PT-141
MetabolicAlso known as: Bremelanotide, Vyleesi, Melanocortin receptor agonist
PT-141 (Bremelanotide/Vyleesi) is FDA-approved for HSDD in premenopausal women. Use outside this indication is off-label. Research vials are not pharmaceutical grade. For informational purposes only.
Overview
PT-141 (Bremelanotide) is a synthetic melanocortin receptor agonist FDA-approved for hypoactive sexual desire disorder (HSDD) in premenopausal women. It acts centrally on the nervous system rather than peripherally, distinguishing it mechanistically from PDE5 inhibitors like sildenafil.
Research Summary
PT-141 activates MC3R and MC4R receptors in the hypothalamus, triggering downstream sexual arousal pathways independent of vascular effects. Phase 3 trials supporting Vyleesi approval showed statistically significant improvements in desire and reductions in distress in women with HSDD. Off-label research explores use in men with erectile dysfunction refractory to PDE5 inhibitors.
Dosing Range
low
0.5mg
moderate
1.75mg
high
2mg
Units: mg · Frequency: as needed, 45 minutes before activity (max 1x per 24h)
Dosing ranges are aggregated from preclinical research and community protocols. Not medical dosing guidance.
Administration Routes
Reconstitution Notes
Reconstitute with bacteriostatic water. Stable 28 days refrigerated. The FDA-approved Vyleesi autoinjector contains 1.75mg per dose.Step-by-step reconstitution guide →
Reported Side Effects
- Nausea (most common — ~40% in trials)
- Flushing
- Headache
- Transient blood pressure elevation
- Hyperpigmentation with chronic use
- Fatigue
Research Papers
Community Experiences
Aggregated from public forums. Anecdotal — not clinical evidence.
Community experience logs on PT-141 dosing, timing, and side effect management.
View original threadOverview
PT-141 emerged from research on Melanotan II — a melanocortin agonist studied for tanning. During trials, researchers noted unexpected sexual arousal as a side effect, leading to targeted development of PT-141.
Central Mechanism
Unlike sildenafil or tadalafil (which act on blood vessels), PT-141 acts centrally — on melanocortin receptors in the brain. This means it can work independently of vascular health, making it potentially useful in cases where PDE5 inhibitors fail.
Approval Context
Vyleesi was FDA-approved in 2019 for HSDD in premenopausal women — the second drug ever approved for this indication (after flibanserin/Addyi). The approval was based on two Phase 3 RCTs showing modest but statistically significant improvements in desire scores and reduced distress.
Research Notes
Hyperpigmentation is a concern with repeated use — PT-141 activates MC1R in skin melanocytes. This is generally reversible but has been noted in long-term users.
Want to calculate your dose? Use the dosing calculator →