Bremelanotide (PT-141): what is it meant to do?

What problem is the medicine intended to address?

Desire varies between people and across life. Low desire is not automatically an illness; what matters to someone, and whether it causes distress, are part of the conversation. In the United States, Vyleesi is indicated for acquired, generalised hypoactive sexual desire disorder in premenopausal women. “Acquired” means the difficulty began after a period without it; “generalised” means it occurs across situations, partners or kinds of stimulation. The label specifies that it must not be due to a medical or psychiatric condition, relationship problems, or another medicine or drug. A clinician can help explore those possibilities without assuming a single cause.12

How is it supposed to work?

Bremelanotide activates receptors in the melanocortin family, signalling switches found in different parts of the body. The exact way it improves desire and related distress is not known. A receptor response is not the same as an immediate guarantee of desire, arousal or satisfying sex. The prescription medicine is not indicated to enhance sexual performance, or to treat this disorder in men or postmenopausal women under the US label.1

What did the studies show?

Two 24-week placebo-controlled trials in premenopausal women with the defined condition found greater average improvement in questionnaire scores for desire and related distress with bremelanotide. The difference in the number of satisfying sexual events was not statistically significant. Nausea was common. More people stopped the blinded treatment early in the medicine groups, which matters when interpreting results. See what the RECONNECT trials actually measured for the numbers and limits.12

Is PT-141 the same as Melanotan II?

PT-141 is another name for bremelanotide. It is a different substance from Melanotan II, although both interact with melanocortin receptors. Small, short Melanotan II studies measured erections in men; the Vyleesi trials asked different questions in a different population. Neither result can be transferred wholesale to the other substance. Read the Melanotan II and sexual-response comparison.124

What should people know about side effects and other medicines?

In the pooled controlled trials, nausea was reported by about 40% receiving Vyleesi and 1% receiving placebo; flushing and headache were also more frequent. The US label warns of temporary rises in blood pressure and decreases in heart rate, and says Vyleesi is contraindicated in people with uncontrolled high blood pressure or known cardiovascular disease. Skin darkening can sometimes persist. Vyleesi can slow stomach emptying and affect absorption of medicines taken by mouth. Severe kidney impairment can increase exposure and the chance of adverse reactions, so it needs specific prescriber review; the label recommends caution in severe liver impairment, which has not been studied. The label advises avoiding it with oral naltrexone products used for alcohol or opioid addiction, because reduced naltrexone exposure could have serious consequences. Discuss all medicines and any kidney or liver condition with a prescriber or pharmacist rather than changing them independently. Learn more about interactions and side effects.13

The US Vyleesi label says not to use more than one dose in 24 hours and does not recommend more than eight doses per month; more frequent use can increase safety risks. It also advises discontinuing Vyleesi if symptoms have not improved after eight weeks. These are limits for this specific approved product; discuss the treatment plan and any concerns with the prescriber.1

What about pregnancy and storage?

The US label advises effective contraception during treatment and stopping Vyleesi if pregnancy is suspected. Anyone pregnant, planning pregnancy or breastfeeding should discuss their circumstances with a clinician. The US label says to store Vyleesi at or below 25°C (77°F), protect it from light and not freeze it. That instruction belongs to Vyleesi: a differently formulated product may have different requirements. For an uncertain excursion, ask a pharmacist or the product manufacturer; appearance does not prove suitability. See storage guidance.13

Does an online vial labelled PT-141 equal Vyleesi?

No. The ingredient name alone does not establish the identity, concentration, sterility, formulation or legal status of a particular product. A compounded or online preparation is not automatically the FDA-approved Vyleesi product. Rules and available products vary by country. For what a laboratory document can and cannot show, see how to read a certificate of analysis.1