# PT-141 (Bremelanotide): The Recent-Research Ledger > PT-141 (bremelanotide) is a melanocortin-receptor agonist approved in 2019 for HSDD in premenopausal women. A ruled, cited ledger of what the recent trials measured and what remains off-label. A balanced, cited account of bremelanotide: the two Phase 3 trials in 1,267 women, the 2019 FDA approval, the half-life on the label, and the honest qualifications kept in their own ruled lines. ## The short version PT-141 (the lab name for the drug **bremelanotide**) is a small synthetic peptide that acts on the brain to influence sexual desire. It copies a natural signaling molecule called alpha-MSH (a hormone the body makes), and it switches on receptors called **melanocortin receptors** (cell switches in the brain that, among other jobs, help regulate sexual motivation and appetite). It does **not** work on blood flow the way the older erectile-dysfunction pills do — it works in the brain's wiring, not in the plumbing. In 2019 the FDA approved PT-141, under the name bremelanotide, for one specific use: low sexual desire that causes distress in women who have not yet reached menopause [7]. The trials behind that approval found a real but modest improvement [3]. The most common downside was nausea [4]. Every other use you may read about — men, postmenopausal women, or "performance" — is **off-label or research-grade**, not an approved use [7]. What people report, including the downsides, is on [PT-141 effects](/effects). ## What is PT-141 PT-141 is a synthetic **cyclic heptapeptide** (a ring-shaped chain of seven amino acids) and the research-community name for the drug **bremelanotide** [1]. Its molecular weight is 1025.2 Da and its formula is C50H68N14O10; it carries the CAS number 189691-06-3 and was approved under NDA 210557 [7]. It is a structural relative of an older melanocortin compound, redesigned with a stabilizing ring so it survives longer in the body [1]. The compound is an **agonist** (an activator) at the melanocortin-3 and melanocortin-4 receptors — MC3R and MC4R — which sit mostly in the central nervous system [1]. That central location is the whole story: it is why PT-141 influences desire through brain circuits rather than through the vascular smooth muscle that erectile-dysfunction tablets target [1]. The most authoritative figures on this page come from the 2019 US prescribing information and the peer-reviewed trial record, both cited on [PT-141 references](/references). ## What the recent trials measured The two pivotal Phase 3 trials, run as a matched pair under the program name RECONNECT, enrolled 1,267 premenopausal women with hypoactive sexual desire disorder (HSDD) [3]. Bremelanotide 1.75 mg, given subcutaneously as needed, improved sexual desire on the FSFI-desire scale by an integrated +0.35 (P<.001) and reduced desire-related distress on the FSDS-DAO scale by an integrated −0.33 (P<.001) over 24 weeks, against placebo [3]. Both coprimary endpoints were met in both trials [3]. A 52-week open-label extension in 684 women found the improvement was sustained, with no new safety signals; the most common drug-related effects were nausea (40.4%), flushing (20.6%), and headache (12.0%) [4]. A 2022 mechanistic fMRI study in 31 women added the picture from inside the brain: MC4R activation raised reported desire for up to 24 hours and changed how the brain processed erotic stimuli, including stronger amygdala–insula connectivity [5]. The full quantified record lives on [PT-141 results](/results). ## The honest qualifications A balanced ledger carries its debits in plain sight. Independent re-analyses (Spielmans 2021, 2024) argue the measured effects on desire and distress, while statistically significant, are small, and they question how clinically meaningful the outcomes are [11][12]. Nausea is the principal tolerability issue and a real driver of discontinuation [4]. The label warns of transient blood-pressure increases and contraindicates use in uncontrolled hypertension or known cardiovascular disease [7]. The scope of approval matters most. PT-141 is approved **only** for premenopausal women with HSDD — not for men, not for postmenopausal women, and not to enhance performance [7][9]. A 2024 program to test bremelanotide alongside a PDE-5 inhibitor for male erectile dysfunction is **investigational** Phase 2, not an approval [8]. And material sold as a "PT-141 research chemical" sits entirely outside the pharmaceutical framework, with no oversight of identity, purity, or concentration [7]. ## How to read this site This is an editorial digest, organized as a ledger. The measured human-data findings — the trial figures, the label pharmacokinetics — read as cited entries in the credit column. The qualifications — the small-effect critique, the nausea rate, the blood-pressure warning, the premenopausal-only boundary — read as clearly marked entries in the debit column. Nothing here is a recommendation, and no dose on this page is advice for any individual. The [PT-141 research](/research) page covers mechanism and the key studies. [PT-141 results](/results) collects the quantified outcomes. The dosage page sets out the label's pharmacokinetics in research context. [Is PT-141 fda-approved](/fda-approval) walks the regulatory status in detail, and [PT-141 effects](/effects) covers reported benefits, side effects, and cited safety cautions. --- An azure-ruled ledger of the PT-141 (bremelanotide) record — the 2019 approval, the 1,267-woman trials, and the half-life on the label entered as cited credits, with the small-effect critique, the ~40% nausea, and the premenopausal-HSDD-only boundary ruled in plain sight as the debits they are; no clinic balances behind this page and nothing here is dosed, prescribed, or sold.