You are 34, on the pill, and your gynecologist has mentioned Vyleesi, the prescription bremelanotide autoinjector for low sexual desire that causes distress. Online, the same molecule shows up as PT-141 on research sites. Before you think about it further, you want to know something practical: did it work for women like you in the trials, and how big was the change?
The short version from the company-run data: in a pooled look at 1,202 women from the two phase 3 trials, desire scores improved more on bremelanotide than on placebo across age, weight and body mass index groups, with few exceptions. For women using hormonal birth control, the drug lowered distress about low desire, but the gain in desire itself was only a numerical edge that did not reach statistical significance. And across all women, the average change was modest.
What the subgroup analysis looked at
The RECONNECT program ran two identical 24-week placebo-controlled trials in premenopausal women with acquired, generalized hypoactive sexual desire disorder. In 2022, James Simon and colleagues reported prespecified subgroup results in the Journal of Women’s Health. They split women by age, weight, body mass index and testosterone level in the blood, and also checked hormonal contraceptive use, whether low arousal came along with low desire, and how long the problem had lasted.
Bremelanotide beat placebo on both main measures, a desire score and a distress score, in almost every age, weight and testosterone group, regardless of low arousal or how long low desire had lasted. The one clear split was birth control. Women not on hormonal contraceptives had a statistically significant rise in desire. Women on them had a smaller-looking edge that could have been chance, although their distress still fell significantly.
That detail matters more than it might seem. The Vyleesi label says women in heterosexual relationships had to use effective contraception during the trials, and it advises contraception while taking the drug. Subgroups are smaller than the full trial, so a non-significant result can reflect too few women rather than no effect. The paper does not settle the question either way. Several authors worked for Palatin Technologies or AMAG Pharmaceuticals, the companies behind the drug.
How big the average change was
The FDA label gives the numbers behind “it worked.” On a desire scale that runs from 1.2 to 6.0, average scores rose about 0.5 to 0.6 points on bremelanotide versus 0.2 on placebo. Distress fell about 0.7 points on a 0 to 4 scale versus 0.4 on placebo. There was no significant difference in the number of satisfying sexual events. The label also notes that far more women stopped early on the drug: 40 percent versus 13 percent in one trial and 39 percent versus 25 percent in the other.
To judge what counts as a change women actually notice, the developers had earlier run a phase 2b dose-finding trial in premenopausal women. Its main report, published in 2016 with efficacy data from 327 women, found the two higher strengths added about 0.7 satisfying sexual events a month versus 0.2 on placebo, with nausea, flushing and headache as the common side effects. A 2019 follow-up by Stanley Althof and colleagues used that trial to set responder thresholds, the smallest change patients themselves rate as meaningful. At the strength later approved, significantly more women than on placebo crossed those thresholds on all seven measures studied. The label’s phase 3 responder cutoff for desire was a rise of at least 1.2 points, about twice the average gain seen on the drug.
Questions to bring to your appointment
If you use hormonal birth control, ask whether the subgroup result changes your expectations, and whether other causes of low desire, including medicines, mood, sleep, pain or relationship strain, have been looked at first. Ask how you will judge whether it is helping: the label says to stop after eight weeks if symptoms have not improved. Check blood pressure and nausea plans before the first use. Vyleesi is not indicated after menopause or in men.
None of these studies tested a research-grade PT-141 vial. The trials used a regulated product with prescriber screening, and the results do not transfer to a powder sold for laboratory use. Not medical advice.
Sources
- Simon JA et al. Prespecified and integrated subgroup analyses from the RECONNECT phase 3 studies of bremelanotide. J Womens Health, 2022 (PubMed)
- Clayton AH et al. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Womens Health, 2016 (PubMed)
- Althof S et al. Responder analyses from a phase 2b dose-ranging study of bremelanotide. J Sex Med, 2019 (PubMed)
- DailyMed: Vyleesi (bremelanotide) prescribing information
- ClinicalTrials.gov: bremelanotide phase 2b dose-finding trial in premenopausal women (NCT01382719)
Related reading
- Did Vyleesi trial volunteers want to keep going?
- PT-141 research listings do not inherit the Vyleesi evidence file
- Vyleesi desire shots bring nausea and blood pressure tradeoffs
By The Everyday Brief. AI-assisted drafting with automated source and editorial checks. Sources fetched 2026-10-23 PT. Not medical advice.