PT-141 (Bremelanotide) Research Guide — Melanocortin Agonist Mechanism & Applications

PT-141 (Bremelanotide): Melanocortin Receptor Agonist Research Profile

PT-141, also known as bremelanotide, is a synthetic cyclic heptapeptide melanocortin receptor agonist. Originally developed as a metabolite of Melanotan 2, PT-141 was specifically optimized for MC4R activation. It became the first melanocortin-based therapy to receive FDA approval (as Vyleesi) for hypoactive sexual desire disorder (HSDD) in premenopausal women, making it a landmark compound in melanocortin research.

Molecular Profile

Parameter	Specification
Generic Name	Bremelanotide
Sequence	Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH
Molecular Formula	C₅₀H₆₈N₁₄O₁₀
Molecular Weight	1025.17 g/mol
CAS Number	189691-06-3
Primary Target	MC4R (melanocortin-4 receptor)
FDA Status	Approved (Vyleesi, 2019)

Mechanism of Action

PT-141 acts as an agonist at the melanocortin-4 receptor (MC4R) in the central nervous system. Unlike PDE5 inhibitors (sildenafil, tadalafil) which act peripherally on vascular smooth muscle, PT-141 works centrally through hypothalamic pathways. MC4R activation in the medial preoptic area and paraventricular nucleus of the hypothalamus initiates downstream signaling that modulates sexual arousal and desire through central nervous system pathways rather than peripheral vasodilation.

Clinical Research Highlights

RECONNECT Trials

The pivotal RECONNECT phase 3 trials in premenopausal women with HSDD demonstrated statistically significant increases in desire domain scores, increased satisfying sexual events, and reduced distress associated with low sexual desire. These trials led to FDA approval in June 2019.

Male Sexual Dysfunction Research

Earlier phase 2 studies investigated PT-141 in men with erectile dysfunction. Results showed efficacy in patients who had failed PDE5 inhibitor therapy, suggesting the central mechanism offers an alternative pathway for cases where peripheral vasodilators are insufficient.

PT-141 vs PDE5 Inhibitors

Feature	PT-141	PDE5 Inhibitors (Sildenafil etc.)
Mechanism	Central (MC4R agonist)	Peripheral (PDE5 inhibition)
Site of Action	Hypothalamus	Penile vasculature
Affects Desire	Yes	No
Affects Arousal	Yes	Yes (erectile function)
Administration	Subcutaneous injection	Oral
Female Efficacy	Yes (FDA-approved)	Limited evidence
Blood Pressure Effect	Transient mild increase	Decrease (vasodilation)

Research-Grade PT-141 from Aarise Healthcare

Aarise Healthcare supplies research-grade PT-141/Bremelanotide (≥98% HPLC) for qualified research applications. Browse our peptide catalog or contact us for institutional pricing.