PT-141

PT-141 (Bremelanotide, formerly referred to as PT-141 in development) is a cyclic heptapeptide melanocortin receptor agonist derived from Melanotan II through removal of the C-terminal amide group and structural optimization. It is the active metabolite of Melanotan II following metabolic processing and acts primarily on MC3R and MC4R, which are expressed centrally in the hypothalamus, brainstem, and spinal cord.

Unlike PDE5 inhibitors (sildenafil, tadalafil) that work through vascular mechanisms, PT-141 activates pro-erectile and pro-sexual arousal neural pathways centrally. It is FDA-approved as Vyleesi (bremelanotide injection) for hypoactive sexual desire disorder (HSDD) in premenopausal women — the first approved centrally acting drug for a female sexual dysfunction. Research applications include central neural pathways of sexual arousal, melanocortin system behavioral pharmacology, and comparative studies with PDE5 inhibitors.

• MC3R/MC4R central nervous system pharmacology and behavioral effects
• Neural pathways of sexual arousal, desire, and motivation research
• Comparison with PDE5 inhibitors: central vs peripheral mechanisms
• Hypoactive sexual desire disorder (HSDD) preclinical models
• Hypothalamic melanocortin system and feeding/sexual behavior integration
• Female sexual dysfunction pharmacology research

Dose levels referenced by the MVLabs peptide calculator, shown for research reference only:

Melanocortin agonist. Max 2 mg per use. No more than once every 72 h.

Research reference only — not dosing guidance for human use. Use the calculator for other vials or volumes.

Supplied as a lyophilized powder. Store at 2–8 °C on receipt; protect from heat, light and moisture, and avoid excessive agitation. If reconstitution is required for laboratory work, use sterile technique — bacteriostatic water, or 0.6% acetic acid for low-solubility peptides. Protocols vary by research application.