Somatostatin
SST · SRIF · Somatotropin Release-Inhibiting Factor
A 14 (or 28) amino acid cyclic inhibitory neuropeptide produced throughout the body that suppresses growth hormone, insulin, glucagon, and multiple other hormones; the endogenous counterbalance to GHRH.
Half-Life
1–3 minutes (intravenous, native SST-14); SST-28 slightly longer; octreotide ~100 minutes; lanreotide LAR ~28 days
MW
1637.9 Da (SST-14)
Amino Acids
14 AA
Evidence
Clinical
Regulatory Status
Native somatostatin infusion used in some clinical settings. Synthetic analogues (octreotide/Sandostatin, lanreotide/Somatuline) are FDA-approved for acromegaly, carcinoid tumors, VIPomas, GI bleeding. Pasireotide (Signifor) FDA-approved for Cushing's disease.
In Plain English
The body's main "pause" button for growth hormone and several other hormones. While GHRH pushes the pituitary to release GH, somatostatin acts like a parking brake — stopping the release. It also inhibits insulin, glucagon, and many GI hormones, making it a master regulator of the body's metabolic signaling. Because it breaks down in seconds, doctors use longer-acting synthetic versions to treat conditions like acromegaly (too much GH) and carcinoid tumors.
Overview
Somatostatin is a naturally produced cyclic peptide hormone synthesized in the hypothalamus, pancreatic delta cells, gastrointestinal tract, and throughout the CNS. It is the physiological off-switch for growth hormone release (opposing GHRH) and also inhibits insulin, glucagon, TSH, gastrin, cholecystokinin, secretin, and numerous other peptides. Two naturally occurring forms exist: SST-14 (predominant in the brain/GI tract) and SST-28 (produced in intestinal mucosa). Because native somatostatin has an extremely short half-life (~1-3 minutes), longer-acting synthetic analogues — octreotide, lanreotide, and pasireotide — were developed for clinical use in acromegaly, carcinoid tumors, and Cushing's disease.
Common Formats
- Intravenous infusion (native SST-14, very short half-life)
- Lyophilized powder (research)
- Long-acting analogues in depot injection form
Storage Notes
Native somatostatin: requires cold chain, use promptly after reconstitution. Synthetic analogues (octreotide/lanreotide): refrigerate, depot formulations room-temperature stable briefly.
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Related Compounds
CJC-1295
A long-acting GHRH analogue with a Drug Affinity Complex that extends its half-life dramatically, allowing weekly dosing for sustained GH elevation.
Ipamorelin
A highly selective GH secretagogue and ghrelin receptor agonist known for clean GH release without significant cortisol or prolactin stimulation.
Sermorelin
A 29-amino acid truncated analogue of endogenous GHRH, FDA-approved for pediatric GHD and widely researched for anti-aging and body composition.
GHRP-2
A potent GH secretagogue with strong ghrelin receptor activity, producing significant GH pulses with some cortisol and prolactin elevation.
Cortistatin
A neuropeptide structurally related to somatostatin but with distinct immunomodulatory properties, researched for anti-inflammatory effects in autoimmune and inflammatory disease models including Crohn's disease, rheumatoid arthritis, and sepsis.
Educational Disclaimer: All information on this page is for educational and research purposes only. This does not constitute medical advice, diagnosis, or treatment recommendation. Consult a qualified healthcare professional.