This page describes published research and public regulatory records. It is not medical advice. SoluneFit does not sell, supply, or recommend any compound. The SoluneFit app includes a private, on-device tracker for people who want a record of what they and their clinician have already decided — the app neither suggests compounds nor doses.
Also known as: PT-141, PT141, Vyleesi, bremelanotide acetate.
Regulatory status
FDA-approved 2019 as Vyleesi 1.75 mg autoinjector for acquired, generalised HSDD in premenopausal women; prescription only [1].
What it is
Melanocortin receptor agonist (cyclic heptapeptide derived from melanotan II).
An on-demand injected peptide approved in the US (Vyleesi, 2019) for premenopausal women with acquired, generalised hypoactive sexual desire disorder. It is not approved for men, postmenopausal women or to enhance sexual performance.
What the published research shows
Two identical phase 3 RECONNECT RCTs, 1,267 women randomised, 24 weeks; modest improvement in desire and distress versus placebo.
Published human studies and reports (these describe trial populations, not SoluneFit claims):
- Hypoactive sexual desire disorder, premenopausal women (Vyleesi label): 1.75 mg SC in the abdomen or thigh at least 45 minutes before anticipated sexual activity; no more than 1 dose in 24 hours and no more than 8 doses per month; label says to stop after 8 weeks if no improvement.
- RECONNECT phase 3 trials (Kingsberg et al. 2019): Two double-blind placebo-controlled trials, 1,267 women randomised (1,202 in efficacy population), 1.75 mg as needed for 24 weeks; significant improvement in desire and in distress versus placebo.
Mechanism, as reported
Activates melanocortin receptors, mainly MC4R in the brain; how this improves sexual desire is not fully known.
Practical record
- Elimination half-life: 2.7 h (confidence: high). Label: terminal half-life about 2.7 h (range 1.9-4.0) after 1.75 mg SC; median Tmax about 1 h; bioavailability about 100 %; Vd 25.0 ± 5.8 L; protein binding 21 %.
- Studied routes: subcutaneous.
- Typical supply: Rx: single-dose 1.75 mg / 0.3 mL autoinjectors (Vyleesi). Also sold unregulated as 'PT-141' lyophilised vials.
- Reconstitution: Label product is a ready solution; not reconstituted.
- Storage: Label: at or below 25 °C, protect from light, do not freeze.
Safety signals on record
- Reported adverse events: Label (vs placebo): nausea 40.0 % vs 1.3 %, flushing 20.3 % vs 0.3 %, injection-site reactions 13.2 % vs 8.4 %, headache 11.3 % vs 1.9 %, vomiting 4.8 % vs 0.2 %. Focal skin darkening (face, gums, breasts) in about 1 % in trials and 38 % with 8 consecutive daily doses; more likely with darker skin.
- Contraindications: Uncontrolled high blood pressure or known cardiovascular disease.
- Interactions: Slows gastric emptying, which may reduce absorption of oral drugs; can markedly lower oral naltrexone levels.
- Notes: Each dose briefly raises blood pressure (about 6/3 mmHg, peaking 2-4 h, back to baseline by about 12 h) and lowers heart rate slightly. Unregulated 'PT-141' products are not the labelled product.
Sources
- VYLEESI (bremelanotide injection) — US Prescribing Information (DailyMed) (2025)
- Kingsberg SA et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol 2019;134(5):899-908 (2019)
General wellness education, not medical advice. Unapproved compounds have no established dosing, purity standard, or safety profile.