ACTH 22-39 trifluoroacetate is a synthetic peptide fragment derived from the C-terminal region of adrenocorticotropic hormone (ACTH). It is primarily used in research to study melanocortin receptor (MC3R and MC4R) binding and signaling pathways, particularly in the central nervous system. This fragment exhibits agonist activity at these receptors, aiding investigations into anti-inflammatory effects, modulation of feeding behavior, sexual function, neuroprotection, and immune regulation. Unlike the N-terminal ACTH fragments, it does not significantly stimulate steroidogenesis or adrenal cortisol release. Commonly employed in in vitro biochemical assays with neuronal, immune, and pituitary cell cultures, as well as in vivo animal models to explore non-adrenal roles of melanocortin peptides.