PT-141

In simple words

PT-141 (bremelanotide) is a ring-shaped peptide approved in the U.S. as a medicine for women with low sexual desire. It works through the brain rather than the blood vessels, and it is being studied as a way to enhance desire.

What this molecule is

Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OH — cyclic heptapeptide (7 aa), an α-MSH analog. Cyclized via an Asp-Lys lactam bridge. FDA-approved 2019.

Why it is studied

FDA-approved (Vyleesi, 2019) — the first-in-class melanocortin agonist for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. RECONNECT Phase III (n=1247): significant ↑sexual desire + ↓distress. Central (not vascular) mechanism — a difference from PDE5 inhibitors.

How it works

MC3R and MC4R agonist in the hypothalamus → activates sexual arousal and motivation centers → ↑dopaminergic transmission in the limbic system → ↑libido. Does not directly affect vascular tone → ↓cardiovascular risks vs PDE5 inhibitors. Nasal spray: rapid onset in 15-60 min.

Doses used in studies

Approved form (Vyleesi, FDA): 1.75 mg subcutaneously 45 min before the anticipated effect, no more than once every 24 h and no more than 8 doses per month. The nasal form was studied in early trials at doses of 7–20 mg; its development was discontinued.

Combined with in studies

• Oxytocin nasal — emotional closeness + PT-141 = deep synergy
• Kisspeptin — central arousal
• Drugs that raise blood pressure — NOT compatible

Level of evidence

Level A Human clinical trials. There are randomized controlled trials (RCTs), or the compound has been approved by a regulatory agency. The most reliable level. FDA-approved 2019. Phase III in Obstet Gynecol.

Important to know

⚠️ Nausea 40%, flushing 20%, headache 11%. Prescribed only to premenopausal women with HSDD. Prescription drug.

Studies in PubMed

1. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. (Obstet Gynecol, 2019)
2. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder. (Obstet Gynecol, 2019)
3. Prespecified and Integrated Subgroup Analyses from the RECONNECT Phase 3 Studies of Bremelanotide. (J Womens Health (Larchmt), 2022)
4. Safety Profile of Bremelanotide Across the Clinical Development Program. (J Womens Health (Larchmt), 2022)
5. An evaluation of bremelanotide injection for the treatment of hypoactive sexual desire disorder. (Expert Opin Pharmacother, 2023)