PT-141
FDA-approved
Also known as: Bremelanotide, Vyleesi
PT-141 (bremelanotide) is a lab-made, ring-shaped peptide of seven amino acids, given by injection under the skin. It is modeled on alpha-MSH, a natural hormone, and switches on melanocortin receptors in the brain and skin. As Vyleesi, it is approved for one form of low sexual desire in premenopausal women.
Approved for treating acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women (as Vyleesi). This means low sexual desire that causes marked distress or interpersonal difficulty. It must not be caused by another medical or psychiatric condition, relationship problems, or a medicine or drug. It is not approved for HSDD after menopause, for men, or to enhance sexual performance.
How it works
- It switches on several melanocortin receptors, a family that responds to hormones such as alpha-MSH. At treatment doses, the MC1 and MC4 receptors matter most.
- Its label states that how it improves sexual desire in women is unknown.
- Animal studies suggest it acts on MC4 receptors in a part of the hypothalamus tied to sexual behavior. There it may increase release of dopamine, a brain signal linked to desire.
- In mice, a different drug that is highly selective for MC4 receptors strengthened erections, but not in mice bred without the receptor. Those mice also mated less.
- MC1 receptors sit on the skin's pigment cells, which explains the darker skin patches some people develop.
Evidence
Low sexual desire (HSDD) in premenopausal women
Two identical 24-week phase 3 trials (RECONNECT) randomized 1,267 premenopausal women with HSDD to the drug or placebo. Compared with placebo, women on it reported more sexual desire and less distress about low desire. The average gains were small: desire scores rose 0.35 points and distress scores fell 0.33 points more than on placebo. Nausea, flushing and headache were more common on the drug.
Caveats
- Nausea affected 40% of women in the phase 3 trials, versus about 1% on placebo, and led 8% to stop. For most, it eased by the second dose.
- Flushing, injection-site reactions and headache were also common.
- It briefly raises blood pressure and slows heart rate after each dose. Its label lists uncontrolled high blood pressure and known heart or blood vessel disease as contraindications. It is not recommended for people at high risk of heart disease.
- Patches of darker skin on the face, gums or breasts appeared in 1% of trial patients. They were far more common with daily use, more likely in people with darker skin, and did not always fade after stopping.
- It can slow stomach emptying, which may change how pills taken by mouth are absorbed. It may significantly lower blood levels of naltrexone taken by mouth. Its label advises against that combination when naltrexone treats alcohol or opioid addiction.
References
This page is for education only. It is not medical advice. Decisions about any treatment belong with a physician who knows your history.