Vasopressin-d5 TFA is the TFA salt form of Vasopressin-d5, an isotopically labeled derivative of Vasopressin. Vasopressin, a cyclic nonapeptide, is synthesized in the medial hypothalamus and plays a critical role in the hypothalamic-pituitary-adrenal axis by enhancing the stimulation of corticotropin-releasing factor, thereby regulating the secretion of adrenocorticotropic hormone. Additionally, Vasopressin acts as a neurotransmitter, exerting its effects through interaction with specific G-protein-coupled receptors.