Quick summary
Octreotide (Sandostatin) is an FDA-approved synthetic somatostatin analog used to treat acromegaly, carcinoid tumors, and VIPomas. Available as short-acting injections and a long-acting monthly depot (Sandostatin LAR), it suppresses GH, IGF-1, and various GI hormones.
Overview
Octreotide is a synthetic octapeptide analogue of the natural hormone somatostatin, FDA-approved for the treatment of acromegaly, carcinoid tumor-related diarrhea, and vasoactive intestinal peptide-secreting tumors (VIPomas). It is far more potent and longer-acting than endogenous somatostatin and is used worldwide in clinical endocrinology and gastroenterology.
Mechanism of action
Octreotide binds preferentially to somatostatin receptors SSTR2 and SSTR5, mimicking the inhibitory actions of endogenous somatostatin but with significantly greater potency and duration. It suppresses secretion of growth hormone (GH), IGF-1, insulin, glucagon, gastrin, secretin, motilin, vasoactive intestinal peptide (VIP), and serotonin. By reducing splanchnic blood flow, it also decreases portal hypertension. In acromegaly, it normalizes GH levels in approximately 50% of patients and IGF-1 in 50–60%. Its mechanism involves Gi protein-coupled receptor signaling that decreases intracellular cAMP, reduces calcium influx, and opens potassium channels, collectively suppressing hormone exocytosis from secretory cells.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| acromegaly | subcutaneous | 50–600 mcg | three times daily | Start at 50 mcg TID; titrate based on GH/IGF-1 response. Maximum 1500 mcg/day. |
| carcinoid tumors / VIPoma | subcutaneous | 100–600 mcg | two to three times daily | Start at 100–600 mcg/day in 2–4 divided doses. Adjust based on symptom control. |
| long-acting (Sandostatin LAR) | intramuscular | 10–30 mg | once every 28 days | After stabilization on SC octreotide. Switch to LAR 20 mg IM monthly; adjust to 10 or 30 mg based on response. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Octreotide has been extensively studied across decades of clinical trials supporting its FDA-approved indications. In acromegaly, it reduces GH to normal in ~50% of patients and shrinks pituitary tumors in many cases. In carcinoid syndrome, it significantly reduces diarrhea and flushing episodes. Long-acting formulations (Sandostatin LAR) dosed monthly have equivalent efficacy to thrice-daily injections. Off-label use includes GI bleeding and dumping syndrome with supporting clinical evidence.[1][2][3][4][5]
Evidence grading
Each claimed benefit is graded by the strength of available evidence. Grades reflect study quality, not effect size.
Strong = multiple RCTs · Moderate = limited trials or observational · Preliminary = animal or in vitro only · Insufficient = anecdotal or no published data
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Octreotide for synergistic effects.
Legal status
FDA-approved drug (NDA 019667, first approved 1988). Available only by prescription as Sandostatin injection and Sandostatin LAR depot. Administered in clinical or hospital settings; not available as a research chemical.
Sourcing & access
Prescription required
Octreotide is an FDA-approved prescription medication available through licensed healthcare providers, telehealth platforms, and 503A/503B compounding pharmacies.
Frequently asked questions
Octreotide (Sandostatin) is FDA-approved for the treatment of acromegaly, carcinoid tumors, and vasoactive intestinal peptide-secreting tumors (VIPomas). It suppresses growth hormone and IGF-1 secretion and controls symptoms from hormone-secreting tumors.
Octreotide mimics the natural hormone somatostatin by binding to somatostatin receptors SSTR2 and SSTR5 on pituitary and tumor cells. This inhibits the release of growth hormone, insulin, glucagon, and various GI hormones, suppressing both hormone secretion and tumor growth.
Sandostatin LAR is the long-acting depot formulation of octreotide, administered once every 28 days via intramuscular injection at doses of 10 to 30 mg. It is used after patients are stabilized on short-acting subcutaneous octreotide.
Common side effects include nausea, abdominal cramps, diarrhea, steatorrhea, and gallstone formation. Long-term use may cause hyperglycemia or hypoglycemia, bradycardia, and hypothyroidism. Injection site pain is common with the short-acting formulation.
Yes, gallstone formation (cholelithiasis) is a well-documented side effect of long-term octreotide use, occurring in approximately 15 to 30 percent of patients. This is due to reduced gallbladder motility and altered bile composition from somatostatin receptor activation.
Research references
- Octreotide treatment of acromegaly. A randomized, multicenter studyPubMed
- Debut of a somatostatin analog: octreotide in reviewPubMed
- Clinical review 23: The use of the long-acting somatostatin analog octreotide in the treatment of gut neuroendocrine tumorsPubMed
- Somatostatin analogues in acromegaly and gastroenteropancreatic neuroendocrine tumours: past, present and futurePubMed
- Chronic treatment with the somatostatin analog octreotide improves cardiac abnormalities in acromegalyPubMed