PT-141

Status FDA-approved (Vyleesi) for hypoactive sexual desire disorder in premenopausal women; not approved for use in menBest evidence E1Sources checked 2026-09-18

PT-141 (bremelanotide) is FDA-approved as Vyleesi, an on-demand 1.75 mg subcutaneous injection for hypoactive sexual desire disorder in premenopausal women. It has no approval and no published Phase 3 trial for use in men, despite circulating that way.

What it is

PT-141 is the research-chemical name for bremelanotide, a synthetic cyclic heptapeptide melanocortin receptor agonist (MC1R and MC4R). It was developed from Melanotan II by removing the C-terminal amide, a change made specifically to reduce Melanotan II’s prolonged erection and nausea side effects. Bremelanotide is FDA-approved, under the brand name Vyleesi, as an on-demand subcutaneous injection for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, and it is not approved for any use in men.

The approval and its evidence

FDA approval rested on the RECONNECT program, two parallel 24-week randomized, double-blind, placebo-controlled Phase 3 trials (studies 301 and 302) in premenopausal women with HSDD, using a 1.75 mg subcutaneous dose self-administered at least 45 minutes before anticipated sexual activity, as needed, no more than once in 24 hours and no more than 8 times per month. A 52-week open-label extension in patients who completed the core trials, published in 2019, reported sustained improvement in desire scores and no new safety signals; the most common treatment-related adverse events were nausea (40.4% over the full extension), flushing (20.6%) and headache (12.0%).

Nausea is dose-limiting and common enough that the label recommends against use in patients with uncontrolled hypertension or known cardiovascular disease, and bremelanotide transiently raises blood pressure after each dose.

What is not established

Efficacy or safety in men. Bremelanotide has no FDA approval and no published Phase 3 program for male sexual dysfunction; interest in “PT-141 for men” circulates in research-peptide material without the trial base that exists for the approved female indication.

Whether more frequent dosing than the approved as-needed schedule, as sometimes described in circulating protocols, changes the tachyphylaxis, blood-pressure or nausea profile established in the pivotal trials, which tested a strict as-needed limit.

What is not known

Efficacy or safety in men. There is no FDA approval and no published Phase 3 trial for male sexual dysfunction.

Whether more frequent or scheduled dosing than the approved as-needed limit changes the tachyphylaxis, blood pressure or nausea profile established in the pivotal trials.

Doses used in published research

No published study has administered this compound to a human being, so no dose appears in the literature and none has been established.

Amounts above record what a named source reported administering in a study. They are not a recommendation, not a protocol, and not instructions.

Converting a vial and a syringe into a draw volume is a separate, mechanical question from what amount to use. The reconstitution calculator does that arithmetic for peptide, HCG, and HGH vials.

What circulates E5

Figures reported online. Not dosing, not verified, not endorsed.
Reported use	Route	Amount reported	Frequency	Reported length
Libido/sexual function, general (including off-label male use)	Subcutaneous	1 to 2 mg per dose	As needed, sometimes more frequent than the approved limit	Ongoing

Circulating dosing for PT-141, 1 to 2 mg subcutaneously as needed, roughly matches the FDA-approved 1.75 mg dose for the approved indication (HSDD in premenopausal women). Where it diverges is population and frequency: circulating material commonly describes male use and more frequent dosing than the approved once-per-24-hours, 8-times-per-month limit, neither of which was tested in the pivotal trials this drug was approved on.

Recorded as an observation about what is published elsewhere. No figure here is a dose, a protocol, or a recommendation, and nothing in this section is evidence that any amount is safe or effective.