# PT-141 (Bremelanotide): Approved Use, Off-Label Use, and the Evidence > PT-141 (bremelanotide) is FDA-approved for premenopausal HSDD in women only. Everything else is off-label or research-grade. A measured clinical reading of the record, cited. A measured clinical reading of the bremelanotide record: the one indication the FDA cleared, the studies behind it, and the line between label-attested fact and study-attested finding. ## The short version PT-141 is the lab name for bremelanotide, a small synthetic peptide that acts on the brain rather than the blood vessels. It switches on a set of brain receptors (called melanocortin receptors, the same family the body's own "alpha-MSH" hormone uses) that help drive sexual desire. That central-brain route is what makes it different from the more familiar erection pills, which work on blood flow in the body. Here is the one fact that organizes everything else: in 2019 the FDA approved bremelanotide for a single, narrow use — low sexual desire that causes distress (called HSDD) in women who have not yet reached menopause [7]. That approval does not cover men, postmenopausal women, or "performance." Those uses have been studied to varying degrees but are off-label or research-grade, and we label them that way throughout this site. What to watch for is real: nausea is common, blood pressure can rise briefly, and repeated dosing can darken the skin [3][4][7]. The honest benefits, the reported effects, and the downsides are laid out on [PT-141 effects](/effects). ## What is PT-141 PT-141 is a synthetic cyclic heptapeptide — a ring of seven amino acids — that acts as an agonist (a switch that turns a receptor on) at melanocortin receptors, chiefly MC4R and MC3R [1]. These receptors sit mostly in the central nervous system, in hypothalamic circuits tied to sexual motivation. Its international nonproprietary name is bremelanotide; the two names refer to the same molecule [7]. Mechanistically it is a relative of the tanning peptide melanotan-II, re-engineered so the C-terminal end carries a carboxylic acid instead of an amide [12]. That small change shifts the molecule toward the sexual-desire pathway. When given systemically, it produced penile erections in rats and nonhuman primates and activated hypothalamic neurons (measured as increased c-Fos), and it produced rapid, dose-dependent erectile activity in men with erectile dysfunction in early trials [1]. The central, brain-first mechanism is the throughline of the whole literature. ## What is PT-141 peptide, in one paragraph The PT-141 peptide is bremelanotide: sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, molecular weight about 1025 Da, CAS 189691-06-3 [7]. The "cyclo" part means a lactam bridge closes the ring between two side chains, which makes it more stable than a straight-chain peptide. It is not made by the body; it is a synthetic analogue of alpha-MSH, a natural melanocortin hormone cleaved from a precursor protein called POMC [1]. As a pharmaceutical it is dosed by subcutaneous injection; the early intranasal form was dropped during development for inconsistent absorption [10]. ## Why this site leads with approval status Most of what circulates about PT-141 blurs a line that actually matters: the difference between an approved drug and a research-grade peptide sold under the same lab name. Bremelanotide cleared two pivotal Phase 3 trials (the RECONNECT program, 1,267 premenopausal women with HSDD) and a 52-week open-label extension before approval [3][4]. That is real human evidence — for that one population, at one dose, by one route. The "PT-141" sold as a research chemical sits outside that framework entirely: no regulatory oversight of identity, purity, or concentration. This site reads the published record straight and keeps approved use, off-label use, and research-grade material clearly separated. Start with [is PT-141 fda-approved](/fda-approval), or read the evidence summary at [PT-141 reviews](/reviews). ## How the record is organized here The mechanism and the key trials are summarized on [PT-141 research](/research). The label-attested approved dose and the studied dose ranges — research context only, no recommendation — are on the dosage page. The benefits, the reported effects, and the cited safety cautions are on [PT-141 effects](/effects). Every quantitative claim on the site maps to a numbered source on [PT-141 references](/references). Nothing here is medical advice, and no dose is recommended for any individual. --- A clinical reading room for the PT-141 (bremelanotide) record, read under one desk lamp — the single approved use logged in crimson before anything else, the label figures kept apart from the study findings and both apart from the unverified reports, with no clinic behind the door and nothing here dosed, sourced, or sold.