PT-141 is the research name for bremelanotide. It is the one peptide on this site with an FDA approval for sexual desire. That approval is narrow, and the benefit the trials measured was modest.
Here is what the approval covers, what the trials found, and what they did not test. For its status and sellers, see the PT-141 guide and the sexual health goal page.
What the FDA approved
The FDA approved bremelanotide as Vyleesi on June 21, 2019. It is an injection under the skin, taken as needed before sex.
The approval covers acquired, generalized hypoactive sexual desire disorder in premenopausal women. That means low desire that causes distress, that was not always there, and that is not tied to one partner or situation.
It does not cover men. It does not cover women after menopause. It does not cover erectile dysfunction.
What the two phase 3 trials found
The RECONNECT trials enrolled 1,267 premenopausal women with low desire [1]. Half took 1.75 mg as needed for 24 weeks. Half took placebo.
Both trials met both main goals. Desire scores rose 0.35 points more than on placebo. Distress about low desire fell 0.33 points more [1].
Those numbers are small. The desire score runs from 1.2 to 6, so the average gain was a fraction of one step. You cannot tell from an average whether your own change would be large enough to notice.
An earlier dose-finding trial measured something more concrete. In 327 premenopausal women, the two higher doses added 0.7 satisfying sexual events a month, against 0.2 on placebo [2].
The side effects
Nausea is the one to plan for. Across the phase 3 trials, 40.0% of women on bremelanotide had nausea, against 1.3% on placebo [3].
Flushing affected 20.3% and headache 11.3%. Nausea was the most common reason women stopped [3].
Two more findings matter if you have heart disease or dose often. Blood pressure rose slightly and briefly in monitoring studies. Dark skin patches were rare at label dosing, but appeared in over a third of people given up to 16 daily doses in a row [3].
The safety review’s authors advise caution in people at risk of heart disease. They also say blood pressure should be well controlled during treatment [3].
What happened over a year
An open-label extension followed 684 women for another 52 weeks, with no placebo group [4]. Only 272 finished it.
Nausea was reported by 40.4% of women in the extension. The authors found no new safety signals [4].
What about men?
PT-141 was first tested in men with erectile dysfunction. A 2004 study of an intranasal form found erections better than placebo at doses above 7 mg [5].
Those were single doses measured in a lab. No trial has established PT-141 for erectile dysfunction, and it is not approved for it.
What this means for you
If you are a premenopausal woman with distressing low desire, bremelanotide has two trials behind it. Expect a modest average effect, and a real chance of nausea.
An online seller may dispense compounded PT-141 rather than Vyleesi. A compounded version was not what these trials tested. Ask your prescriber which one you would get, and why. The reviews of Care Bare Rx and Strut Health say what each seller offers for sexual health.