PT-141 is the development name of bremelanotide, which the FDA approved in 2019 as Vyleesi. Unlike most compounds sold under peptide code names, it has a label and two large phase 3 trials, and those trials were run in women. That makes "PT-141 for women" a question with a measured answer — but a narrower one than most pages imply, because the approval covers one group of women and one outcome.
What the trials recorded as side effects is on our PT-141 side effects page, and what the label states about the dose is on our PT-141 dosage page. Nothing here is a recommendation; low sexual desire has many causes, and the label itself requires ruling them out first.
Who it is approved for — and who it is not
The label (13 November 2025, read through openFDA on 15 October 2026) is specific. Vyleesi is indicated for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD): low desire that causes marked distress or difficulty between partners, that developed after a period without problems, that happens regardless of situation or partner, and that is not due to another medical or psychiatric condition, relationship problems, or a medicine.
Its "Limitations of Use" say it is not indicated for postmenopausal women, for men, or to enhance sexual performance. It is contraindicated in uncontrolled high blood pressure and known cardiovascular disease.
The two trials, read from the label
Both RECONNECT trials (NCT02333071 and NCT02338960) were identical, double-blind and placebo-controlled for 24 weeks, followed by a 52-week open-label extension. 1,267 women were randomised — 635 to bremelanotide 1.75 mg, 632 to placebo — injected as needed about 45 minutes before expected sexual activity, no more than once a day. Mean age was 39 (range 19–56); most had been with the same partner for about 12 years and had low desire for about four. Across both trials the median number of injections in 24 weeks was 10 — most women used it two or three times a month.
Two co-primary outcomes, both self-rated over the previous four weeks:
| Outcome | Scale | Study 1: drug vs placebo | Study 2: drug vs placebo | Placebo-adjusted (published) |
|---|---|---|---|---|
| Desire (FSFI desire domain) | 1.2 to 6.0, higher = more desire | +0.5 vs +0.2 | +0.6 vs +0.2 | +0.30 and +0.42; pooled +0.35 |
| Distress about low desire (FSDS-DAO item 13) | 0 to 4, higher = more bothered | −0.7 vs −0.4 | −0.7 vs −0.4 | −0.37 and −0.29; pooled −0.33 |
Both differences were statistically significant in both trials (label; Kingsberg et al., Obstet Gynecol 2019, PMID 31599840). Baseline desire averaged about 2.0 on the 1.2–6.0 scale.
How large is that change?
Two numbers from the same label help read it.
The responder threshold. To judge whether a change was meaningful to women, the label's supplementary analyses defined a responder as a woman whose desire score rose by at least 1.2 points (and whose distress score fell by at least 1). The average placebo-adjusted change of 0.35 is 29% of that threshold — our arithmetic. Averages hide individuals: some women crossed it and many did not, which is why the label also shows responder figures rather than relying on the mean.
Who stayed in. More women on the drug than on placebo stopped the double-blind phase early — 40% vs 13% in Study 1 and 39% vs 25% in Study 2. The label's responder figures count those who stopped as non-responders, which is the conservative reading. A trial in which four in ten women on the active drug did not finish is a trial whose average describes a selected group by the end.
In the open-label extension (no placebo; 684 entered, 272 completed), desire scores at the end were 1.25–1.30 points above the original baseline in women who had been on the drug throughout (Simon et al. 2019, PMID 31599847). Without a control group and with most women gone, that figure shows what happened to those who stayed, not what the drug did.
Timing: what "how long does it take to work" has as an answer
The label states three things and no more:
- It is injected at least 45 minutes before anticipated sexual activity.
- "The duration of efficacy after each dose is unknown and the optimal window for VYLEESI administration has not been fully characterized."
- It should be stopped after eight weeks if a woman reports no improvement.
No trial measured desire hour by hour after a dose. Claims of effects lasting a set number of hours do not come from the label.
Nausea and the other trade-offs women in the trials faced
40% of women reported nausea, 13% needed anti-nausea medicine and 8% stopped because of it; the label says it improved for most with the second dose. Blood pressure rises and heart rate falls transiently after each dose, and darkening of skin patches was reported in 1% at up to eight doses a month but in 38% after eight daily doses in a separate study. The label advises against more than eight doses a month. All of this is set out with the label's figures on our side effects page.
Who was never tested
- Postmenopausal women. Excluded from the phase 3 trials; the label excludes them. A PubMed search on 15 October 2026 for bremelanotide and postmenopausal returned seven records, all reviews or discussions of treatment options — no efficacy trial.
- Women whose low desire has another cause — depression, a medicine such as an antidepressant, a relationship problem. They were excluded by design.
- Women who are pregnant or breastfeeding. The label advises contraception and says use in pregnancy is not recommended. A study measuring bremelanotide in breast milk finished in November 2025 and has not posted results; our peptides and breastfeeding page tracks it.
- Daily use. The trials tested as-needed use; daily dosing appeared only in the pigmentation study.
Two more registrations add to the record without changing it: a 193-woman bridging trial for the Korean market by Kwang Dong Pharmaceutical (NCT04943068, completed May 2023, no results posted) and a 40-woman brain-imaging study at Imperial College London (NCT04179734), which measured brain responses rather than desire in daily life.
Research PT-141 is not Vyleesi
The trial results above belong to a sterile 1.75 mg autoinjector made under an approved application. Vials sold online as "PT-141" share the molecule's name but not its label, its manufacturing or any test of content. What that difference means in practice is on our PT-141 dosage page. For the other hormone-axis peptide studied in women — for fertility rather than desire — see our kisspeptin for women page, and for how bremelanotide's effect size compares with other approved peptides, our peptides before and after page.
Sources and dates
Read 15 October 2026: Vyleesi prescribing information via openFDA (effective 13 November 2025; sections 1, 2, 4, 5, 8 and 14 including Tables 2 and 3 and the supplementary responder analyses); abstracts of PMIDs 31599840 and 31599847; PubMed search for bremelanotide and postmenopausal (seven records, all reviews); ClinicalTrials.gov records NCT02333071, NCT02338960, NCT04943068, NCT04179734 and NCT06867835.