Bremelanotide

• Acquired, generalized hypoactive sexual desire disorder (low sexual desire) in premenopausal women

Bremelanotide (Vyleesi) is an FDA-approved peptide injection for low sexual desire in women who have not gone through menopause. It is better known by its research name, PT-141. Unlike daily pills, it is used only as needed, injected under the skin at least 45 minutes before anticipated sexual activity. FDA approved it in June 2019 for acquired, generalized hypoactive sexual desire disorder (HSDD).

What Hypoactive Sexual Desire Disorder Is

HSDD means a persistent lack of sexual desire that causes distress and is not better explained by another medical or psychiatric condition, relationship problems, or the effects of a medication or substance. "Acquired" means desire was normal before, and "generalized" means it is low regardless of partner, situation or type of activity.

Low desire is common and has many causes, so a careful evaluation comes first. Depression, anxiety, thyroid disease, fatigue, pain with sex, antidepressants and other medicines, and the hormone shifts of perimenopause can all play a role. Treating those causes is often more effective than any medication.

How Bremelanotide Works

Bremelanotide activates melanocortin receptors, mainly the MC4 receptor, in areas of the brain involved in sexual motivation. It is a synthetic peptide related to alpha-melanocyte-stimulating hormone. Exactly how it raises desire is not fully understood, but it acts in the brain rather than by increasing blood flow, which is how erectile dysfunction pills work.

It was developed from melanotan II, a tanning peptide. Melanotan II is not approved, is sold illegally online, and has been linked to new and changing moles. Bremelanotide is a different, FDA-regulated product, and the two should not be confused.

What the Clinical Trials Showed

Approval was based on two 24-week randomized, placebo-controlled trials in about 1,200 premenopausal women with HSDD, called RECONNECT. Compared with placebo, women using bremelanotide reported modest increases in sexual desire and decreases in distress about low desire. The number of satisfying sexual events did not differ meaningfully from placebo.

The benefit is modest. About a quarter of women on bremelanotide had a meaningful rise in desire, compared with about 17 percent on placebo, as described in the Vyleesi prescribing information. It is a reasonable option for some women, not a cure.

Who It Is Not Approved For

Bremelanotide is not approved for postmenopausal women or for men, and it is not meant to enhance sexual performance. Studies of PT-141 for erectile dysfunction were not pursued to approval. Compounded "PT-141" and nasal sprays sold online are not the FDA-approved product.

Dosing and How to Use It

The dose is one 1.75 mg autoinjector into the abdomen or thigh, at least 45 minutes before anticipated sexual activity. The label limits use to one dose in 24 hours and eight doses per month. If desire and distress have not improved after 8 weeks, treatment should be stopped. Full instructions are in the Vyleesi label on DailyMed.

Side Effects and Safety

Nausea is the most common side effect, reported by about 40 percent of women in trials, most often with the first doses. About 13 percent needed anti-nausea medicine. Flushing, injection site reactions and headache are also common.

Blood Pressure

Each dose temporarily raises blood pressure and lowers heart rate, with levels usually returning to baseline within about 12 hours. For that reason, bremelanotide should not be used by anyone with uncontrolled high blood pressure or known heart disease. We check blood pressure before prescribing it.

Skin Darkening

About 1 percent of women developed darker patches on the face, gums or breasts, and the rate was higher with more frequent dosing. In some women the darkening had not resolved after stopping.

Alternatives to Discuss

The only other FDA-approved medicine for HSDD in premenopausal women is flibanserin (Addyi), a daily pill. Counseling, sex therapy, addressing pain or vaginal dryness, and changing a medication that dampens desire can all help. For women in midlife, our women's health resources explain how hormones affect desire.

What to Expect at an Evaluation for Low Desire

A visit about low sexual desire is a medical appointment like any other, and it is confidential. Expect questions about when the change began, whether it is constant or depends on the situation, and how much it bothers you. Desire that is lower than a partner's is not, by itself, a disorder; the diagnosis depends on persistent change and personal distress.

Medications and Health Conditions

We review every medicine you take. Antidepressants in the SSRI and SNRI groups, some blood pressure medicines, hormonal birth control and opioids can all lower desire, and an adjustment sometimes solves the problem. We also screen for depression and anxiety, thyroid disease, anemia, diabetes and sleep problems, which are common and treatable. Pain with intercourse, vaginal dryness or pelvic floor problems can make desire fade over time and need their own treatment.

Relationship and Life Factors

Stress, exhaustion, caregiving, conflict and body image changes affect desire for many women. Counseling or sex therapy, alone or as a couple, has good evidence and can be combined with medication.

Deciding on Medication

If HSDD remains the best explanation, we discuss bremelanotide and flibanserin, including how often each is used, their side effects, cost and insurance coverage. A blood pressure check is part of the decision for bremelanotide.

Getting Care in St. Petersburg

Low desire is a medical concern worth raising, and our internists approach it without judgment. We review medications, check labs where useful through our in-office lab, and talk through treatment options, including FDA-approved peptides. To start the conversation, schedule a visit.