Brain & sleep MC4R agonist
PT-141
Regulatory status
Status at a glance
503A compounding status
Not nominated
We found no pending nomination for the 503A bulks list. Unless the substance has another legal pathway (for example, a USP monograph or use in an FDA-approved drug), 503A pharmacies generally may not compound with it.
- FDA approval
- Not FDA-approved for any use
- 503B outsourcing
- Not determined
- Anti-doping (WADA)
- Not on the WADA Prohibited List
- DEA schedule
- Not a controlled substance
About peptide status
Most peptides discussed here are not FDA-approved for any use, and products labeled “research use only” are not for human use. Removal from Category 2 does not authorize compounding. PCAC votes are non-binding recommendations; FDA and HHS make the final decisions.
This is not medical or legal advice, and we do not publish dosing, sourcing or reconstitution information. Talk with a licensed clinician before using any peptide.
If you think you are having a medical emergency, call 911.
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.
At a glance
- What it is
- Gray-market/compounded name for bremelanotide, sold for libido in both sexes
- Approved product
- Vyleesi (bremelanotide), FDA-approved only for premenopausal women with HSDD
- Gray-market product
- Not the approved product and not FDA quality-controlled
- How it works
- MC4R agonist acting in the brain rather than on blood flow
- Evidence strength
- Low research
Summary
PT-141 is the gray-market name for bremelanotide. Learn how it works in the brain, what Vyleesi is approved for, and why the evidence for broader use is thin.
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?
Safety note
Status: Not as sold on the gray market. The approved product and the gray-market product differ on status and population: Attribute | Vyleesi (bremelanotide) | Gray-market "PT-141" FDA status | FDA-approved in 2019 | An unapproved use and an unregulated source, not Vyleesi, and not FDA quality-controlled Population | Premenopausal women with HSDD | Marketed 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.
Category: Wellness and performance · Primary body area: Brain & sleep
Not as sold on the gray market. The approved product and the gray-market product differ on status and population:
| Attribute | Vyleesi (bremelanotide) | Gray-market "PT-141" |
|---|---|---|
| FDA status | FDA-approved in 2019 | An unapproved use and an unregulated source, not Vyleesi, and not FDA quality-controlled |
| Population | Premenopausal women with HSDD | Marketed 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?
Editor’s note
Evidence strength: Low research
For the gray-market product and use, there is no controlled human evidence; the approved drug has Phase 3 data only in one narrow population, with modest and contested effect sizes.
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 review), and independent analysis 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.
Sources: a review of bremelanotide's approval (Dhillon and Keam, Drugs, 2019, DOI: 10.1007/s40265-019-01187-w) and an independent critique of the trial outcomes (Spielmans and Ellefson, Journal of Sex Research, 2024, DOI: 10.1080/00224499.2023.2175192), 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.
Registered human trials
0 registered human trials on ClinicalTrials.gov that we reviewed
Sources
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- [12]
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Bremelanotide is a synthetic seven-amino acid peptide that activates melanocortin receptors in the brain to increase sexual desire, unlike blood-flow drugs such as sildenafil. In the two RECONNECT phase 3 trials of 1,267 premenopausal women with hypoactive sexual desire disorder (HSDD), it raised the desire score 0.35 points more than placebo and reduced desire-related distress 0.33 points more (both P<.001) over 24 weeks. It is FDA-approved as Vyleesi, a prescription self-injection for acquired, generalized HSDD. Versions sold online as PT-141 are not the FDA-approved product and are not quality-controlled.
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