Growth hormone (GH) secretion from the anterior pituitary is primarily regulated by two hypothalamic hormones – growth hormone releasing hormone (GHRH) and somatostatin [1][2]. GHRH is secreted from the arcuate nucleus and stimulates GH release. Somatostatin is secreted from the periventricular nucleus and inhibits GH release [1][3]. The balance between GHRH and somatostatin signaling generates pulsatile GH secretion, with somatostatin inhibiting the peaks [2][4].

GH secretion is also modulated by neurotransmitters. Dopamine, norepinephrine and GABA inhibit GH, likely by stimulating somatostatin release [3][5]. In contrast, ghrelin and neuropeptide Y stimulate GH, potentially by inhibiting somatostatin [1][6]. Negative feedback by IGF-1 suppresses GHRH release when GH levels are elevated [1][4]. Together, these neural and hormonal signals regulate GH levels to support growth and metabolism. Disruptions in GH pulsatility can lead to growth disorders or acromegaly [2][5].