PT-141 (bremelanotide), explained

It works on desire, not blood flow

PT-141 is the research name for bremelanotide, a melanocortin receptor agonist. Instead of acting on blood flow like tadalafil or sildenafil, it acts on pathways in the brain involved in sexual desire.

What it's approved for

Bremelanotide is the active ingredient in Vyleesi, which the FDA approved for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD): low sexual desire that causes real distress and isn't caused by another medical or mental health condition, relationship problems, or a medication.

Its label is clear that it isn't approved for women after menopause or for men. Those uses are off-label.

What the trials found

Vyleesi was approved based on two phase 3 trials with 1,267 premenopausal women, average age 39. Over 24 weeks, women taking bremelanotide reported significantly greater increases in sexual desire than women taking placebo.

Those trials studied Vyleesi: an injection, on its own, in that group of women. Compounded PT-141 is not FDA-approved, and forms that dissolve in the mouth or combine it with other ingredients weren't part of those studies.

How the approved product is used

Vyleesi is a small injection under the skin, taken as needed at least 45 minutes before sex. Its label says not to take more than one dose in 24 hours, and not more than 8 doses a month. Your clinician and pharmacy label set the directions for your own treatment.

Side effects, and who it isn't for

Nausea is common: in the trials, 40% of women had it, and it's often worst after the first doses. Flushing, headache and injection-site reactions are also common. Blood pressure rises briefly after each dose and usually settles within 12 hours, and frequent use can cause darker patches of skin.

It isn't for anyone with uncontrolled high blood pressure or known heart disease. Your clinician will go through your history before prescribing.