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Not FDA-approved

Brain & sleep

PT-141

Also called bremelanotide (see approved)

EvidenceLow research
ClassMC4R agonist

Key takeaway

PT-141 is the gray-market name for bremelanotide, a melanocortin peptide that acts in the brain to affect sexual desire. The approved version, Vyleesi, is FDA-approved only for low sexual desire in certain premenopausal women; the "PT-141" sold online for libido in both sexes is not that product and is not quality-controlled. As of 2026 gray-market PT-141 is not FDA-approved.

Written by
Nav SekhonResearch Lead
Reviewed by
William Maish, MD MBA MPHClinical Product Lead
Published
October 13, 2025
Last updated
October 5, 2026

At a glance

What it isGray-market/compounded name for bremelanotide, sold for libido in both sexes
Approved productVyleesi (bremelanotide), FDA-approved only for premenopausal women with HSDD
Gray-market productNot the approved product and not FDA quality-controlled
How it worksMC4R agonist acting in the brain rather than on blood flow
Evidence strengthLow research

What is PT-141?

PT-141 is the research and gray-market name for bremelanotide, a cyclic melanocortin peptide. The FDA-approved form is sold as Vyleesi for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. The "PT-141" sold through research-chemical and compounding channels, often for libido in both men and women, is not the approved product.

How does it work?

PT-141 (bremelanotide) activates melanocortin receptors, chiefly MC4R, in brain regions that help regulate sexual desire. This is a central mechanism, different from erectile-dysfunction drugs that act on blood flow. This describes the proposed mechanism, separate from whether the unregulated product is effective or safe as sold.

Is it FDA-approved?

Not as sold on the gray market. The approved product and the gray-market product differ on status and population:

AttributeVyleesi (bremelanotide)Gray-market "PT-141"
FDA statusFDA-approved in 2019An unapproved use and an unregulated source, not Vyleesi, and not FDA quality-controlled
PopulationPremenopausal women with HSDDMarketed for men and for general libido

Vyleesi is given as an on-demand self-injection. Gray-market "PT-141" was not among the peptides reviewed favorably at the 2026 FDA compounding advisory meetings.

What does the research show?

The rigorous human data belong to the approved product and a narrow population. According to PubMed, bremelanotide's approval rested on Phase 3 trials in premenopausal women with HSDD (first-approval review1), and independent analysis2 has characterized the benefit as statistically modest with contested outcome measures. There are no controlled trials supporting the gray-market "PT-141" product for broader libido use in both sexes, so its benefit and safety as sold are unestablished.

Also in the library

More for brain & sleep

Sources: a review of bremelanotide's approval (Dhillon and Keam, Drugs, 2019, DOI: 10.1007/s40265-019-01187-w1) and an independent critique of the trial outcomes (Spielmans and Ellefson, Journal of Sex Research, 2024, DOI: 10.1080/00224499.2023.21751922), indexed on PubMed; and FDA records for the approved product Vyleesi. This document is educational, is not medical advice or a health claim, and is not an offer to sell any product.