Octreotide (Sandostatin): How the Somatostatin Copy Works
Octreotide is a lab-made copy of somatostatin, the hormone that holds back growth hormone, and it has been a US prescription drug since 1988, first sold as Sandostatin. It is approved for acromegaly, a disease of too much growth hormone, and for the diarrhea and flushing caused by two kinds of hormone-making tumors.
Somatostatin works like an off switch. The natural hormone is a chain of 14 amino acids and is half gone from the blood in 1 to 3 minutes. Octreotide keeps just 8 units, flips two of them into mirror images, and locks the chain into a ring. Its label puts its half-life at about 1.7 to 1.9 hours. It is not a GLP-1 drug and has no US weight-loss use.
Key facts
What it copies: Somatostatin, a 14-unit hormone that holds back growth hormone, insulin, glucagon and several gut signals.
How it was rebuilt: Cut to 8 units, two of them mirror-image D forms, closed into a ring by a sulfur link between units 2 and 7.
Why it lasts: Half of it is gone in about 1.7 to 1.9 hours, against 1 to 3 minutes for the natural hormone.
What it binds: Mostly somatostatin receptor 2, with a moderate hold on receptors 3 and 5.
Status on 9 November 2026: A US prescription drug since 1988 for acromegaly, carcinoid tumor symptoms and VIPoma diarrhea, as Sandostatin, Sandostatin LAR Depot and other forms.
Sources: Sandostatin label on DailyMed, revised July 2024; IUPHAR somatostatin receptor review, 2018; Drugs@FDA record, NDA 019667
What is octreotide?
Octreotide is a somatostatin analogue. That means a lab-made drug built to act like the natural hormone somatostatin. Its FDA label calls it a long-acting octapeptide. Octa means eight. A peptide is a short chain of amino acids, the building blocks of proteins.
The label adds that octreotide holds back growth hormone, glucagon and insulin even more strongly than somatostatin does. It also cuts the release of gut signals such as serotonin, gastrin and VIP, plus secretin, motilin and pancreatic polypeptide. And it lowers blood flow to the gut organs. A 2018 review says it was the first somatostatin copy approved for use in patients.
Molecule Mechanics pictures receptors as locks and drugs as keys. Most of the series so far has covered keys for appetite and blood sugar locks. One example is our animated tirzepatide explainer. Octreotide is a different kind of key. It belongs to the somatostatin family, not the GLP-1 family, and its job is to turn signals down.
Sources: Sandostatin label on DailyMed, revised July 2024; IUPHAR somatostatin receptor review, 2018
What is somatostatin, the hormone octreotide copies?
Somatostatin is the body's own brake on growth hormone. In 1973, a team in Roger Guillemin's lab reported a peptide from the sheep hypothalamus, a part of the brain. It stopped cells from releasing growth hormone. They worked out its order of 14 amino acids and showed that a lab-made copy worked too.
In 1977, Guillemin and Andrew Schally shared half of the Nobel Prize in Physiology or Medicine. It honored their work on the peptide hormones made by the brain. The prize press release singled out somatostatin as the first known inhibitor of pituitary function.
The problem with the real thing. Natural somatostatin is cleared from the blood within minutes. The 2018 review puts its half-life under 3 minutes. It says that short life limits it as a medicine. So chemists set out to build a copy that would hold up longer.
The opposite switch. Somatostatin has a partner that pushes the other way: GHRH, a hormone from the hypothalamus that switches growth hormone release on. Tesamorelin, sold as Egrifta SV, is a lab-made GHRH analogue. Our tesamorelin calculator covers the vial math for that peptide.
Sources: Brazeau and colleagues, Science 1973; Nobel Prize press release, 1977; IUPHAR somatostatin receptor review, 2018; Egrifta SV label via openFDA
How was octreotide made to last?
Octreotide was made to last by shrinking the hormone, then protecting what was left. In 1982, a paper with W. Bauer as first author described a compound coded SMS 201-995. They started from a stiffened copy of the small piece of somatostatin thought to do the work. Then they changed it step by step. The result had 8 units. It later became octreotide.
| Position | Unit | Note |
|---|---|---|
| 1 | D-phenylalanine | Mirror-image form |
| 2 | Cysteine | One end of the sulfur ring |
| 3 | Phenylalanine | Normal form |
| 4 | D-tryptophan | Mirror-image form |
| 5 | Lysine | Normal form |
| 6 | Threonine | Normal form |
| 7 | Cysteine | Other end of the sulfur ring |
| 8 | Threoninol | An alcohol version of threonine, not a standard amino acid |
Mirror-image units. Amino acids come in two shapes that are mirror images, like a left and a right glove. The body builds proteins from the L form. Octreotide puts the D form at positions 1 and 4. The idea had been tried before. In 1975, a team swapped the tryptophan in somatostatin for its D form. They reported a version more potent than the natural hormone.
The ring. The two cysteines at positions 2 and 7 each carry a sulfur atom. The sulfurs bond to each other and close the chain into a loop. That is why the label calls octreotide a cyclic octapeptide.
What the changes did. In test tubes, SMS 201-995 held up well against pure enzymes and tissue extracts that break peptides apart. In rats and rhesus monkeys it was at least 20 times more active than somatostatin, depending on the test. It also acted much longer. Our sources report these results. They do not spell out why the mirror units and the ring protect it.
In people. The Sandostatin label gives octreotide a half-life of 1.7 to 1.9 hours, against 1 to 3 minutes for natural somatostatin. Its molecular weight is 1019.3 grams per mole.
Sources: Bauer and colleagues, Life Sciences 1982; Rivier, Brown and Vale, 1975; Sandostatin label on DailyMed, revised July 2024
Which receptors does octreotide bind?
Octreotide binds mostly somatostatin receptor 2. Somatostatin itself works through five receptors, named SST1 to SST5. It fits all five well. A 1999 review found that short lab-made copies such as octreotide bind well to only three of them: 2, 3 and 5.
| Receptor | Binding value (nM) | In plain words |
|---|---|---|
| SST1 | Above 1,000 | Barely binds |
| SST2 | 0.4 | Strong, its main target |
| SST3 | 4.4 | Moderate |
| SST4 | Above 1,000 | Barely binds |
| SST5 | 5.6 | Moderate |
Why the pattern matters. Different jobs lean on different receptors. The 1999 review links growth hormone release to receptors 2 and 5. It links insulin release to receptor 5 and glucagon release to receptor 2. Since octreotide grips receptor 2 hardest, it hits growth hormone harder than insulin. The 2018 review adds that its moderate hold on receptor 5 does not translate into much effect.
The rat numbers. A 1986 paper by several of the same authors measured this in rats. Compared with somatostatin, the compound blocked growth hormone 70 times more strongly. It blocked insulin 3 times more and glucagon 23 times more. That gap is what the papers mean by selective. These are animal results.
Growth hormone is also made as a medicine in its own right, called somatropin. Our HGH calculator converts its units. Octreotide sits on the other side of that system, as a brake.
Sources: Patel, receptor family review, 1999; IUPHAR somatostatin receptor review, 2018; Pless and colleagues, 1986 rat study; Sandostatin label on DailyMed, revised July 2024
What is octreotide used for?
The US Sandostatin label lists three uses. All three are cases where the body or a tumor makes too much of a hormone signal.
- Acromegaly: a condition of too much growth hormone, usually from a pituitary tumor. Octreotide is approved to lower growth hormone and IGF-1. That applies when surgery, pituitary radiation and bromocriptine did not work well enough or cannot be used. IGF-1 is the growth factor that growth hormone drives.
- Carcinoid tumors that have spread: it is approved to treat the severe diarrhea and flushing that come with them.
- VIPomas: tumors that release VIP, a gut signal. Octreotide is approved for the heavy, watery diarrhea they cause.
A limit the label states plainly. The Sandostatin trials did not show better signs and symptoms, smaller tumors or slower tumor growth. The label adds that those trials were not built well to detect such effects. So its approved role is to ease symptoms and lower hormone levels. It is not a tumor treatment.
Any treatment choice for these conditions belongs to a specialist. This page only reports what the label says.
What is the difference between Sandostatin and Sandostatin LAR?
Sandostatin and Sandostatin LAR Depot hold the same drug, octreotide acetate. They release it at different speeds. Sandostatin is the short-acting liquid approved in 1988. Sandostatin LAR Depot was approved on 25 November 1998 as a new form of the drug. It holds the drug inside tiny beads called microspheres. The beads are made of a biodegradable polymer and let the drug out slowly.
The LAR label covers the same three uses, but only for people in whom regular Sandostatin has already worked and been tolerated. Its third acromegaly trial had 122 people who received the full course. Of them, 57% kept average growth hormone under the trial's target, with a normal average IGF-1. These were people who had already responded to octreotide.
| Brand | Form | First US approval | Approved for |
|---|---|---|---|
| Sandostatin | Short-acting liquid | 21 October 1988 | Acromegaly, carcinoid tumor symptoms, VIPoma diarrhea |
| Sandostatin LAR Depot | Long-acting version held in tiny biodegradable beads | 25 November 1998 | The same three uses, for people who already did well on Sandostatin |
| Mycapssa | Delayed-release capsule taken by mouth | 26 June 2020 | Long-term upkeep in acromegaly only, after a good response to octreotide or lanreotide |
We name forms and approvals here, not how any of them is given.
Sources: Drugs@FDA record, NDA 019667; Drugs@FDA record, NDA 021008; Sandostatin LAR Depot label on DailyMed
What is Mycapssa, the octreotide capsule?
Mycapssa is octreotide in a delayed-release capsule taken by mouth. The FDA approved it on 26 June 2020, and Chiesi now holds it. It has one approved use: keeping acromegaly in check over the long term. That is for people who already responded to and tolerated octreotide or lanreotide. It is not approved for carcinoid tumors or VIPomas.
How a peptide gets through. The Mycapssa label describes a study of the gaps between the cells that line the gut. Those gaps opened wider about 2 hours after a capsule and were back to normal by 5.5 hours. The label calls the effect completely reversible.
The trial. The main study, called OPTIMAL, ran for 9 months. It enrolled 56 people whose acromegaly was already controlled on other somatostatin drugs. It was randomized and double-blind, against a dummy capsule. By the end, 58% on Mycapssa kept IGF-1 at or below the upper normal limit. On placebo, 19% did. The label also notes that 25% on Mycapssa had to switch back to another somatostatin drug during the study. These are group results, not a promise for any one person.
Mycapssa is not the only peptide pill. The Wegovy pill gets semaglutide through the stomach with a helper called SNAC instead, as our oral semaglutide episode shows.
Sources: Mycapssa label on DailyMed; Drugs@FDA record, NDA 208232; ClinicalTrials.gov NCT03252353
What are the side effects of octreotide?
The side effects of octreotide mostly follow from what it switches off. The Sandostatin label lists six warnings, and the numbers below come from its trial data.
- Gallbladder: octreotide slows how hard the gallbladder squeezes and cuts bile release. In trials, mostly of people with acromegaly or psoriasis, 63% had bile tract changes. That was 27% with gallstones, 24% with sludge but no stones and 12% with a widened bile duct. Among people treated for a year or more, 52% had stones or sludge. The label also lists inflamed gallbladder, blocked bile ducts and pancreatitis among reported problems.
- Heart: in acromegaly, 25% developed a slow heart rate under 50 beats a minute. Another 10% had changes in how heart signals travel, and 9% had rhythm problems.
- Blood sugar: it shifts the balance between insulin, glucagon and growth hormone. So blood sugar can go either way. In acromegaly, 16% had high blood sugar and 3% low.
- Thyroid: it turns down TSH, the pituitary signal that drives the thyroid. In acromegaly, 12% had low thyroid function on blood tests alone and 8% developed goiter.
- Gut: diarrhea, loose stools, nausea and belly discomfort were each seen in 34% to 61% of acromegaly patients in US studies. Of those patients, 2.6% stopped because of them. In people with carcinoid tumors or VIPomas the same complaints were far less common.
- Fat and vitamin B12: a warning added in July 2024 says somatostatin drugs can cut the flow of pancreas enzymes and bile acids. That can cause fatty stools, bloating and weight loss. The label also warns about changes in vitamin B12 levels.
The only contraindication on the label is sensitivity to the drug or anything in it. Only a treating doctor can judge how these risks apply to one person.
Sources: Sandostatin label on DailyMed, revised July 2024; Mycapssa label on DailyMed
Is octreotide still FDA approved?
Yes. On 9 November 2026, Drugs@FDA listed Sandostatin (NDA 019667, Novartis) as a prescription drug. The FDA first approved it on 21 October 1988, as a new molecular entity with priority review. Sandostatin LAR Depot and Mycapssa were also listed as prescription drugs.
Two strengths were dropped. Drugs@FDA marks two older Sandostatin strengths as discontinued. A Federal Register notice of 2 June 2021 explains why. Novartis told the FDA it was stopping them, in a letter received on 11 May 2020. After a citizen petition, the FDA ruled that the drop had nothing to do with safety or with how well they worked.
No withdrawal notice found. We searched the Federal Register on 9 November 2026. Searches for the Sandostatin LAR and Mycapssa applications returned nothing. The Sandostatin results held no notice withdrawing approval. A prescription listing shows approval, though, not that a product is in stock in any one place.
Status lines like these are checked straight against FDA and Federal Register records, as set out in our medical review policy.
Sources: Drugs@FDA record, NDA 019667; Federal Register notice of 2 June 2021; Drugs@FDA record, NDA 021008; Drugs@FDA record, NDA 208232
How does octreotide compare with other hormone copies made to last?
Octreotide solved the short-life problem by cutting the hormone down and armoring it. Many newer peptide drugs do the opposite and add parts. Semaglutide, for example, carries a fatty side chain that grips albumin in the blood. The Wegovy label puts its half-life at about 1 week.
Cagrilintide, an experimental copy of the hormone amylin, also uses a fatty tail to stay in the blood. See our cagrilintide page for how. Foundayo skips peptides and uses a small molecule instead. It is covered in our Foundayo explainer.
Each of these drugs solves the same short-life problem in its own way, and octreotide is the oldest of them in US use.
Sources: Wegovy label via openFDA; Molecule Mechanics channel
What else do people ask about octreotide?
What is octreotide?+
Octreotide is a prescription drug that copies somatostatin, a natural hormone that holds back growth hormone and several gut signals. It is a ring-shaped chain of 8 units, much shorter than the 14-unit hormone. It lasts far longer in the blood. In the US it was first approved in 1988 as Sandostatin.
How does octreotide work?+
It binds the same receptors that somatostatin uses, mostly receptor type 2. When it does, cells release less growth hormone. The gut and some tumors also release less of signals such as serotonin and VIP. In people with acromegaly, the label says it substantially lowers growth hormone, IGF-1, or both.
What is octreotide acetate used for?+
Octreotide acetate is the form of octreotide in Sandostatin and its other US brands. The US label lists three uses: lowering growth hormone and IGF-1 in acromegaly, easing the severe diarrhea and flushing of carcinoid tumors that have spread, and treating the watery diarrhea caused by VIPomas.
What is Sandostatin?+
Sandostatin is the Novartis brand name for octreotide acetate. The FDA approved it on 21 October 1988 as a new molecular entity. Drugs@FDA still listed it as a prescription drug on 9 November 2026.
What is the generic name for octreotide?+
Octreotide is the generic name. The labels name the active form octreotide acetate. Sandostatin and Sandostatin LAR Depot are the Novartis brand names, and Mycapssa is the capsule brand held by Chiesi.
What is the relationship between octreotide and somatostatin?+
Octreotide is a lab-made copy of somatostatin. It keeps 8 of the 14 units of the hormone, closed into a ring, acts on the same receptors, and lasts about 1.7 to 1.9 hours in the blood instead of 1 to 3 minutes. The label says it holds back growth hormone, glucagon and insulin even more strongly than somatostatin.
What is somatostatin?+
Somatostatin is a natural peptide hormone of 14 amino acids. It was found in 1973 in sheep brain tissue as a blocker of growth hormone release. The 1977 Nobel press release called it the first known inhibitor of pituitary function. In the blood it is half gone in 1 to 3 minutes. That is why drug makers built longer-lasting copies such as octreotide.
What is octreotide used for in acromegaly?+
Acromegaly happens when the body makes too much growth hormone, usually because of a pituitary tumor. The US label approves octreotide to lower growth hormone and IGF-1 in acromegaly. It is for people who did not do well enough with surgery, pituitary radiation and bromocriptine, or who cannot have them.
What is Sandostatin LAR?+
Sandostatin LAR Depot is the long-acting form of octreotide. The drug sits inside tiny beads made of a polymer that breaks down in the body. The beads let it out slowly. The FDA approved it in 1998. Its label covers the same three uses, but only for people who already did well on regular Sandostatin.
What is Mycapssa?+
Mycapssa is octreotide in a delayed-release capsule, approved by the FDA on 26 June 2020. It is approved only to keep acromegaly in check over the long term. It is for people who already did well on octreotide or lanreotide. Its label says it briefly makes the gut lining easier to cross, an effect that was gone within hours.
What are the side effects of octreotide?+
The label's biggest warnings are gallbladder problems, a slow or uneven heartbeat, high or low blood sugar, and low thyroid function. In trials, 27% of patients developed gallstones. Diarrhea, loose stools, nausea and belly discomfort were common in acromegaly studies. Newer label warnings cover fat malabsorption and low vitamin B12.
Is octreotide chemotherapy or immunotherapy?+
Neither. Octreotide is a hormone copy, not a drug that kills cancer cells or one that works through the immune system. Its US label approves it to ease the diarrhea and flushing of spread carcinoid tumors and the watery diarrhea of VIPomas. The label says its trials did not show tumors shrinking or growing more slowly.
Is octreotide a GLP-1 drug?+
No. Semaglutide and the other GLP-1 drugs mimic another gut hormone, GLP-1, through its own receptor. Octreotide mimics somatostatin and works through somatostatin receptors. Its US label lists no weight-loss use.
What is the use of octreotide in pancreatitis?+
Pancreatitis is not one of octreotide's approved US uses. In fact, the Sandostatin label lists pancreatitis among the problems reported during treatment, next to its gallbladder warnings. This page covers only the uses the US label approves.
Is octreotide discontinued?+
No. On 9 November 2026, Drugs@FDA listed Sandostatin, Sandostatin LAR Depot and Mycapssa as prescription drugs. Two older Sandostatin strengths were discontinued in 2020. In 2021 the FDA found that this was not for safety or effectiveness reasons.
Sources: Sandostatin label on DailyMed, revised July 2024; Drugs@FDA record, NDA 019667; Sandostatin LAR Depot label on DailyMed; Mycapssa label on DailyMed; Brazeau and colleagues, Science 1973; Nobel Prize press release, 1977; IUPHAR somatostatin receptor review, 2018; Federal Register notice of 2 June 2021
What did we learn about octreotide?
Octreotide is the body's growth hormone brake, rebuilt to survive. Chemists kept 8 of somatostatin's 14 units. They flipped two into mirror images and tied the chain into a ring. That stretched its life in the blood from minutes to hours. Shrinking it also narrowed its reach to mostly one receptor, number 2. That is why it presses on growth hormone far more than on insulin.
The Molecule Mechanics channel turns peptide drug science into short animations, each with its own source list. It teaches; it does not recommend treatments. The narrator is an AI voice built with ElevenLabs, and the artwork is original. Before octreotide, the series looked at Foundayo, oral semaglutide, cagrilintide and, first of all, tirzepatide.
Readers also ask about retatrutide, a Lilly weight drug that is still in trials. Our retatrutide calculator led all our pages in Google clicks over the last 28 days. Spotted an error here? Our corrections policy explains how to report it.
Visit the Molecule Mechanics channel
Sources: Molecule Mechanics channel
Education only, not medical advice. This page draws on FDA labels, FDA records, the Federal Register and published studies of octreotide (Sandostatin). Whether a prescription medicine fits someone is for that person and their own doctor to decide.