CHH is the most abundant hormone in the sinus gland of isopods and decapods which controls the blood sugar level. Has a secretagogue action over the amylase released from the midgut gland. May act as a stress hormone. MIH may inhibit Y-organs where molting hormone (ecdysteroid) is secreted and a molting cycle is initiated when MIH secretion diminishes or stops. Produced by the medulla terminalis X-organ in the eyestalks and transported to the sinus gland where they are stored and released. Present also in the ventral nervous system. Stereoinversion of L-Phe (form CHH-A-I) to D-Phe (form CHH-A-II). Belongs to the arthropod CHH/MIH/GIH/VIH hormone family.