PT-141 (Bremelanotide): The FDA-Approved Peptide for Sexual Dysfunction

Written by Adam Maggio | Medically reviewed by Dr. Sarah Chen, PharmD, BCPS

PT-141 (bremelanotide) is FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. It works centrally via melanocortin receptors to increase sexual desire. Dose: 1.75 mg subcutaneously 45 minutes before sexual activity. Also used off-label in men for erectile dysfunction.

From Research Peptide to FDA-Approved Drug

PT-141 (bremelanotide) began as a research derivative of Melanotan II and ultimately became the first FDA-approved treatment for hypoactive sexual desire disorder (HSDD) in premenopausal women, marketed as Vyleesi. Its journey from university research lab to regulatory approval illustrates the potential of peptide-based approaches to conditions that have historically been difficult to treat pharmacologically.

Mechanism of Action

Unlike PDE5 inhibitors (Viagra, Cialis), which work peripherally by increasing blood flow to genital tissue, PT-141 works centrally — in the brain. It is a melanocortin receptor agonist that activates MC4R receptors in the hypothalamus and limbic system, the brain regions responsible for sexual motivation and arousal. This central mechanism means PT-141 addresses the neurological component of sexual desire rather than just the vascular component.

FDA Approval: Vyleesi

The FDA approved bremelanotide (Vyleesi) in June 2019 for the treatment of acquired, generalized HSDD in premenopausal women. The approval was based on two Phase 3 clinical trials (RECONNECT studies) that demonstrated statistically significant improvements in sexual desire and reductions in distress related to low sexual desire compared to placebo. Vyleesi is administered as a 1.75 mg subcutaneous injection using an autoinjector pen, taken approximately 45 minutes before anticipated sexual activity.

Off-Label Use in Men

While PT-141 is only FDA-approved for women, it is widely used off-label in men for erectile dysfunction and low libido, particularly in cases where PDE5 inhibitors are ineffective or contraindicated. Men typically use doses of 1–2 mg subcutaneously 1–2 hours before sexual activity.

Side Effects

The most common side effects are nausea (40% of patients in clinical trials), flushing, and transient increases in blood pressure. PT-141 is contraindicated in patients with cardiovascular disease or uncontrolled hypertension. Nausea can be managed with antiemetics taken 30 minutes before administration.