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approvedGrowth Hormone

Octreotide

Also known as: Sandostatin, Sandostatin LAR, SMS 201-995

Octreotide is a synthetic octapeptide analog of somatostatin with a dramatically extended half-life (~90 minutes vs ~2 minutes for native somatostatin) and preferential binding to somatostatin receptor subtype 2 (SSTR2). FDA-approved in 1988 as Sandostatin, it is the most widely used somatostatin analog worldwide. Available as short-acting subcutaneous injections and long-acting depot (LAR) formulation, it is the standard of care for acromegaly and carcinoid syndrome, with additional uses in variceal bleeding, diarrhea management, and neuroendocrine tumor control.

4 cited references·5 researched benefits

Quick Answer

Octreotide (Sandostatin) is a synthetic somatostatin analog with 40× the potency and 45× longer half-life than native somatostatin. FDA-approved since 1988, it is the most widely prescribed somatostatin analog for acromegaly (normalizes IGF-1 in 50–65% of patients), carcinoid syndrome (controls flushing/diarrhea in 70–80%), and neuroendocrine tumors (CLARINET/PROMID trials showed tumor stabilization). Available as subcutaneous injection and monthly LAR depot.

Key Facts

Mechanism
Octreotide is an 8-amino-acid cyclic peptide incorporating D-amino acids for enzymatic resistance. It binds SSTR2 with high affinity (50–100× native SST) and moderate SSTR5 affinity, with minimal activity at SSTR1/3/4. Receptor activation inhibits adenylyl cyclase, opens K+ channels, and closes Ca²+ channels, suppressing hormone secretion from pituitary somatotrophs (GH), GI endocrine cells (gastrin, VIP, serotonin), and pancreatic islet cells (insulin, glucagon). Antiproliferative effects through SSTR2-mediated cell cycle arrest (p27 upregulation) and apoptosis contribute to tumor growth control in neuroendocrine neoplasms.
Research Status
approved
Half-Life
~90 minutes (SC); ~28 days (LAR depot)
Molecular Formula
C₄₉H₆₆N₁₀O₁₀S₂
Primary Use
Growth Hormone
Table of Contents

Benefits

  • Acromegaly control — normalizes GH and IGF-1 levels in 50–65% of patients, reducing symptoms and comorbiditiesstrong
  • Carcinoid symptom relief — controls flushing and diarrhea in 70–80% of patients with carcinoid syndromestrong
  • Neuroendocrine tumor stabilization — PROMID and CLARINET trials demonstrated significant progression-free survival benefitstrong
  • Variceal bleeding control — IV octreotide reduces portal pressure and is first-line therapy for acute variceal hemorrhagestrong
  • Refractory diarrhea — effective for chemotherapy-induced, AIDS-related, and post-surgical diarrhea unresponsive to other treatmentsmoderate

Dosage Protocols

RouteDosage RangeFrequencyNotes
Subcutaneous injection (Sandostatin)50–200 mcg2–3× dailyShort-acting formulation for dose titration and acute situations. Used for initial dose finding before converting to LAR depot. Also used as rescue medication for breakthrough carcinoid symptoms.
Intramuscular depot (Sandostatin LAR)10–40 mgEvery 28 daysLong-acting release formulation using biodegradable microspheres. Standard doses: 20 mg for acromegaly (adjust based on GH/IGF-1 levels), 30 mg for neuroendocrine tumors. Must be injected by healthcare professional into gluteal muscle.
Intravenous infusion (acute care)25–50 mcg/hourContinuous infusion for 2–5 daysUsed in hospital settings for acute variceal bleeding. Bolus 25–50 mcg IV followed by continuous infusion. Continued for 2–5 days in conjunction with endoscopic therapy.

Medical disclaimer

Dosage information is provided for educational reference only. Always follow your prescriber's instructions and consult a qualified healthcare provider before starting any peptide protocol.

Side Effects

  • Gallstones — occur in 15–30% of patients on long-term therapy due to reduced gallbladder motility and bile stasiscommon
  • Gastrointestinal effects — nausea, abdominal pain, bloating, and steatorrhea (fat malabsorption) in 10–30% of patientscommon
  • Hyperglycemia — impaired insulin secretion can worsen glucose tolerance; monitor in diabetic patientscommon
  • Injection-site pain — particularly with subcutaneous formulation; LAR depot can cause injection-site nodulescommon
  • Bradycardia — sinus bradycardia reported in 5–25%, usually asymptomatic but monitor in cardiac patientsrare

Frequently Asked Questions

What is the difference between Sandostatin and Sandostatin LAR?
Sandostatin (immediate-release) requires 2–3 subcutaneous injections daily and is used for dose titration, acute situations, and breakthrough symptoms. Sandostatin LAR (Long-Acting Release) is injected intramuscularly once monthly using microsphere technology that provides sustained drug release over 28 days. Most patients start on immediate-release for dose optimization, then convert to the equivalent LAR dose for maintenance therapy. LAR greatly improves convenience and adherence.
How effective is octreotide for acromegaly?
Octreotide LAR normalizes IGF-1 in approximately 50–65% of acromegaly patients and reduces GH to <2.5 ng/mL in 50–60%. It also reduces tumor size by ≥20% in approximately 30–50% of patients (more in treatment-naïve patients). It is used as first-line medical therapy for acromegaly, as adjunct after incomplete surgical resection, or as pre-operative treatment to reduce tumor size and improve surgical outcomes. Patients who don't respond adequately may switch to pasireotide or add pegvisomant.
Why does octreotide cause gallstones?
Octreotide inhibits cholecystokinin (CCK) release and directly suppresses gallbladder contraction, reducing gallbladder emptying by 50–70%. This bile stasis, combined with altered bile composition (increased cholesterol saturation), promotes gallstone formation. The risk increases with treatment duration: ~15% at 1 year, ~25–30% at 3+ years. Most gallstones are asymptomatic, but prophylactic ultrasound monitoring is recommended. Ursodeoxycholic acid may reduce stone formation in some patients.
What were the PROMID and CLARINET trials?
PROMID (2009) demonstrated that octreotide LAR significantly extended time to tumor progression versus placebo in patients with midgut neuroendocrine tumors (14.3 vs 6.0 months). CLARINET (2014, using lanreotide depot) confirmed similar antiproliferative benefit across a broader NET population. Together, these landmark trials established somatostatin analogs as standard antiproliferative therapy for well-differentiated gastroenteropancreatic NETs, not just symptomatic treatment.
Are octreotide biosimilars available?
Sandostatin LAR lost US patent protection, and several biosimilar/generic octreotide LAR products have been approved or are in development. The first FDA-approved octreotide LAR alternative (Mycapssa, an oral octreotide capsule) was approved in 2020 for acromegaly — the first oral somatostatin analog. Additional generic LAR depot formulations have been approved internationally. These alternatives are expected to reduce costs, which currently run $2,000–$5,000 per monthly LAR injection.

References

  1. 1
    Placebo-controlled, double-blind, prospective study of octreotide LAR in control of tumor growth in patients with metastatic neuroendocrine midgut tumors (PROMID)(2009)PubMed ↗
  2. 2
    A randomized, double-blind study of octreotide LAR in acromegalic patients(1999)PubMed ↗
  3. 3
    Octreotide in the treatment of carcinoid syndrome: a review of 25 years of clinical experience(2014)PubMed ↗
  4. 4
    Clinical pharmacology and therapeutic use of octreotide(1993)PubMed ↗

Latest Research

Last updated: 2026-02-19