of alpha-MSH, developed as a metabolite of melanotan II. Supplied as a prefilled autoinjector (Vyleesi).
How it works
Acts as a non-selective melanocortin receptor agonist with preferential activity at MC4R, which is implicated in central regulation of sexual response.
Where it's used
Used in premenopausal women for acquired, generalized hypoactive sexual desire disorder (HSDD).
FDA-approved use
Treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD).
Tracking it
PT-141 is injectable, so two things matter in a log: when you dosed and where. Rotating sites and writing both down prevents the classic “did I already pin the left side?” problem. with a half-life of about 2.7 hours, a dose log also lets a tracker model the relative amount still in your system between doses.
Source
OpenFDA
Last reviewed 2026-06-11