PT-141 (Bremelanotide)

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide belonging to the class of melanocortin receptor agonists. Structurally, it is a derivative of a fragment of alpha-melanocyte-stimulating hormone (α-MSH) in which five internal amino acids are closed into a ring by a lactam bridge (sequence Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys). In in vitro research models it acts as a melanocortin receptor ligand with affinity for the MC1R, MC3R, MC4R and MC5R subtypes; functional activity at MC3R and MC4R is considered the most significant. Binding to MC4R initiates the Gs protein signalling cascade and the associated intracellular response. This information is provided for scientific context only.

In laboratory in vitro models, this peptide is used as a tool for studying melanocortin receptor signalling: how agonist binding to MC4R initiates the Gs protein cascade, adenylate cyclase activation and intracellular cAMP accumulation, as well as secondary activity of the phospholipase C and ERK/MAPK pathways in neuronal cells. Bremelanotide is also used in structural studies as an agonist that stabilises the MC4R–Gs complex for cryo-electron microscopy (cryo-EM) analysis; such a structural model of the bremelanotide–MC4R–Gs complex has been deposited in the public Protein Data Bank (PDB entry 7F55, Cell Research, 2021). This information is provided for research context only and is not an instruction for use.

The product is supplied as a high-grade laboratory lyophilised (dry) powder. Each vial contains 10 mg of the active substance – PT-141 (bremelanotide), ≥99% purity (HPLC). Before in vitro work, the powder is reconstituted with bacteriostatic water, which is sold separately. The solvent is introduced slowly along the side of the vial and swirled gently until a clear solution forms; do not shake the vial.

Keep the unopened vial of dry lyophilised powder in a refrigerator at +2 to +8 °C, protected from light. For longer storage, a freezer (−20 °C) is recommended. Keep the reconstituted solution (dissolved in bacteriostatic water) refrigerated and use it within the time set out in your research protocol. Avoid repeated freeze–thaw cycles so as not to compromise the stability of the peptide structure.

In structural and pharmacological in vitro research, bremelanotide is often examined alongside other melanocortin receptor ligands – endogenous α-MSH and other peptide or small-molecule agonists – to compare binding modes and receptor subtype selectivity. In functional models it is combined with MC4R-expressing cell lines and with Gs protein and cAMP detection systems (e.g. reporter or cAMP accumulation assays). Specific combinations depend on the research protocol; no usage or dosing instructions are given.

Absolutely not. This product is sold exclusively for laboratory research and scientific experiments. It is not intended for human or animal consumption and is not a medicine, dietary supplement or cosmetic product.