Octreotide: evidence, FDA status and research

It is an injection for a hormone illness called acromegaly and for tumors that cause flushing and diarrhea. Trials, including one of 85 patients, show it lowers hormones and slows tumor growth.

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Octreotide is a workhorse hospital drug for hormone-secreting tumors and acromegaly, not a wellness peptide.

Studies say

Controlled trials show octreotide lowers growth hormone in acromegaly, controls carcinoid symptoms, and slows the growth of midgut neuroendocrine tumors, supporting an A grade for its approved uses.

Why grade A. Octreotide has nearly four decades of use and multiple controlled trials in acromegaly and neuroendocrine tumors behind its label. The trial cited here, PROMID, randomized 85 patients with midgut neuroendocrine tumors and showed a large delay in tumor progression. The label itself documents the symptom-control trials in acromegaly and carcinoid syndrome. ¹²

FDA. Approved. Octreotide is sold as Sandostatin injection for acromegaly, for the flushing and diarrhea of metastatic carcinoid tumors, and for the watery diarrhea of VIP-secreting tumors. Long-acting depot and oral formulations have followed the original 1988 approval. ²

Written from 2 cited sources. Fact-checked 2026-10-27: 15 claims checked, 2 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Acromegaly and hormone-making tumors
Can a US doctor prescribe it?: Yes, FDA approved for acromegaly and symptoms of certain hormone-making tumors.
Properly tested in people?: Yes, in controlled trials, including one of 85 patients.

Evidence checklist

Randomised controlled trial PROMID placebo-controlled; label trialsyes
Human study over 100 people PROMID enrolled 85 patientsno
More than one research group Four decades of trials and registriesyes
Clinical outcomes, not surrogate markers Time to tumor progression doubledyes
Human safety data beyond case reports Decades of use; gallstone and glucose effectsyes

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Octreotide is a lab-made version of somatostatin with eight amino acids. Somatostatin is the body's general-purpose brake on hormone release. The natural form lasts only a couple of minutes in the blood. Researchers engineered octreotide in the 1980s to last for hours. That made it practical as a drug. Novartis sells it as Sandostatin. ²

It is approved for three conditions. The first is acromegaly, where a pituitary tumor makes too much growth hormone. The second is metastatic carcinoid tumors, where hormone release causes flushing and diarrhea. The third is VIPomas, rare pancreatic tumors that cause severe watery diarrhea. Doctors also use it widely off label. Uses include other hormone-secreting tumors, bleeding varices and some kinds of chemotherapy-related diarrhea. ¹²

How it works

Somatostatin receptors sit on the surface of pituitary cells, gut endocrine cells and many neuroendocrine tumor cells. Octreotide binds mainly receptor subtypes 2 and 5. Binding suppresses hormone release. That is why it lowers growth hormone and IGF-1 in acromegaly. It also shuts off the serotonin and peptide release behind carcinoid symptoms. In tumor cells, the same receptors feed into pathways that slow cell division. This is the basis for its effect on tumor growth. ¹²

What human research shows

The PROMID trial tested whether octreotide does more than control symptoms. It randomized 85 patients with well-differentiated metastatic midgut neuroendocrine tumors. They got the long-acting depot form or placebo. Median time to tumor progression was 14.3 months on octreotide and 6 months on placebo. The hazard ratio was 0.34. The benefit held for both functioning and non-functioning tumors. After six months, 66.7% of octreotide patients had stable disease. On placebo, 37.2% did. The interim analysis counted only 16 deaths (7 against 9). That is too few for a firm survival comparison. ¹

In acromegaly, the label reports that octreotide lowers growth hormone and IGF-1 in most patients. It normalizes IGF-1 in a substantial share. Headaches, sweating and joint symptoms ease. In carcinoid syndrome and VIPoma, the label sums up controlled and open studies. They show marked drops in daily flushing episodes and stool frequency. ²

Study	Model	Finding
PROMID (Rinke 2009)	Humans, n=85 with metastatic midgut neuroendocrine tumors, randomized double-blind placebo-controlled	Long-acting octreotide more than doubled median time to tumor progression (14.3 vs 6 months, hazard ratio 0.34). ¹
Sandostatin prescribing information	FDA label summarizing trials in acromegaly, carcinoid syndrome and VIPoma	Documents reductions in growth hormone and IGF-1 in acromegaly and in flushing and diarrhea episodes in hormone-secreting tumors. ²

Safety

The most common side effects affect the gut. They include nausea, belly cramps, loose stools, bloating and poor fat absorption. They are worst early in treatment. Octreotide slows gallbladder emptying. So gallstones or biliary sludge develop in a large share of long-term patients. Octreotide affects insulin and glucagon release, so blood sugar can go either way. It can also slow the heart rate. Thyroid function and vitamin B12 levels may fall with long use. Pain at the injection site is common with the depot form. ²

In PROMID, side effects were reported at similar rates in both arms. Gut complaints and fatigue were the most frequent. Blood effects were rare. ¹

Questions for your clinician

Should I have gallbladder imaging while on long-term octreotide?
Is octreotide or lanreotide a better fit for my tumor?
How will my blood sugar and thyroid be checked?

Questions people ask

Does octreotide shrink tumors?

It mostly stabilizes them. PROMID showed a large delay in progression in midgut neuroendocrine tumors. But tumors rarely shrank in either arm. In acromegaly, pituitary tumors shrink modestly in some patients. ¹²

Why does octreotide cause gallstones?

Somatostatin receptors on the gallbladder slow its contraction. Bile then sits longer and forms crystals. Gallstones or sludge appear in a large share of long-term users. Most cause no symptoms. The label advises periodic ultrasound checks. ²

What is the difference between octreotide and lanreotide?

Both are lab-made versions of somatostatin. They have similar receptor profiles and the same core approved uses. Lanreotide comes as a deep injection under the skin, given monthly. Octreotide comes as a short-acting injection, a monthly depot into the muscle and an oral capsule. ²

Is octreotide used for weight loss or anti-aging?

No. It suppresses growth hormone. That is the opposite of what the anti-aging peptide market usually wants. Its effects on blood sugar and digestion make it a poor general supplement. It is used for hormone-secreting tumors and acromegaly. ²

Citations

Rinke 2009, J Clin Oncol: placebo-controlled trial of octreotide LAR in metastatic midgut neuroendocrine tumors (PROMID) doi.org
Novartis: Sandostatin (octreotide acetate) injection prescribing information novartis.com