Thyrotropin-releasing hormone (TRH), a tripeptide produced by the hypothalamus, stimulates the pituitary gland to release thyroid-stimulating hormone (Thyrotropin). Thyrotropin then stimulates the thyroid gland to synthesize and release thyroid hormones. TRH is a regulator of metabolic homeostasis. In rodents, TRH has been shown to regulate several metabolic and behavioral parameters, including food intake and locomotor activity. TRH and TRH analogs seem to possess anorexigenic capacities, with a likely site of action in the hypothalamus. TRH produces antidepressant effects and acts through at least two known G-protein coupled receptors, TRH-R1 and TRH-R2.