ACTH 1-39 is a synthetic form of adrenocorticotropic hormone corresponding to the full biologically active sequence of ACTH. It plays an important role in research involving the hypothalamic-pituitary-adrenal axis and adrenal steroidogenesis. ACTH-related research is relevant to studies of endocrine signaling, adrenal function, hormone regulation, and physiological responses involving corticosteroid production.