Octreotide
The somatostatin analogue that made the hormone usable, with a half-life about sixty times longer
Octreotide is a ring of eight amino acids that copies the active part of somatostatin, the hormone that switches off growth hormone and many gut hormones. Approved as Sandostatin in 1988, now also as a monthly depot, an oral capsule and a pen, it controls acromegaly and the diarrhoea of hormone-secreting gut tumours, and in the PROMID trial it more than doubled the time before midgut tumours grew.
What is it?
Somatostatin is the body's general off-switch for hormones: it suppresses growth hormone from the pituitary and insulin, glucagon and many gut hormones. As a drug it is nearly useless, because it disappears from the blood in 1 to 3 minutes. Octreotide keeps the active region in a shorter, more stable ring of eight amino acids. The Sandostatin label gives its half-life as 1.7 to 1.9 hours, with a peak about 0.4 hours after a 100 microgram injection, and it binds mainly the SSTR2 and SSTR5 somatostatin receptors.
Sandostatin injection was approved on October 21, 1988 (NDA 019667), the monthly depot Sandostatin LAR in 1998, the oral capsule Mycapssa in 2020 and the Bynfezia Pen in 2024. The injection's label covers three uses: acromegaly where surgery, radiation and bromocriptine have not worked; the severe diarrhoea and flushing of metastatic carcinoid tumours; and the watery diarrhoea of VIP-secreting tumours. In acromegaly it starts at 50 micrograms three times a day and is adjusted to growth hormone or IGF-1 levels; the label notes that doses above 300 micrograms a day seldom add benefit.
Its strongest tumour result came from PROMID. In a placebo-controlled trial in metastatic midgut neuroendocrine tumours, the monthly depot lengthened median time to progression from 6 to 14.3 months (hazard ratio 0.34), and stable disease at six months was 66.7% against 37.2%. Long-term follow-up found no survival difference (84.7 against 83.7 months), but most placebo patients had crossed over to octreotide, which the authors say may have hidden one.
For acromegaly, the question has become whether patients can take it by mouth. In the MPOWERED trial, 92 patients already controlled on injections were randomised to oral octreotide capsules or to continue injectable somatostatin analogues: 91% on capsules and 100% on injections kept their biochemical response, which met the trial's non-inferiority margin. Treating patients before surgery is less clear: a randomised trial found 38% of large tumours cured after pretreatment against 24% with direct surgery, a difference that was not significant.
In bleeding from swollen veins in the gullet of people with cirrhosis, octreotide is given alongside endoscopic treatment. A trial in which it was added to sclerotherapy for 48 hours found no difference in seven-day death or rebleeding against placebo. A 2026 Thai trial in 220 patients after band ligation found one day of octreotide infusion as good as the standard five days at preventing early rebleeding, with fewer transfusions and shorter stays.
The rest of its record is mixed. It reduced transfusions in bleeding from abnormal gut blood vessels (the OCEAN trial), missed its primary endpoint in malignant bowel obstruction, and matched intravenous somatostatin, not beaten it, in preventing pancreatic fistulas after surgery.
Its side effects follow from what it switches off. The label lists gallbladder problems, slow heart rate, diarrhoea, nausea, abdominal discomfort, high blood sugar and an underactive thyroid among the most common in acromegaly. Blood sugar can go too high or too low, gallstones need periodic checks, and complete heart block has been reported after intravenous use, mostly at higher-than-recommended doses or continuous infusion.
Mechanism of Action
Octreotide activates somatostatin receptors, mainly SSTR2 and SSTR5, and so suppresses the hormones they control: growth hormone, insulin, glucagon and gut hormones.
Pituitary: growth hormone
On pituitary cells it lowers growth hormone and, downstream, IGF-1, which is how it treats acromegaly; doses are titrated to those two levels (label).
Gut and pancreas hormones
It suppresses hormone secretion from neuroendocrine tumours, reducing the diarrhoea and flushing of carcinoid tumours and the watery diarrhoea of VIPomas, and it inhibits insulin and glucagon, which is why blood sugar can move either way (label).
Slower tumour growth
In PROMID the monthly depot slowed progression of metastatic midgut tumours; the injection's label says its own trials did not show tumour shrinkage or slower growth, but were not designed to detect them.
Heart and gallbladder
The label warns of slow heart rate and conduction problems, including complete heart block after intravenous use, and of gallstones and their complications.
Published Research
The studies behind octreotide, read from their PubMed abstracts: tumour control, acromegaly, variceal bleeding and the uses where it did not help.
PROMID: midgut tumours, octreotide LAR against placebo
Median time to tumour progression was 14.3 months on octreotide LAR against 6 on placebo (hazard ratio 0.34); stable disease at six months was 66.7% against 37.2%. With few deaths, the survival analysis was not confirmatory.
MPOWERED: oral capsules against injections in acromegaly
92 patients controlled on injectable somatostatin analogues were randomised to oral octreotide (55) or to continue injections (37). Response was maintained in 91% against 100%, meeting the non-inferiority margin; treatment-related adverse events, mostly gastrointestinal, occurred in 35% against 41%.
Variceal bleeding: one day against five days of infusion
In 220 patients after endoscopic band ligation, 5-day rebleeding was 1.83% against 1.80%, 6-week rebleeding 8.26% against 10.81% and 6-week mortality 5.50% against 6.31%; the one-day group needed fewer transfusions and left hospital sooner.
Variceal bleeding: added to sclerotherapy, 68 patients
48 hours of intravenous octreotide after sclerotherapy did not change 7-day mortality (20% against 17.9% on placebo), rebleeding (20% against 21.4%) or transfusions.
Before acromegaly surgery: long-term results
Large adenomas were cured in 38% after somatostatin-analogue pretreatment against 24% with direct surgery at one year (P=0.27), and 41% against 27% at five years; a meta-analysis with other trials showed a non-significant trend.
Fewer transfusions in gut vascular bleeding
In the OCEAN trial in angiodysplasia-related anaemia, octreotide cut the mean number of transfusion units by 10.2 against standard care (about 11 against 21 units) and reduced endoscopic procedures by 0.9 a year.
It missed its endpoint in bowel obstruction
In a double-blind trial in advanced cancer with inoperable bowel obstruction, 17 people on octreotide and 14 on placebo were free of vomiting for 72 hours (p = 0.67). An adjusted analysis showed fewer vomiting episodes, which the authors call grounds for further study rather than a result.
No better than somatostatin after pancreatic surgery
In the PREFIPS randomised trial in 651 patients, serious pancreatic fistula occurred in 23.5% overall, with no difference between continuous intravenous somatostatin (24.1%) and subcutaneous octreotide (22.9%).
Carcinoid survival unchanged
Long-term follow-up of the placebo-controlled PROMID trial found median overall survival of 84.7 months on octreotide LAR and 83.7 on placebo, a hazard ratio of 0.83 that was not significant.
Dosing Data
Sandostatin injection is given under the skin (or intravenously) in divided doses, adjusted to hormone levels or symptoms; the depot is monthly and the capsules are daily.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Side Effects & Contraindications
Reported Side Effects
From the trials above and the Sandostatin prescribing information (DailyMed set 4e2c9856, version 23, effective July 22, 2026).
Contraindications & Cautions
From the label.
Legal Status
An approved drug with four US products.
Frequently Asked Questions
?What is octreotide used for?
Acromegaly where surgery, radiation and bromocriptine have not worked, the diarrhoea and flushing of metastatic carcinoid tumours, and the watery diarrhoea of VIPomas.
?How is it different from somatostatin?
It keeps the active part of the hormone in a more stable ring. Natural somatostatin lasts 1 to 3 minutes in blood; the Sandostatin label gives octreotide's half-life as 1.7 to 1.9 hours.
?Can it be taken by mouth?
Yes, as Mycapssa, approved in 2020. The original product is injected.
?What are the common side effects?
The label lists gallbladder abnormalities, slow heart rate, diarrhoea, nausea, abdominal discomfort, high blood sugar and underactive thyroid, each over 10% in acromegaly.
?Does it shrink or slow tumours?
In the PROMID trial the monthly depot more than doubled median time to progression in midgut neuroendocrine tumours (14.3 against 6 months); long-term survival was similar, with most placebo patients later switching to octreotide.
?Can the capsules replace injections in acromegaly?
For patients already controlled on injections, the MPOWERED trial found 91% kept control on oral capsules against 100% on injections, within the trial's non-inferiority margin.
?What does it interact with?
The label names cyclosporine (lower levels, risk of rejection), insulin and diabetes tablets (dose changes), bromocriptine (higher levels) and heart-slowing drugs such as beta-blockers, and says to stop it at least 24 hours before each lutetium Lu 177 dotatate dose.
?Why is it used in variceal bleeding?
It is given alongside endoscopic treatment for bleeding varices in cirrhosis. Added to sclerotherapy it did not change death or rebleeding in a 68-patient trial, and a 2026 trial found one day of infusion as good as five after band ligation.
References
- [fda-pi] Sandostatin (octreotide acetate) injection prescribing information, sections 2, 5, 6 and 12.3 (DailyMed SPL version 23, effective July 22, 2026; read October 1, 2026).
- [pubmed] Rinke A, et al. "Placebo-controlled, double-blind, prospective, randomized study on the effect of octreotide LAR in the control of tumor growth in patients with metastatic neuroendocrine midgut tumors: a report from the PROMID Study Group." J Clin Oncol, 2009;27(28):4656-63. PMID: 19704057.
- [pubmed] Fleseriu M, et al. "Maintenance of response to oral octreotide compared with injectable somatostatin receptor ligands in patients with acromegaly: a phase 3, multicentre, randomised controlled trial." Lancet Diabetes Endocrinol, 2022;10(2):102-111. PMID: 34953531.
- [pubmed] Chirapongsathorn S, et al. "One vs Five Days of Octreotide Infusion for Acute Esophageal Variceal Bleeding: A Randomized Controlled Trial." Am J Gastroenterol, 2026;121(8):1885-1894. PMID: 41090987.
- [pubmed] Morales GF, et al. "Octreotide for esophageal variceal bleeding treated with endoscopic sclerotherapy: a randomized, placebo-controlled trial." Hepatogastroenterology, 2007;54(73):195-200. PMID: 17419259.
- [pubmed] Fougner SL, et al. "Preoperative octreotide treatment of acromegaly: long-term results of a randomised controlled trial." Eur J Endocrinol, 2014;171(2):229-35. PMID: 24866574.
- [pubmed] Goltstein LCMJ, et al. "Standard of Care Versus Octreotide in Angiodysplasia-Related Bleeding (the OCEAN Study): A Multicenter Randomized Controlled Trial." Gastroenterology, 2024;166(4):690-703. PMID: 38158089.
- [pubmed] Currow DC, et al. "Double-blind, placebo-controlled, randomized trial of octreotide in malignant bowel obstruction." J Pain Symptom Manage, 2015;49(5):814-21. PMID: 25462210.
- [pubmed] Gaujoux S, et al. "Somatostatin Versus Octreotide for Prevention of Postoperative Pancreatic Fistula: The PREFIPS Randomized Clinical Trial: A FRENCH 007-ACHBT Study." Ann Surg, 2024;280(2):179-187. PMID: 38662619.
- [pubmed] Rinke A, et al. "Placebo-Controlled, Double-Blind, Prospective, Randomized Study on the Effect of Octreotide LAR in the Control of Tumor Growth in Patients with Metastatic Neuroendocrine Midgut Tumors (PROMID): Results of Long-Term Survival." Neuroendocrinology, 2017;104(1):26-32. PMID: 26731483.
- [pubmed] Fan M, et al. "Octreotide and Octreotide-derived delivery systems." J Drug Target, 2023;31(6):569-584. PMID: 37211679.
- [pubmed] Cavallin M, et al. "Terlipressin plus albumin versus midodrine and octreotide plus albumin in the treatment of hepatorenal syndrome: A randomized trial." Hepatology, 2015;62(2):567-74. PMID: 25644760.
Sources & Citations
Studies were read from their PubMed records (October 5, 2026); the label and Drugs@FDA are listed below with their read dates.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Talk to a licensed clinician about your own situation.