Overview

Octreotide is a synthetic octapeptide analog of somatostatin with markedly extended half-life (~2 hours IV vs 1-3 minutes for native somatostatin). FDA-approved for acromegaly (excess GH) and symptomatic treatment of metastatic carcinoid tumors and VIPomas, it is one of the most clinically important peptide drugs in medicine. It mimics the inhibitory effects of endogenous somatostatin on growth hormone, glucagon, and gastrointestinal hormones while also causing vascular smooth muscle contraction to reduce splanchnic blood flow.

Mechanism of Action

Octreotide binds somatostatin receptors (primarily SSTR2 and SSTR5), which are GPCRs coupled to inhibitory G-proteins. Activation inhibits adenylyl cyclase (reducing cAMP), stimulates phospholipase C via beta-gamma G-protein subunits, leads to calcium channel inhibition and K+ channel activation, ultimately suppressing GH, IGF-1, insulin, glucagon, and various gastrointestinal hormones. In neuroendocrine tumors, SSTR2 binding drives CDKN1B (p27) upregulation inhibiting cell proliferation. Also stimulates neuronal migration and axon outgrowth.

Potential Benefits

  • FDA-approved for acromegaly (GH excess) management
  • FDA-approved for carcinoid tumor flushing and diarrhea
  • FDA-approved for VIPoma-associated diarrhea
  • Reduces splanchnic blood flow for GI bleeding
  • Long-acting depot formulation (Sandostatin LAR) for monthly dosing
  • Antiproliferative effects in neuroendocrine tumors
  • Neuroprotective potential via neuronal migration effects

Dosage Protocols

The following reflects doses used in published research studies. This is not medical advice. Consult a qualified healthcare professional.

Beginner50 mcg SC 3x daily (titrate from lower dose)
Intermediate100 mcg SC 3x daily
Advanced500 mcg SC 3x daily or 30-40 mg IM monthly
Cycle DurationChronic use for acromegaly, carcinoid, VIPoma

FDA-approved as Sandostatin. Taper when discontinuing to avoid rebound.

Routes of Administration

Subcutaneous Injection ~100%

Immediate-release formulation. Rotate injection sites.

Intramuscular Injection (LAR depot) Sustained release over 4 weeks

Sandostatin LAR depot administered monthly by clinician.

Intravenous 100%

Used for acute variceal bleeding.

Stacking Protocols

Popular research stacks involving Octreotide:

Acromegaly Combination

Clinical combination for GH-secreting adenomas not fully controlled by monotherapy.

OctreotidePegvisomant

Reconstitution

StorageRefrigerate at 2-8°C. Solution can be kept at room temperature ≤25°C for up to 14 days.

FDA-approved pharmaceutical. Follow manufacturer's reconstitution for LAR depot.

Need exact syringe measurements?

Amino Acid Sequence

D-Phe-cyclo[Cys-Phe-D-Trp-Lys-Thr-Cys]-Thr-ol (disulfide bridge Cys2-Cys7)

Side Effects & Safety

  • GI symptoms: nausea, diarrhea, abdominal cramping, steatorrhea
  • Cholelithiasis (gallstone formation) with long-term use
  • Bradycardia
  • Hypoglycemia or hyperglycemia
  • Injection site pain
  • Hypothyroidism with prolonged use

Safety & Contraindications

This information is for educational purposes only. Consult a qualified healthcare provider before using any peptide.

Relative

Pregnancy / Lactation

Relative

Bleeding Disorders

Absolute

Active Skin Infection at Injection Site

Drug Interactions

  • Cyclosporine:

FDA Safety Information

FDA labeling warns of gallbladder abnormalities, cardiac conduction abnormalities, hyper-/hypoglycemia, hypothyroidism, and pancreatitis.

FDA Source: Bulk Drug Substances Safety Risks

Pharmacokinetics

Half-Life~1.5 hours (SC); LAR depot sustained release over 4 weeks
StorageRefrigerate ampoules/vials at 2-8°C. Do not freeze. Protect from light.

Synergistic Compounds

The following compounds have been studied alongside Octreotide for potential complementary or synergistic effects:

LanreotidePasireotideInterferon-alpha

Learn More

References & Further Reading

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