Important: FDA approval is specifically for HSDD in premenopausal women. Use in men or for other sexual dysfunction indications is not supported by the pivotal trial data. Research-grade PT-141 from Purgo Labs is for laboratory use only and differs from the clinical Vyleesi® formulation.
Overview
PT-141, clinically known as bremelanotide, is a synthetic cyclic heptapeptide melanocortin receptor agonist derived from Melanotan II. It is FDA-approved under the brand name Vyleesi® for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women, making it one of the few peptides in this catalog with full regulatory approval and extensive human clinical data. Unlike phosphodiesterase-5 (PDE5) inhibitors such as sildenafil, which act peripherally on vascular smooth muscle, PT-141 acts centrally through melanocortin receptors in the brain — specifically MC3R and MC4R in the hypothalamus and limbic system. This central mechanism of action represents a fundamentally different approach to sexual dysfunction research.
Mechanism of Action
PT-141 exerts its primary effects through agonism at MC3R and MC4R in the central nervous system, particularly in the hypothalamus, limbic system, and spinal cord. MC4R activation in the medial preoptic area (MPOA) of the hypothalamus — a region critical for sexual motivation and behavior — increases dopaminergic neurotransmission in the mesolimbic pathway, enhancing sexual desire and arousal. Unlike PDE5 inhibitors, which require sexual stimulation to be effective and act primarily on penile/clitoral blood flow, PT-141 modulates the central neural circuits that generate sexual desire. This distinction is clinically significant: PT-141 can increase sexual motivation in the absence of extern
Research Evidence
- FDA-approved (Vyleesi®) for hypoactive sexual desire disorder (HSDD) in premenopausal women
- Central mechanism: MC3R/MC4R agonism in hypothalamus — distinct from peripheral PDE5 inhibitors
- Increases dopaminergic neurotransmission in mesolimbic pathway, enhancing sexual desire
- Effective in both male and female sexual dysfunction models (Diamond et al., 2006)
- Cyclic structure derived from MT2 with C-terminal modification reducing melanogenic activity
Bottom line: PT-141 is FDA-approved as Vyleesi® for female sexual desire disorder, giving it one of the strongest clinical validation profiles in this catalog. Its central mechanism — working through the brain rather than blood vessels — distinguishes it from conventional sexual health drugs. The research-grade peptide supplied by Purgo Labs is for laboratory use only.
Research Protocols & Dosage
Evidence-based research protocols, administration routes, and dosage considerations for PT-141 are detailed in the full compound profile. See also: Dosage guide for PT-141.
Sourcing & Quality
PT-141 is available from Purgo Labs with third-party COA verification and research-grade purity standards. View PT-141 at Purgo Labs.