PT-141

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH. Structurally it is the C-terminal carboxylic acid analog of melanotan II (which is C-terminal amidated). PT-141 was developed by Palatin Technologies as a melanocortin receptor agonist research compound for in vitro and preclinical study, sold here strictly for research use only.

PT-141 is a non-selective melanocortin receptor agonist with preferential functional potency at MC3R and MC4R over MC1R, and weaker activity at MC5R. In transfected cell lines it activates G-alpha-s-coupled adenylyl cyclase, producing dose-dependent cAMP accumulation that serves as the standard in vitro readout for melanocortin receptor characterization.

A side-chain lactam bridge between Asp2 and Lys7 cyclizes the backbone and locks the conserved His-D-Phe-Arg-Trp melanocortin pharmacophore into an active conformation. This constraint, together with the D-Phe7 substitution, increases enzymatic stability and receptor potency compared with linear alpha-MSH analogs.

In rodent preclinical models, PT-141 is used as a tool compound to study MC4R-expressing hypothalamic and limbic circuits. Investigators combine it with MC4R-selective antagonists or MC4R knockout models to isolate central, MC4R-mediated responses from peripheral or off-target mechanisms. Earlier work with melanotan II (Wessells et al., 2000) established the central, melanocortin-mediated framework that later PT-141 studies extended.

No. GlamCO PT-141 is sold strictly as a research chemical for in vitro melanocortin receptor pharmacology and preclinical investigation. It is not a drug, supplement, cosmetic, or food, and is not intended for human or veterinary diagnostic or therapeutic use.

Lyophilized PT-141 should be stored at -20°C for long-term stability and protected from light. After reconstitution in bacteriostatic water, store at 2-8°C and use within 14 days. Avoid repeated freeze-thaw cycles, which can degrade the cyclic peptide.