PT-141
MC4R agonist
Also PT141, PT 141, Bremelanotide, Vyleesi, PT-141 peptide, Bremelanotide acetate
- Evidence
- BSome human evidence
- FDA status
- Not approvedas of 2026-10-26
- Route
- Injection
- Studies cited
- 7 human0 animal or cell
It is sold online as a sex-drive booster, mostly to men. The approved form, bremelanotide, was tested in 1,267 women with small gains; for men there are only two small studies from 2004.
Sold for
PT-141 is sold on the gray market as a libido and erection booster for men and women that works through the brain instead of blood flow.
Studies say
Two phase 3 trials support a modest effect on sexual desire in premenopausal women with HSDD, which is what the FDA approved; the evidence in men is two small 2004 studies, one nasal and one injected, from a program that was abandoned, and nausea affects about 40 percent of users.
Why grade B. For the approved use there are two randomized, placebo-controlled phase 3 trials (RECONNECT, 1,267 women combined), which is A-level evidence, though a re-analysis argues the effect on desire is small. For the use PT-141 is actually sold for online, libido and erections in men, the evidence is two small 2004 studies, one of a nasal spray that was later abandoned and one of an injection, so the compound as marketed sits at B. 2561011
FDA. PT-141 is the development code for bremelanotide, which the FDA approved in June 2019 as Vyleesi for premenopausal women with acquired, generalized hypoactive sexual desire disorder. Products sold online as PT-141 are not Vyleesi, are not approved by the FDA for any use, and are sold as research chemicals, most often to men, a population the drug was never approved for. 17
Written from 12 cited sources. Fact-checked 2026-10-27: 24 claims checked, 6 corrected. Last refreshed 2026-10-27. Not physician reviewed.
What this means for you
- What people take it for
- Sex drive and erections
- Can a US doctor prescribe it?
- Yes, FDA approved as bremelanotide (Vyleesi) for low desire in women before menopause. Not approved for men.
- Properly tested in people?
- Partly: two trials in 1,267 women, but for men only two small studies from 2004.
Evidence checklist
- Randomised controlled trial RECONNECT trials, placebo-controlledyes
- Human study over 100 people RECONNECT, 1,267 premenopausal womenyes
- More than one research group Phase 3 by sponsor; one reanalysisno
- Clinical outcomes, not surrogate markers Questionnaire scores; no extra satisfying eventsno
- Human safety data beyond case reports Nausea ~40%; blood pressure effects in trialsyes
Drawn from the cited studies below. A dash means the sources give no information.
What it is
PT-141 is bremelanotide, a cyclic seven-amino-acid peptide derived from melanotan II, which itself was derived from the pigment hormone alpha-MSH. Researchers testing melanotan II as a tanning agent in the 1990s noticed it caused erections, and Palatin Technologies split off a version without the tanning effect for sexual dysfunction. 18
Palatin first developed it as a nasal spray for erectile dysfunction in men. Those trials were stopped in 2007 after blood pressure increases, and the program was redirected to a subcutaneous autoinjector for women with low desire. The FDA approved that product, Vyleesi, in June 2019, the second drug after flibanserin (Addyi) for hypoactive sexual desire disorder in premenopausal women. 178
How it works
Bremelanotide activates melanocortin receptors in the brain, mainly the MC4 receptor, in hypothalamic circuits that regulate sexual motivation. Activation appears to increase dopamine release in the medial preoptic area, a region tied to sexual arousal in animal studies. A functional MRI crossover study in women with HSDD found that bremelanotide altered activity in brain regions involved in sexual response while viewing erotic stimuli. This is a different route from sildenafil (Viagra) and tadalafil, which act in the penis by blocking the enzyme that breaks down cyclic GMP, so they improve blood flow and do not act on desire. 349
What human research shows
The RECONNECT program comprised two identical 24-week randomized, double-blind, placebo-controlled trials in 1,267 premenopausal women with HSDD. Both met their co-primary endpoints: bremelanotide improved the desire domain of the Female Sexual Function Index by about 0.3 to 0.4 points more than placebo on a 1.2-to-6 scale, and reduced distress scores by a similar small margin. It did not increase the number of satisfying sexual events. Improvements persisted in a 52-week open-label extension, which 684 women entered and 272 completed. An earlier 12-week phase 2b dose-finding trial in 327 women had used satisfying sexual events as its primary endpoint and found a small increase at the higher doses, 0.7 more per month against 0.2 on placebo. 5612
A later independent analysis of the RECONNECT data argued that the desire and distress scales used as endpoints have little evidence of validity in women with HSDD. It also analysed eight of the eleven registered efficacy outcomes that had not been published, including total sexual function and distress scores, and found effects ranging from nil to small. 2
In men, a 2004 placebo-controlled study in healthy volunteers and in men with erectile dysfunction who responded to sildenafil found that intranasal bremelanotide produced erections, measured by penile rigidity monitoring, above a threshold dose. A second 2004 study gave bremelanotide by subcutaneous injection to healthy men and, in a placebo-controlled crossover, to men with erectile dysfunction who had not responded adequately to sildenafil, and reported statistically significant erectile responses in both groups. Both studies were short and small, and no further trials in men were completed after the blood pressure signal. 1011
| Study | Model | Finding |
|---|---|---|
| RECONNECT phase 3 trials | Humans, n=1,267 premenopausal women with HSDD, two randomized, double-blind, placebo-controlled trials, 24 weeks | Small but statistically significant improvements in desire and distress scores versus placebo; no increase in satisfying sexual events. 5 |
| RECONNECT open-label extension | Humans, 52-week open-label follow-on | Improvements in desire and distress were maintained among the 272 of 684 women who completed it; nausea, in 40%, was the commonest drug-related adverse event. 6 |
| Independent re-analysis of RECONNECT | Analysis of published and unpublished RECONNECT outcomes | Found little evidence that the trial efficacy scales are valid in HSDD and effect sizes from nil to small on the previously unpublished outcomes. 2 |
| Intranasal bremelanotide in men | Humans, healthy men and men with erectile dysfunction who responded to sildenafil, placebo-controlled | Intranasal bremelanotide produced statistically significant erections compared with placebo above a threshold dose. 10 |
| Subcutaneous bremelanotide in sildenafil non-responders | Humans, healthy men and men with an inadequate response to sildenafil, placebo-controlled crossover in the patient study | Injected bremelanotide produced statistically significant erectile responses in both groups. 11 |
Safety
Nausea is the dominant side effect: about 40 percent of women in the phase 3 trials reported it, usually after the first doses, and around 8 percent stopped treatment because of it. Flushing, injection site reactions, headache and vomiting are also common. Bremelanotide causes a transient rise in blood pressure of a few mmHg with a drop in heart rate for several hours after each dose; the label contraindicates it in uncontrolled hypertension and cardiovascular disease and limits how often it can be used within a day and within a month. About 1 percent of women developed focal darkening of the skin or gums, more often with daily use, which did not always resolve. Vyleesi also slows stomach emptying and can reduce absorption of oral drugs taken around the same time. None of this safety data covers the gray-market product, whose purity and dose are unverified, or men, in whom only two short 2004 studies exist. 135810
Questions for your clinician
- Is the product I am looking at actually Vyleesi, or an unregulated PT-141?
- Is there any good trial in men, the group this is often sold to?
- Do my blood pressure or heart history rule it out?
Questions people ask
What is PT-141, and how does it set itself apart from Viagra or Cialis?
PT-141 is bremelanotide, a melanocortin receptor agonist that acts in the brain on circuits controlling sexual desire. Sildenafil and tadalafil act on blood vessels in the penis by blocking the enzyme that breaks down cyclic GMP, so they help erections but do nothing for desire. Bremelanotide was approved for low desire in women; it was never approved for erectile dysfunction. 347
What were the results of the RECONNECT trials?
Across 1,267 premenopausal women, bremelanotide improved desire scores by about 0.3 to 0.4 points on a 6-point scale and lowered distress scores modestly compared with placebo over 24 weeks. The number of satisfying sexual events did not increase. A re-analysis contends these differences are too small for most women to notice. 25
Who is it FDA-approved for?
Premenopausal women with acquired, generalized hypoactive sexual desire disorder, meaning low desire that developed after a period of normal desire, occurs regardless of partner or situation, causes distress, and is not explained by a medical or psychiatric condition, relationship problems or another drug. It is not approved for men or postmenopausal women. 17
Has PT-141 been tested in men?
Two small studies from 2004 found that it produced erections, one with a nasal spray and one with an injection that also worked in men who had not responded to sildenafil. The men's program was halted in 2007 because of blood pressure increases, and no later trials in men were done, so there is no evidence on long-term use or on sexual outcomes beyond the laboratory. 11011
Which adverse effects have been recorded for PT-141?
Nausea in about 40 percent of users, flushing, injection site reactions and headache, a short-lived rise in blood pressure after each dose, and in about 1 percent of users patches of darkened skin or gums that may not fade. The label limits how often it can be used and excludes people with uncontrolled hypertension or heart disease. 358
Citations
- Dhillon 2019, Drugs: bremelanotide, first approval doi.org
- Spielmans 2024, J Sex Res: small effects, questionable outcomes, bremelanotide for HSDD doi.org
- Vyleesi (bremelanotide) prescribing information, DailyMed dailymed.nlm.nih.gov
- Sildenafil prescribing information, DailyMed dailymed.nlm.nih.gov
- Kingsberg 2019, Obstet Gynecol: bremelanotide for HSDD in premenopausal women, two randomized phase 3 trials (RECONNECT) doi.org
- Simon 2019, Obstet Gynecol: long-term safety and efficacy of bremelanotide, RECONNECT open-label extension doi.org
- FDA Drugs@FDA: Vyleesi NDA 210557 approval record accessdata.fda.gov
- Ann Pharmacother 2024: review of bremelanotide for HSDD doi.org
- J Clin Invest 2022: crossover fMRI study of bremelanotide in women with HSDD doi.org
- Diamond 2004, Int J Impot Res: intranasal PT-141 and erectile response in men doi.org
- Rosen 2004, Int J Impot Res: subcutaneous PT-141 in healthy men and men with an inadequate response to sildenafil doi.org
- Clayton 2016, Womens Health: bremelanotide phase 2b dose-finding trial in HSDD doi.org