PT-141 — questions, answered plainly.

PT-141 is the development name for bremelanotide, a cyclic heptapeptide melanocortin receptor agonist derived from α-melanocyte-stimulating hormone (α-MSH). It is FDA-approved as Vyleesi for a single specific indication.

Vyleesi is FDA-approved for acquired, generalised hypoactive sexual desire disorder (HSDD) in premenopausal women. The Dhillon 2019 Drugs review (PMID 31429064) summarises the regulatory evidence supporting approval.

PT-141 acts on the central melanocortin system (particularly MC4R neurons in the central nervous system). PDE5 inhibitors (sildenafil, tadalafil) act peripherally on the nitric oxide / cGMP pathway in vascular smooth muscle. Different mechanisms, different intended populations.

The melanocortin system comprises α-MSH and related peptides acting at five melanocortin receptors (MC1R–MC5R). The Sweeney 2023 Nature Reviews Endocrinology review (PMID 37365323) discusses central melanocortin pharmacology, including bremelanotide and the related compound setmelanotide.

Diamond et al. 2006 (J Sex Med, PMID 16839319; n=18) was a double-blind crossover study of intranasal PT-141 in premenopausal women with sexual arousal disorder. A single dose was associated with increased reported sexual desire and arousal satisfaction versus placebo. The approved Vyleesi formulation is subcutaneous, not intranasal.

Reported adverse effects in trials include transient increases in blood pressure. Approval comes with specific patient-selection criteria. Clinical use is a medical decision with a qualified healthcare professional; Palthera does not provide dosing or administration guidance.