PT-141
Also known as · Bremelanotide · Vyleesi · Melanocortin-4 agonist
- EvidenceApproved
- CategoryMelanocortin
- RoutesubQ
- Half-life~2.7 h (range 1.9–4.0 h)
01 / Dosing schedule
Cited dosing
The FDA-approved dose is 1.75 mg subcutaneously, as-needed, at least 45 minutes before anticipated sexual activity. No more than one dose per 24 hours and no more than 8 doses per month.
Vyleesi — on-demand subcutaneous
| Phase | Dose & frequency |
|---|---|
| Standard dose | 1.75 mg subQ as-needed |
| Timing | At least 45 minutes before anticipated sexual activity |
| Frequency cap | No more than one dose in 24 hours |
| Monthly cap | Do not exceed 8 doses per month |
| Discontinuation | Discontinue after 8 weeks if no symptom improvement (per label) |
Source · FDA label — Vyleesi (2019) ↗
Source indication · Hypoactive sexual desire disorder in premenopausal women (Vyleesi label).
- Injection frequency
- As-needed, minimum 45 min pre-activity, maximum 1 dose per 24 h.
- Injection sites
- Abdomen or thigh.
02 / Reconstitution
Reconstitution reference
Research-grade PT-141 typically ships as a 10 mg lyophilized vial. A common prep is 10 mg with 2 mL bacteriostatic water = 5 mg/mL (5000 mcg/mL). At that concentration, a 1.75 mg dose is 0.35 mL = 35 units on a U‑100 syringe.
03 / Overview
Protocol overview
PT-141 (bremelanotide) is a synthetic melanocortin-receptor agonist. It acts centrally on MC4 receptors rather than peripherally on the vascular system.
The FDA-approved indication is hypoactive sexual desire disorder (HSDD) in premenopausal women. Male efficacy data exists in earlier trials but was not the pivotal-trial population.
Onset is roughly 45 minutes and the effect window is not fully characterized, so the label positions it as event-triggered rather than daily.
Nausea is the most frequently reported adverse effect; the label notes it typically occurs within the first hour and resolves within 2 hours.
04 / References