PT-141: An Approved Drug Whose Label Says It Is Not for Performance, Sold Beside the Steroids

There is no performance evidence for PT-141. Not thin evidence, not animal evidence — none, and the approved label says so from the other direction.

That would normally end the page. It does not, because this compound turns up in the supply chain this site covers, and the reason it turns up has nothing to do with what has been measured.

What it is, and what the approval covers

PT-141 is bremelanotide, a melanocortin receptor agonist. It is an approved American medicine: Vyleesi, first approved in 2019, its current label held by Cosette Pharmaceuticals and published in November 2025.

The indication is the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder. Then the label's own Limitations of Use:

VYLEESI is not indicated for the treatment of HSDD in postmenopausal women or in men. VYLEESI is not indicated to enhance sexual performance.

Two sentences that exclude most of the market this compound actually has. Peptide Lexicon's compound entry for bremelanotide covers the approval and its mechanism in full; what follows is the part that belongs on a training publication.

The census, and the five records that look relevant and are not

PubMed, searched 2026-09-15:

Fourteen randomized trials exist and none has a muscle, strength, body-composition, endurance or recovery endpoint. They are trials of sexual desire.

The five records that matched performance terms are worth listing, because a count of five looks like a literature and is not one:

1. A 2026 review of therapeutic peptides in aesthetic, metabolic and endocrine conditions.
2. A 2021 forensic analysis of black-market samples (below — the most useful paper here).
3. A 2014 review of melanocortin agonists in sexual dysfunction.
4. A 2012 case report of systemic toxicity after Melanotan II, a different compound.
5. A 2008 study of neuropeptides on rabbit vaginal wall and vaginal artery smooth muscle — the word "muscle" that produced the match.

That is the same trap this site hit on the creatine and collagen literatures: a record count is not an evidence count until someone reads what the records are about.

Why it is here: the forensic paper

Forensic toxicologists at the Università Cattolica del Sacro Cuore in Rome, working with the Venice laboratory, characterised bremelanotide and melanotan II in eight unknown samples confiscated by police, seized alongside anabolic steroids, hormone modulators, sexual enhancers and stimulants, and described in their own paper as intended for the black market of bodybuilders.

Two details in that sentence carry the page.

The first is the company it keeps. This is not a compound that reaches a gym by accident; it is inventory in the same stash as the steroids, sold by the same suppliers, to the same customers.

The second is quieter and more useful: the identification had to be done without reference standards, because these products are not legally marketed in the form seized. A laboratory with an Orbitrap mass spectrometer had to derive what the substance was from its isotopic pattern and fragmentation. Nobody buying a vial can do that, and the purity question is not answerable at the point of sale.

The label's most transferable number: frequency

This is the part a reader who has already decided is least likely to have seen, and it is the strongest thing on the label.

The safety data describe infrequent use. In the phase 3 programme — two identical 24-week trials, 1,247 premenopausal women, 1.75 mg by autoinjector as needed — most patients dosed two to three times a month, and no more than once a week. The label permits no more than one dose in 24 hours and states that more than 8 doses per month is not recommended, because more frequent dosing raises both the pigmentation risk and the number of hours each month spent with elevated blood pressure.

Now the pigmentation numbers, which are reported by dosing pattern:

The affected sites named on the label include the face, gums and breasts. People with dark skin were more likely to be affected. And the label states plainly that resolution after stopping was not confirmed in all patients.

A 1% risk and a 38% risk are the same drug at two frequencies. Any market that uses a compound more often than its trials did is operating outside the data that produced those trials' safety profile — and on this one the difference is documented rather than inferred.

The rest of the labelled effects, reported as the label reports them

• Blood pressure and heart rate. Transient maximal increases of 6 mmHg systolic and 3 mmHg diastolic, peaking 2 to 4 hours after a dose, with heart rate falling by up to 5 beats per minute; both usually back to baseline within 12 hours. Contraindicated in uncontrolled hypertension or known cardiovascular disease, and not recommended at high cardiovascular risk.
• Nausea, 40% of treated patients against 1% on placebo — median onset within an hour, lasting about two hours, 21% after the first dose falling to about 3% after later ones. 13% took an anti-emetic and 8% left the trials because of it.
• Flushing 20.3%, injection-site reactions 13.2%, headache 11.3%, vomiting 4.8%.
• Gastric emptying. The label states the drug may slow it and so reduce the rate and extent of absorption of oral medications taken at the same time, and that it significantly decreases systemic exposure to oral naltrexone, which should not be used alongside it.

For an audience whose routine is built on oral supplements and timing, that last point is the one that is never mentioned in the places this compound is sold.

Sport: what we can and cannot say

We could not open WADA's Prohibited List today. Their server returned an empty response to every request on 2026-09-15, so nothing here is quoted from it, and we will not paraphrase a document we did not read.

What can be said is narrower and still worth having: bremelanotide does not appear in the published screening panels this site has already covered, including the Cologne laboratory's method for peptides under 2 kDa, which names seventeen compounds by name. Absence from a screening method is not a statement about the List — it is a statement about what one published assay looks for. Under the anti-doping codes the athlete is responsible for whatever is in the sample, whatever the label said. Our drug-testing page sets out how those panels work and where a finding realistically comes from, and the legal position for athletes covers the regulatory side.

The adjacent compound, named deliberately

Melanotan II keeps appearing in the same searches and the same seizures, and its literature contains the harm a training audience will recognise: a 39-year-old man who injected 6 mg bought online — six times his own stated starting dose — arrived at hospital two hours later with a heart rate that peaked at 146, a creatine kinase of 1,760 IU/L that rose to 17,773 IU/L within twelve hours, raised creatinine and troponin, and rhabdomyolysis treated with intravenous fluids and bicarbonate over three days in intensive care. The substance was confirmed by mass spectrometry against a purchased standard.

That is evidence about Melanotan II, not about PT-141. The two are different molecules with different receptor selectivity, and this site has made the same point in the other direction about carrying one compound's record across to another. It is named here for one reason: the suppliers and the seizures carry both, so anyone researching one will meet the other, and the honest thing is to say which findings belong to which molecule.

Where this leaves it

An approved drug with a real label, a real trial programme and a genuine indication — none of which is performance, and the label says so in its own words. Its entire connection to this audience is distribution. The most useful facts on it for anyone here are the ones the label reports about frequency: a pigmentation risk that runs from 1% to 38% depending on how often it is used, a blood-pressure effect that peaks two to four hours after a dose, and an effect on stomach emptying that reaches everything taken by mouth.

This page will be updated if a performance endpoint is ever studied. On today's count, the number of such studies is zero.

Sources

• VYLEESI (bremelanotide) injection, prescribing information, Cosette Pharmaceuticals, Inc. Retrieved from DailyMed 2026-09-15 — indication and Limitations of Use, contraindications, blood-pressure and heart-rate data, focal hyperpigmentation at monthly and daily dosing, nausea and other adverse reactions, drug interactions, phase 3 design (NCT02333071, NCT02338960).
• Mestria S, Odoardi S, Frison G, Strano Rossi S. LC-HRMS characterization of the skin pigmentation and sexual enhancers melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs. Drug Test Anal 2021;13(4):876–82. PMID 33245851.
• Nelson ME, Bryant SM, Aks SE. Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Clin Toxicol (Phila) 2012;50(10):1169–73. PMID 23121206 — a case report about Melanotan II, not bremelanotide.
• PubMed counts, run 2026-09-15 via the NCBI E-utilities esearch endpoint: bremelanotide[tiab] OR "PT-141"[tiab] — 112 records; with "randomized controlled trial"[pt] — 14; with exercise, athlete, muscle, performance, strength or body-composition terms — 5; with doping or sport terms — 0.
• WADA Prohibited List: not quoted. wada-ama.org/en/prohibited-list returned an empty response to every automated request on 2026-09-15.