Bremelanotide (Vyleesi): What It Is, How It Works, and What the Research Shows

At a glance: Bremelanotide (brand name Vyleesi, also known as PT-141) is an FDA-approved prescription injection for hypoactive sexual desire disorder (HSDD) in premenopausal women. It acts on the brain rather than on blood flow. In trials it produced small but real improvements in desire, and about 4 in 10 users had nausea. It is not approved for men or postmenopausal women.

What is bremelanotide?

Bremelanotide is a synthetic peptide that activates melanocortin receptors, part of a brain signaling system involved in appetite, skin pigment and sexual motivation. It grew out of research on melanotan II, a tanning peptide whose testers unexpectedly reported increased sexual arousal; bremelanotide is a closely related compound developed specifically for sexual function.

It was developed by Palatin Technologies and approved by the FDA in June 2019 as Vyleesi. Palatin sold the product to Cosette Pharmaceuticals in late 2023.

How does bremelanotide work?

• Acts in the brain: it activates melanocortin receptors, especially MC4, in brain areas linked to sexual desire and motivation
• Not a blood-flow drug: unlike Viagra-type medicines, it does not work by increasing genital blood flow
• Used as needed: it is taken before anticipated sexual activity rather than every day, unlike flibanserin (Addyi), the other approved HSDD drug, which is a daily pill

The FDA label notes that exactly how it improves desire in HSDD is not fully understood.

What the research shows

Bremelanotide was approved based on two large phase 3 trials (the RECONNECT studies) in premenopausal women with long-standing HSDD.

The improvements were modest on average; some women benefit noticeably and others little. The open-label extension supported longer-term safety.

Why it gets attention

• One of only two FDA-approved drugs for low sexual desire in women
• As-needed use instead of a daily pill
• Brain-based mechanism, addressing desire rather than physical arousal
• Off-label and gray-market interest as "PT-141", including among men, for whom it is not approved

How it is used

Vyleesi comes in a single-use autoinjector pen, injected under the skin of the abdomen or thigh at least 45 minutes before anticipated sexual activity. The label limits use to no more than one dose in 24 hours and no more than eight doses per month. Doctors typically recommend stopping if there is no improvement after about 8 weeks. Use is decided with a prescriber; this page does not provide dosing guidance.

What about side effects?

From the trials and FDA label:

• Nausea: about 40% of users, often worst with the first doses; about 13% in trials needed anti-nausea medicine, and some stopped treatment because of it
• Flushing: about 20% (warmth and redness of the face and neck)
• Injection-site reactions: about 13%
• Headache: about 11%; vomiting about 5%
• Blood pressure: a temporary rise in blood pressure and drop in heart rate after each dose
• Skin darkening: patches of darker skin on the face, gums or breasts, more common with frequent use and in people with darker skin; it may not fully fade

It should not be used by people with uncontrolled high blood pressure or heart disease. It may harm an unborn baby, so effective birth control is advised. It can reduce levels of oral naltrexone, so the two are generally not combined.

Regulatory status

• FDA-approved (June 2019) as Vyleesi for acquired, generalized HSDD in premenopausal women whose low desire is distressing and not caused by another medical, mental health or relationship problem, or by medication.
• Not approved for men, postmenopausal women, or to enhance sexual performance.
• Prescription only. "PT-141" sold online as a research peptide or nasal spray is not the approved product and has no quality guarantees.

How it compares

The bottom line

Bremelanotide is a legitimate, FDA-approved treatment with real trial evidence, offering an as-needed option for premenopausal women distressed by low sexual desire. Its benefits are modest on average and nausea is common, so it suits some women better than others. It is not approved for men, and online "PT-141" is not the regulated product. Anyone interested should talk with a clinician, ideally one experienced in sexual health.

Frequently asked questions

What is Bremelanotide?

A peptide that acts on melanocortin receptors in the brain. Approved by the FDA in 2019 for premenopausal women with hypoactive sexual desire disorder.

How is Bremelanotide taken?

As-needed subcutaneous autoinjector.

Is Bremelanotide FDA approved?

FDA-approved (prescription).

What has research shown about Bremelanotide?

• Sexual desire and related distress in clinical trials.
• Side effects such as nausea and temporary blood pressure increases.

What side effects have been reported?

• Nausea, which can be severe
• Flushing
• Headache
• Fatigue
• Dizziness
• Injection site reactions

Serious or less common risks are listed in the Side Effects section above.

What is still unknown about its safety?

Side effects that are rare, or that only appear after many years of use, are still being tracked through post-marketing surveillance. Talk to a prescriber about your own risk.

References

1. Mayo Clinic: Bremelanotide (subcutaneous route) description, precautions and side effects. View source
2. Oregon Drug Use Review: bremelanotide drug evaluation (phase 3 trial results and label safety data), 2020. View source
3. Simon JA, et al. Long-term safety and efficacy of bremelanotide for hypoactive sexual desire disorder. Obstetrics and Gynecology. 2019. View source
4. Contemporary OB/GYN: Sexual dysfunction treatment approved by FDA (2019). View source
5. Palatin: completes sale of Vyleesi to Cosette Pharmaceuticals. View source