PT-141, also known as Bremelanotide, is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH and a molecular weight of approximately 1,025.18 Da. PT-141 is a metabolite of Melanotan 2 (MT-2) and functions as a non-selective melanocortin receptor agonist with primary research interest centered on MC3R and MC4R signaling pathways. This compound is distinguished from other melanocortin agonists by its central nervous system-mediated mechanism of action, making it a valuable tool for melanocortin neurobiology research.
In hypothalamic neuronal cell models, PT-141 activates MC4R through Gs-coupled adenylyl cyclase signaling, increasing intracellular cAMP levels and downstream CREB phosphorylation. MC4R is densely expressed in the paraventricular nucleus and medial preoptic area, regions extensively studied in neuroendocrine regulation research. In receptor binding assays, PT-141 demonstrates nanomolar affinity for MC4R and MC3R, with reduced activity at MC1R compared to its parent compound MT-2. This relative selectivity profile positions PT-141 as a useful tool for dissecting MC3R/MC4R-specific signaling from MC1R-mediated melanogenic responses.
In vitro studies using MC4R-transfected cell lines (HEK293-MC4R) have characterized PT-141 as a partial agonist at MC4R in certain assay configurations, with concentration-response profiles distinct from the endogenous agonist α-MSH. cAMP accumulation assays and β-arrestin recruitment studies suggest that PT-141 may exhibit biased agonism at melanocortin receptors, an area of active investigation in GPCR pharmacology research.
Additional research applications include investigation of melanocortin signaling in autonomic nervous system regulation, as MC4R activation in brainstem cell models has been associated with modulation of sympathetic outflow markers. In adipocyte models, MC3R agonism by PT-141 has been studied for effects on lipid metabolism pathways. Comparative receptor pharmacology studies frequently employ PT-141 alongside selective MC receptor antagonists such as SHU9119 and HS024 to delineate receptor subtype contributions.
Erosyn Labs provides PT-141 (Bremelanotide) as a lyophilized powder at ≥98% purity by HPLC with mass spectrometry identity confirmation. A comprehensive Certificate of Analysis accompanies each lot. Reconstitution in bacteriostatic water is recommended. Store lyophilized material at -20°C. Reconstituted solutions should be maintained at 2–8°C and utilized within 21 days. Standard aseptic peptide handling protocols apply.
For research and laboratory use only. Not for human consumption.
