Scientific Glossary

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Somatostatin (also called growth hormone-inhibiting hormone, GHIH) provides the off-signal in GH regulation, balancing GHRH's stimulatory effects. Endogenous somatostatin release is triggered by high GH levels (negative feedback), hyperglycemia, and high fat/protein intake. Pharmaceutical somatostatin analogues (octreotide, lanreotide) suppress GH in acromegaly treatment. Understanding somatostatin helps explain why timing of research protocols matters — factors that elevate somatostatin (glucose, fatty acids) theoretically blunt GH responses to secretagogues.