The peptide CRF, also known as the Corticotropin Releasing Factor is a 14 amino acid neuropeptide which is produced by the hypothalamus, within the hypothalamic-pituitary adrenal axis in response to stress stimuli. The CRF family exert their function by binding to Corticotropin-releasing factor receptors 1 and 2. During stress the production of CRF stimulates downstream hormones such as glucocorticoids and adrenocorticotropin (ACTH) through binding to CRF1 in the anterior pituitary gland. A negative feedback look is generated through glucocorticoids thus preventing the further release of CRF from the hypothalamus.

Studies have shown CRF to be overproduced in patients with depression and can contribute to symptoms such as, reduced quality of sleep, anxiety, reduced appetite and analgesia. Furthermore higher CRF levels has been associated with immune cell dysfunction through preventing T-cell proliferation.