PT-141 (Bremelanotide)

Overview

PT-141, generic name bremelanotide, is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH). It is the peptide with the most mature human clinical evidence base referenced on this site: the FDA approved bremelanotide (brand name Vyleesi) in 2019 for premenopausal hypoactive sexual desire disorder, following two large Phase 3 trials (the RECONNECT studies, which together enrolled over 1,200 subjects).

Proposed Mechanism of Action

Unlike phosphodiesterase-5 (PDE5) inhibitors, which act on peripheral vasculature, bremelanotide acts centrally, agonizing melanocortin 3 and 4 receptors (MC3R/MC4R) in the hypothalamus and limbic regions implicated in sexual arousal and motivation.

Research Context

The Molinoff et al. (2003) paper reports early trial data showing dose-dependent increases in erectile activity in both normal men and men with erectile dysfunction following PT-141 administration, historically via intranasal delivery. The later-approved subcutaneous formulation (studied in the RECONNECT trials and in the cardiovascular-safety study by Jayne et al., 2017, which specifically monitored blood pressure effects) is the version that reached FDA approval.

Regulatory Status

Because bremelanotide is FDA-approved as a prescription drug (Vyleesi) for a specific indication, compounded or research-grade "PT-141" sold outside that regulatory pathway is not the same regulatory product, even where the underlying molecule is identical — sourcing, purity, and formulation are not guaranteed outside the approved supply chain.

Limitations of the Current Evidence

• The abstracts reviewed here do not specify exact milligram dosing; refer to the full RECONNECT trial publications and the Vyleesi FDA label for verified human dosing data rather than third-party summaries.
• Known side effects in the approved trials included nausea and blood-pressure changes — see the Jayne et al. (2017) study specifically for cardiovascular monitoring data.