PT-141 — 10mg

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH), derived from the parent compound Melanotan-II through structural refinement to shift its pharmacological activity away from skin pigmentation and toward central melanocortin receptor activation. The compound binds melanocortin receptors MC1R, MC3R, MC4R, and MC5R with varying affinity, but its primary pharmacological relevance is at MC3R and MC4R in the central nervous system, particularly within the paraventricular nucleus of the hypothalamus.

Unlike peripheral vasoactive agents for sexual dysfunction (PDE5 inhibitors like sildenafil, which increase penile blood flow through nitric oxide pathways), PT-141 acts centrally to modulate sexual arousal at the level of hypothalamic signaling — a mechanistically distinct pathway that produces effects in both men and women and operates independently of circulatory function. This central action was validated by the compound's regulatory approval trajectory: bremelanotide was approved by the FDA in 2019 as Vyleesi for the on-demand treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women — the first centrally-acting agent for this indication and one of only two FDA-approved HSDD pharmacotherapies.

Research applications span both clinical (male and female sexual dysfunction, post-SSRI sexual dysfunction) and mechanistic (melanocortin system pharmacology, central vs peripheral sexual arousal pathways) contexts. PT-141 has also been studied in autoimmune and inflammatory conditions where MC3R/MC4R modulation produces immunomodulatory effects distinct from the peptide's classical indication. Its subcutaneous pharmacokinetics produce onset within 45 minutes and a duration of approximately 24 hours, supporting the on-demand dosing strategy that characterized the Vyleesi clinical program.