Libido

PT-141

Approved in the US for one useApproved drugBremelanotideVyleesi

A peptide that acts on melanocortin receptors in the brain to increase sexual desire. As bremelanotide (Vyleesi) it's FDA-approved, used as needed, for premenopausal women with low sexual desire. Studies in men are small. Nausea is very common.

Canada
Not authorized; seized by Health Canada in 2025
United States
Approved (Vyleesi, 2019) for low sexual desire (HSDD) in premenopausal women

Download profile Opens in Vialchemy on your iPhone, where it's added to your Library as your own.

Not medical advice — talk to your doctor before making medical decisions.

At a glance

Class
Libido (melanocortin agonist)
Mechanism
Acts on brain melanocortin receptors (MC3R/MC4R)
Evidence
Approved drug (women with HSDD); small studies in men
Canada
Not authorized
Us
Approved (Vyleesi)
Half Life
About 2-3 hours
Routes
SubQ (as needed), nasal (unapproved)
Common Side Effects
Nausea (about 40% in trials), flushing, headache, vomiting
Key Cautions
Temporary blood pressure rise; skin darkening with repeated use

What the research says

  • Blood pressure?

    It raises blood pressure and lowers heart rate for several hours after a dose. The label says not to use it with uncontrolled high blood pressure or heart disease, and to use no more than once in 24 hours.

  • Skin darkening?

    Repeated use can cause dark patches on the face, gums or breasts, which may not fully fade.

  • Naltrexone?

    Bremelanotide can lower levels of oral naltrexone, which matters for anyone using it for alcohol or opioid dependence.

  • Works for men?

    Small studies, including in erectile dysfunction, showed some effect, but it's not approved for men.

Get medical care if

  • Redness, heat, swelling or pus at a site that spreads or comes with fever
  • Hives, swelling of the face or throat, or trouble breathing (call 911)
  • Severe headache, chest pain or a pounding heartbeat after a dose

Buying and quality

  • Not authorized by Health Canada. Products sold online as "research use only" are illegal to sell for human use in Canada, and the label doesn't change that.
  • Health Canada warns these products may contain too much, too little or none of the peptide, plus contaminants like endotoxins, solvents, heavy metals or bacteria.
  • A certificate of analysis (COA) from the seller isn't independent proof. A 98% purity result still leaves 2% unidentified.
  • If you use it anyway: one clean needle per injection, sterile technique, label and date every vial, and stop if a site gets hot, red and spreading.

Dose calculator

Doses are set with your prescriber. This converts a dose you already have into what to draw; it doesn't recommend one. Check every number against your syringe and your vial's label.

Doses left in the vial
A blend vial

Not medical advice — talk to your doctor before making medical decisions.

Sources

Researched 2026-10-27. Trial results and approval status change.

  1. Health Canada: Unauthorized injectable peptides seized, Calgary (Apr 2025)
  2. PubMed: bremelanotide studies
  3. ClinicalTrials.gov: bremelanotide

General education, not medical advice. Nothing here is a dose recommendation. Doses, schedules and changes are set with a prescriber.