PT-141 (Bremelanotide): A Central Melanocortin Research Guide
By Peptura Research Team/17 May 2026/6 min read
What PT-141 Is
PT-141, also known as Bremelanotide, is a synthetic cyclic heptapeptide derived from the structure of Melanotan II. Palatin Technologies developed it by reworking Melanotan II to drop the C-terminal amide behind MC1R binding while keeping activity at the central melanocortin receptors MC3R and MC4R. The outcome is a peptide with much reduced melanogenic effect and its action focused on the central-nervous-system receptors tied to sexual desire and arousal signalling.
The MC3R and MC4R Mechanism
PT-141 acts as an agonist at MC4R and, to a lesser degree, MC3R. MC4R is densely expressed in the paraventricular nucleus of the hypothalamus and other central regions bound up with energy homeostasis, sexual behaviour, and inflammation control. When PT-141 activates MC4R in research models, it reaches sexual arousal pathways through a central route quite unlike the peripheral vascular action of PDE5 inhibitors. Sitting downstream of dopaminergic signalling, the MC4R pathway is thought to govern the initiation of desire and arousal rather than the vascular side of erectile response.
Set Against Melanotan II
PT-141 and Melanotan II share a structural origin but diverge in pharmacology. Melanotan II activates MC1R, MC3R, MC4R, and MC5R, with pronounced pigmentation effects. PT-141 removes the MC1R activity and concentrates at the central receptors. Where a research model needs central melanocortin activation without melanogenic confounders, PT-141 is usually the pick over Melanotan II. The Melanotan I vs Melanotan II comparison gives further context on the wider receptor family.
Research Background
Bremelanotide holds clinical approval in the United States for hypoactive sexual desire disorder in pre-menopausal women, marketed as Vyleesi. That approval is specific to the United States and does not extend to the UK, where Bremelanotide is not approved for human use by the MHRA. Peptura supplies PT-141 as a research-grade peptide for in-vitro laboratory use only.
Laboratory Handling
PT-141 comes as lyophilised powder. Store at -20°C before reconstitution. Reconstitute with bacteriostatic water by running the diluent slowly down the side of the vial and swirling gently. Never shake. Keep reconstituted solutions at 2-8°C and use within four weeks, avoiding repeated freeze-thaw cycles.
Sourcing in the UK
Peptura supplies research-grade PT-141 10mg with full third-party Certificate of Analysis on every product page. Same-day UK dispatch on orders placed before 2pm GMT, free Royal Mail Tracked shipping over £45. For in-vitro laboratory research use only, not for human consumption.
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Disclaimer: This article is for research and educational purposes only. All information provided is not intended as medical advice. Peptura products are not for human consumption and are sold strictly for laboratory research use only.