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Sexual health & melanocortin

PT-141 (bremelanotide)

Also called bremelanotide, Vyleesi, PT-141

Bremelanotide, often called PT-141, is a lab-made peptide that acts on melanocortin receptors in the brain. The FDA approved it in 2019 as Vyleesi, an as-needed injection for premenopausal women with low sexual desire that causes distress. Nausea is its most common side effect.

FDA-approvedApproved by the FDA for at least one use after large human trials.

All printable flashcards

Drawn from its published sequence: 7 residues, one bead each. Dashed arcs are ring bonds.

Overview

Bremelanotide, often called PT-141, is a lab-made peptide that acts on melanocortin receptors in the brain. The FDA approved it in 2019 as Vyleesi, an as-needed injection for premenopausal women with low sexual desire that causes distress. Nausea is its most common side effect.

How it works

Established that it is a melanocortin receptor agonist, mainly at MC1R and MC4R at therapeutic doses (MC4R is found on brain neurons). The FDA label states that how it improves low sexual desire is unknown. Its action at MC1R on pigment cells explains the darkening of skin patches some people see.

What research shows

  • Two identical 24-week placebo-controlled Phase 3 trials (1,247 premenopausal women with HSDD) plus a 52-week open-label extension 1.
  • About 25% on bremelanotide improved desire scores by ≥1.2 points vs 17% on placebo; distress scores fell in 35% vs 31%; sexual satisfaction did not improve 2.

Doses studied in people

Study or labelDose usedSource
FDA label (Vyleesi), HSDD in premenopausal women1.75 mg subcutaneously as needed ≥45 minutes before sexual activity; no more than 1 dose per 24 hours; more than 8 doses per month not recommended1

The only verified dose is the FDA-labeled 1.75 mg; the label says to stop after 8 weeks if there is no improvement.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Weekly protocol

How the schedule looks week by week. Each chart says where it comes from: a prescribing label, a clinical trial, or a protocol commonly reported online.

Vyleesi label dosing

Prescribing label

One week

D1D2D3D4D5D6D7

As needed, at least 45 minutes before sexual activity · Subcutaneous injection (autoinjector)

Dose by week

1.75 mg per dosewk 1+
Course
Stop after 8 weeks if there is no improvement
Note
No more than 1 dose in 24 hours; more than 8 doses a month is not recommended.
Source
VYLEESI (bremelanotide) prescribing information (FDALabel)

Reference only, not a recommendation. Label and trial schedules were set for specific patients under medical supervision. Use the calculator only to understand the arithmetic.

Safety

  • Nausea 40% (vs 1.3% placebo), flushing 20%, injection-site reactions 13%, headache 11%, vomiting 4.8% 1.
  • Temporary rise in blood pressure and drop in heart rate after each dose; contraindicated with uncontrolled high blood pressure or known cardiovascular disease 1.
  • Focal hyperpigmentation (face, gums, breasts), more likely with darker skin and daily use 1.
  • Can sharply lower blood levels of oral naltrexone; avoid with naltrexone for alcohol or opioid use disorder 1.
  • Not approved for men, postmenopausal women, or to enhance sexual performance 1.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

History

Developed as a relative of melanotan II. FDA approved Vyleesi on June 21, 2019 for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women; it was initially marketed by AMAG Pharmaceuticals.

Common questions

Is PT-141 FDA-approved?

Yes. It was approved as Vyleesi on June 21, 2019, for acquired, generalized low sexual desire with distress (HSDD) in premenopausal women 12. It is not approved for men, postmenopausal women or to enhance sexual performance 1.

How well does it work?

In two 24-week trials of 1,247 premenopausal women, about 25% improved their desire scores versus 17% on placebo 12. Sexual satisfaction did not improve 2.

What dose is on the label?

The FDA label lists 1.75 mg injected under the skin as needed, at least 45 minutes before sexual activity, no more than once in 24 hours 1. More than 8 doses a month is not recommended, and the label says to stop after 8 weeks without improvement 1.

What are the side effects?

Nausea affected 40% (versus 1.3% on placebo), followed by flushing, injection-site reactions and headache 1. Blood pressure rises briefly after each dose, so it is not for people with uncontrolled high blood pressure or known heart disease 1.

Can PT-141 darken the skin?

Yes. Dark patches on the face, gums or breasts can occur, more often with darker skin and daily use 1.

Is PT-141 banned in sport?

It is not named on WADA's 2026 list, and as an approved drug it does not fall under the S0 non-approved substances rule 4.

Sold in blends and stacks

Melanotan II + PT-141

Related compounds

Sexual health & melanocortinEarly human dataFlashcard

Melanotan II

MT-II · MT2

Melanotan II is a lab-made peptide that copies a skin-darkening hormone (α-MSH).

Sexual health & melanocortinFDA-approvedFlashcard

Afamelanotide

Scenesse · [Nle4, D-Phe7]-α-MSH

Afamelanotide is a lab-made, longer-lasting copy of the skin-darkening hormone α-MSH.

Hormonal & reproductiveFDA-approvedFlashcard

Oxytocin

Pitocin · OT

Oxytocin is a natural hormone made in the brain that triggers labor contractions and milk let-down, and it also plays a role in social bonding.

Sources

  1. Vyleesi (bremelanotide injection) Prescribing Information — FDALabel FDA label
  2. Healio: FDA approves Vyleesi for women with low sexual desire (June 21, 2019) Journal
  3. FDA: Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (updated May 14, 2026) Regulatory
  4. WADA 2026 Prohibited List (official English text, Dutch Treaty Series Trb. 2026, 25) Regulatory

Last reviewed 2026-10-25 · How we research · Found an error? See our corrections policy.