The melanocortin peptide that works on the brain rather than the bloodstream — FDA approved as Vyleesi for female sexual arousal, and widely used off-label for male libido.
PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide analog of alpha-MSH (α-melanocyte-stimulating hormone). It is a non-selective melanocortin-receptor agonist with bias toward MC3R/MC4R but also activity at MC1R (the basis of its hyperpigmentation side effect) and MC5R. Unlike erectile dysfunction drugs that act on peripheral blood flow, PT-141 works in the central nervous system — it increases sexual desire and arousal.
It is FDA approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. Off-label use for male libido and erectile dysfunction is widespread and generally well tolerated.
FDA approved (Vyleesi) for premenopausal HSDD. Not WADA prohibited. Available as research chemical for off-label use.
Activates MC4R in the hypothalamus, triggering downstream dopamine release in sexually-relevant brain circuits — drives desire and arousal at a central level, not peripheral.
Because PT-141 acts on desire rather than blood flow, it can work for people who don’t respond to Viagra/Cialis — or who have psychogenic issues that require a libido boost rather than vascular support.
Onset typically 30–60 minutes post-injection, duration 4–6 hours. Effects can persist subtly for 12+ hours in some users.
| Benefit | Evidence |
|---|---|
| Female libido (HSDD) | RECONNECT trials: statistically significant improvement in desire and arousal over placebo |
| Male erectile function | Phase 2 trials (Diamond et al.): 33% of non-responders to PDE-5s achieved satisfactory erections |
| Complement to PDE-5s | Combines effectively with sildenafil/tadalafil when needed (clinician supervision recommended) |
| Postmenopausal benefits | Anecdotal and off-label data suggest improvements beyond the FDA-approved premenopausal population |
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Start Tracking FreeImportant: FDA approval and Phase 3 efficacy evidence for bremelanotide are limited to premenopausal women with HSDD (PMIDs 31893927, 31599847, 33455598, 35147466). Male dosing is off-label and lacks the same evidence base — treat the 1–2 mg male range as community convention, not trial-validated.
10 mg vial + 2 mL BAC water = 5 mg/mL
| Dose | Volume | Syringe Units |
|---|---|---|
| 0.5 mg | 0.10 mL | 10 units |
| 1 mg | 0.20 mL | 20 units |
| 1.75 mg | 0.35 mL | 35 units |
| 2 mg | 0.40 mL | 40 units |
10 mg vial at 1.75 mg/use = ~5 doses per vial
Pre-filled with a typical PT-141 (Bremelanotide) setup. Edit any field — the draw updates live.
Insulin syringe — 100 units = 1 mL
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Phase 3 meta-analysis (PMID 33678061) showed bremelanotide-treated subjects had substantially higher adverse-event-driven discontinuation than placebo (OR ~12, NNH ~6) — roughly 1 in 6 users may stop due to side effects. Long-term open-label data (PMID 31599847) echoes the tolerability burden. This is why the starter-dose approach matters: confirm you can tolerate a smaller dose before escalating.
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Start Tracking FreeYes — for one specific indication. PT-141 (bremelanotide) is FDA approved under the brand name Vyleesi (approved June 2019) for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. The approved product is a 1.75 mg single-use prefilled subcutaneous autoinjector. Use in men, postmenopausal women, or for general libido enhancement is off-label.
FDA-approved Vyleesi dose: 1.75 mg subcutaneously, taken at least 45 minutes before anticipated sexual activity, no more than once per 24 hours and no more than 8 times per month. Off-label community dosing in men typically uses 1–2 mg subcutaneously as needed — treat the 1–2 mg male number as community convention, NOT as a trial-validated dose. No adequately powered male efficacy trial has been published.
A typical reconstitution is 10 mg of bremelanotide + 2 mL of bacteriostatic water, yielding 5 mg/mL. A 1.75 mg dose draws to 0.35 mL (35 units on a 100-unit insulin syringe), 2 mg = 0.40 mL (40 units). Note: the FDA-approved Vyleesi product is a prefilled autoinjector, not vials — these reconstitution instructions apply only to research-grade lyophilized bremelanotide.
Vyleesi label specifies dosing at least 45 minutes before anticipated activity. Peak plasma concentration occurs at ~1 hour post-SC injection. Plasma half-life is approximately 2.7 hours (range 1.9–4.0 h), so the drug is essentially gone by ~13 hours. Subjective effects sometimes reported beyond that window are anecdotal and not characterized in trials — claims of "24+ hour duration" exceed the pharmacokinetic data.
Per the Vyleesi label, the most common adverse reactions (≥4% of patients) are nausea (40% — often pronounced; sometimes requires antiemetic), flushing, injection site reactions, headache, and vomiting. Less common: transient blood-pressure increase (the label includes a warning), focal hyperpigmentation (particularly with repeated dosing — face, breasts, gums), and nasal congestion. The melanocortin mechanism that drives the desired effect is the same mechanism behind the pigmentation side effect.
It is off-label, but yes. The 2024 Goldstein observational study (cited in some sources, observational and lacks placebo control) reportedly showed improvements in desire, erection quality, and satisfaction. There is no adequately powered male efficacy RCT. Community use is widespread; the evidence base is not. Marketing/anecdotal claims ("works for everyone," "stronger orgasms," "better than Viagra") exceed the trial-validated evidence.
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