PT-141
PT-141 (Bremelanotide)
Also called bremelanotide, Vyleesi, PT141
The approved drug that acts on desire rather than blood flow
PT-141, sold as Vyleesi, is an approved medicine for low sexual desire in premenopausal women. It is unusual among these compounds in acting on the brain rather than on blood flow, which is how it differs from Viagra. It is labelled for as-needed use rather than daily.
An injection approved as Vyleesi for acquired, generalised hypoactive sexual desire disorder (low sexual desire) in premenopausal women. Viagra and its relatives work on blood flow; this acts on the part of the brain that sets drives like hunger and arousal, which is why it was studied for a condition where blood flow was never the problem.
- Half-life
- About 2.7 hours
- Route studied
- Subcutaneous injection (Vyleesi label)
- Status
- Prescription (Vyleesi, for low sexual desire in premenopausal women)
Tested in several human trials
121 papers · 16 clinical trials
What PT-141 has been studied for
The reasons people look it up, roughly in order of how often, and what research exists for each. Interest in a use is not evidence that it works; the evidence is stated under each one.
- Low sexual desire in women
- Its approved use, in premenopausal women with hypoactive sexual desire disorder.
- Erectile difficulty
- Studied in men in earlier trials of a nasal form. It is not approved for men, and the trials behind approval were in women.
Mechanism of Action
How PT-141 works
Viagra and the drugs like it work on plumbing. They improve blood flow, which helps if blood flow is the problem, and does nothing at all if the problem is that you do not want to.
PT-141 works on the wanting.
Where it acts
It reaches receptors in the hypothalamus, a part of the brain involved in setting drives like hunger, temperature and sexual motivation. Rather than opening blood vessels downstream, it acts upstream, on the signal that starts the whole sequence.
That is why it was developed and approved for low sexual desire in premenopausal women, a condition where blood flow was never the issue. It is labelled for use as needed rather than daily.
What that mechanism costs
The receptors it acts on are not only in the brain. The same family governs skin pigment, which is why repeated use can darken patches of skin.
It also raises blood pressure briefly while slowing heart rate. That effect is the reason the nasal version was abandoned: getting enough through the nose meant doses where the cardiovascular effect stopped being manageable. The injection at its approved dose produces a much smaller rise, but the label still advises against use with uncontrolled high blood pressure or known cardiovascular disease.
How well does it work
It is approved, which puts it ahead of most things on this site. It is also genuinely debated: a 2024 analysis went back to the approval trials and argued the questionnaires used to measure success were poorly validated and the actual improvement modest.
Both things are true. Approval means it cleared a bar, not that the effect is large.
PT-141 side effects: what studies reported
Nausea is the side effect to know about: roughly four in ten participants in the RECONNECT trials reported it.
Most commonly reported
- Nausea, reported by roughly 40% in the phase 3 trials
- Flushing
- Headache
- Injection-site reactions
- A stuffy nose
Worth keeping an eye on
- A short-lived rise in blood pressure with a small drop in heart rate
- Darkening of skin, freckles, moles or gums, reported more with frequent use, since it acts on the same receptors that control pigment
- The Vyleesi label limits use to one dose in 24 hours and eight doses a month
Reasons to check first
- Uncontrolled high blood pressure or known cardiovascular disease, because of the transient pressure rise
Dose-related findings. In development studies, nausea and the blood pressure effect were more frequent at higher doses.
Source: RECONNECT trials for bremelanotide, plus prescribing experience. This is a summary of published findings, not a complete safety profile and not medical advice. Questions about PT-141 belong with a licensed clinician who knows your history.
Your Genetics & PT-141
The genes involved in how PT-141 works
PT-141 works through the receptors these genes build, and the genes vary from person to person. Researchers have linked some of that variation to differences in how people respond. A DNA report tells you which versions you carry.
MC4R · ••
MC4R builds one of the melanocortin receptors bremelanotide acts on. The rs17782313 variant near MC4R is associated with appetite and body weight in population studies. No study has tested whether it changes response to bremelanotide.
MC4R · ••
A second common MC4R variant, associated with slightly lower obesity risk in population studies. It has not been studied with bremelanotide.
COMT · ••
Builds an enzyme that clears catecholamines such as dopamine; the Val158Met variant is widely studied in brain research. Any link between it and bremelanotide's side effects is a hypothesis; it has not been tested.
The dots after each gene are where your own result goes. Your report fills them in with the two letters you carry at that position.
Which of these variants do you carry?
Your report reads the DNA file you already have against this research.
Often discussed alongside
Compounds that come up next to PT-141 in research and discussion. Each has its own page. None of this is a suggestion to combine them.
Oxytocin
also studied for sexual functionModerate EvidenceOxytocin (The Bonding Hormone)
The body's bonding and trust hormone. As an injection it is FDA-approved (Pitocin) to start or strengthen labour contractions. As a nasal spray it has been studied for social cognition, anxiety and intimacy, with mixed results, and that use is not approved. In the brain it acts on social-threat and bonding circuits.
4
Gene variants
40+
Studies
Kisspeptin-10
also studied for sexual desireEmerging EvidenceKisspeptin-10 (Metastin fragment)
A signalling peptide at the top of the reproductive hormone axis. Kisspeptin-10 stimulates the hypothalamus to release GnRH, which in turn drives LH and FSH and then testosterone or oestrogen. It is a research tool in fertility and sexual-behaviour studies, and it is not an approved medicine.
4
Gene variants
30+
Studies
Access
Access and legal status
PT-141: Prescription (Vyleesi, for low sexual desire in premenopausal women). Decisions about any prescription medicine belong to a prescriber. We don't link to any seller, and nothing on this page is a recommendation to obtain or use it.
Your DNA and PT-141: see which of the variants studied alongside it you carry, and what that research does and does not show. Read my DNA, $99 →
Educational information only, not medical advice. Most peptides are not FDA-approved. Do not start, stop or change any medication or peptide because of this page; talk to a licensed clinician.
Worth knowing about PT-141
Interactions and situations where there is a specific reason to be careful. Where the honest answer is that nobody has studied something, it says so and says what that leaves open.
- It raises blood pressure briefly
- A transient rise in blood pressure with a fall in heart rate is the known effect. It is the reason the nasal version was abandoned: reaching useful levels through the nose needed doses where the cardiovascular effect was not manageable. It is not recommended in uncontrolled high blood pressure or known cardiovascular disease.
- Nausea is common and darkening of the skin can happen
- Nausea is the most frequent complaint in the trials. Because it acts on melanocortin receptors, the family involved in pigmentation, focal darkening of skin can occur, more often with repeated dosing.
- The effect size is genuinely debated
- Approval is not the same as a large benefit. The published critique below argues the improvement on the trial questionnaires was small and the questionnaires themselves poorly validated for this condition.
The evidence behind PT-141
This is one of the few approved medicines in the catalogue, so the evidence is real. What makes it interesting is that the argument did not end at approval: a 2024 analysis in the Journal of Sex Research went back to the trials and argued the questionnaires used to measure success have questionable validity, and that the actual effect was small. Both things are true at once, and a page that gives you only the approval is telling you half of it.
The literature, counted
Counted in PubMed on 3 August 2026 for bremelanotide OR PT-141. Every figure links to the search that produced it, so you can re-run it. “Tagged human” is not the same as a human trial: that tag also covers work on human cells and reviews discussing people, which is why the trial count is given separately.
Studied in people
1 of 1The only kind that directly answers whether it works in humans.Reviews
2 of 3Papers that gather other studies rather than run new ones.Journal of Sex Research · 2024
ReviewSmall Effects, Questionable Outcomes: Bremelanotide for Hypoactive Sexual Desire Disorder
Spielmans GI, Ellefson E
Re-examined the RECONNECT trials and concluded the questionnaires used to judge success have questionable validity for this condition, and that the categorical response outcomes had no validity evidence at all. The honest counterweight to the approval, and it is almost never cited alongside it.
Small Effects, Questionable Outcomes: Bremelanotide for Hypoactive Sexual Desire Disorder: source for PT-141 (opens in a new tab)Read the reviewCNS Spectrums · 2022
ReviewThe neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women
Mayer D, Lynch SE
Explains why this works differently from the erectile-dysfunction drugs. Those act on blood flow; this acts on melanocortin receptors in the brain, upstream of arousal rather than downstream of it.
The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women: source for PT-141 (opens in a new tab)Read the review
Every source behind this page52 more
- An evaluation of bremelanotide injection for the treatment of hypoactive sexual desire disorderSimon JA, Kingsberg SA · Expert Opinion on Pharmacotherapy · 2023Review
- Bremelanotide: New Drug Approved for Treating Hypoactive Sexual Desire DisorderDhillon S, Keam SJ · Annals of Pharmacotherapy · 2020Official
Everything we cite for PT-141, including preclinical work and early research. Each link goes to the source itself, so you can judge it rather than take our word for it.
Last updated · literature counts verified against PubMed on
Frequently Asked Questions
What is PT-141 approved for?
PT-141 (bremelanotide) is FDA-approved as Vyleesi for acquired, generalised hypoactive sexual desire disorder in premenopausal women. It has been studied in men but is not approved for them. It acts on the brain's melanocortin system rather than on blood flow.
How is PT-141 different from Viagra?
Viagra and Cialis (PDE5 inhibitors) improve blood flow to enable an erection. PT-141 acts upstream, in the brain, on the signals behind desire. That is why it was developed for low desire rather than for erectile function.
Do genes affect PT-141 response?
No study has tested whether any genotype changes response to bremelanotide. MC4R builds one of the receptors it acts on, and its common variants have been studied for appetite and body weight rather than for drug response. A DNA report can show which versions you carry and what that research does and does not show.
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Your DNA and PT-141
What the research says about your variants.
The report
Which PT-141 variants do you carry?
Your report reads the DNA file you already have against the published research on 31 peptides, marker by marker, and says what that research does and does not show.
Read my DNA, $99