Recognizing that the secretion of GH by the pituitary is controlled by both stimulating and inhibiting signals from the hypothalamus [i.e., both GH-releasing hormone (GHRH) and GH-inhibiting hormone (GHIH)], researchers treated fibromyalgia patients with pyridostigmine, a drug that inactivates the inhibiting effect of GHIH. Here, GH1 is linked to fibromyalgia.