Pentagastrin
A gastrin mimic used to provoke acid and calcitonin for testing
Pentagastrin is a synthetic five-amino-acid analogue of gastrin. Approved in the US as Peptavlon in 1974 and now discontinued, it was used to measure stomach acid output and, by provoking calcitonin release, to detect medullary thyroid carcinoma and C-cell hyperplasia.
What is it?
Pentagastrin mimics the active end of the hormone gastrin. For decades it was a standard diagnostic agent: given by injection, it stimulates the stomach to secrete acid, which let doctors measure maximal acid output, and it was used as a pharmacological stimulus in studies of acid-suppressing drugs.
Its second use was in thyroid cancer screening. Medullary thyroid carcinoma arises from calcitonin-producing C cells, and a pentagastrin injection provokes a calcitonin surge that can unmask small tumours. In a 1978 family study, seven people showed a rise only after pentagastrin, and some were later found at surgery to have focal carcinoma or C-cell hyperplasia; a later study proposed a stimulated calcitonin cut-off of 275 ng/l to separate carcinoma from hyperplasia.
Its limits became clear: in families with MEN 2A, 15.4% of non-carriers had false-positive pentagastrin tests, and genetic RET testing is now the first-line screen. In the US the product is discontinued. Psychiatric researchers also used it as a challenge agent, because acting on cholecystokinin-B receptors in the brain it can provoke panic-like reactions.
At a Glance
Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.
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Published Research
Studies of pentagastrin, from their PubMed abstracts.
Calcium vs pentagastrin for medullary carcinoma
In 39 people from affected families, seven showed a calcitonin rise only after pentagastrin injection, and some of these were found at operation to have focal medullary carcinoma and C-cell hyperplasia.
Separating carcinoma from hyperplasia
A pentagastrin-stimulated calcitonin peak of 275 ng/l distinguished medullary thyroid carcinoma from C-cell hyperplasia with 100% sensitivity and 89% specificity before surgery.
False positives in MEN 2A families
Among non-carriers in three MEN 2A families, 6.6% had false-positive basal calcitonin and 15.4% false-positive pentagastrin tests; the authors concluded RET gene analysis must be the first-line screen.
As a stimulus in acid studies
Pentagastrin-stimulated acid secretion was used to test intravenous pantoprazole, which suppressed acid output by more than 90% for up to 21 hours at 80 and 120 mg.
A research tool for provoking panic
In a double-blind challenge, pentagastrin, described as a synthetic analogue of cholecystokinin tetrapeptide acting on CCK-B receptors, produced panic-like reactions in 6 of 7 people with obsessive-compulsive disorder and 2 of 7 controls, a difference that did not reach significance.
Side Effects & Contraindications
Reported Side Effects
From the studies above.
Contraindications & Cautions
No current US label: the product is discontinued and DailyMed has no label (read October 3, 2026).
Legal Status
Pentagastrin is no longer marketed in the US.
Frequently Asked Questions
?What was pentagastrin used for?
As a diagnostic injection: to measure stomach acid secretion and to provoke calcitonin release when screening for medullary thyroid carcinoma.
?Is pentagastrin still available?
Not in the US, where Peptavlon is listed as discontinued. Genetic RET testing has replaced it as the first-line screen in affected families.
?How reliable was the pentagastrin test?
It could unmask small tumours, but in one family study 15.4% of people without the mutation had false-positive results.
?Why was pentagastrin used in psychiatry research?
It acts on cholecystokinin-B receptors and can trigger panic-like attacks, so researchers used it under controlled conditions to study panic and anxiety disorders. In one study it provoked panic-like reactions in 6 of 7 people with obsessive-compulsive disorder.
References
- [fda] US FDA, Drugs@FDA (openFDA): PEPTAVLON, NDA 017048 (July 26, 1974), marketing status discontinued; no label on DailyMed. Read October 3, 2026.
- [pubmed] Verdy M, et al. "Calcium infusion and pentagastrin injection in diagnosis of medullary thyroid carcinoma." Can Med Assoc J, 1978;119(1):29-35. PMID: 679097.
- [pubmed] Milone F, et al. "Predictive value of pentagastrin test for preoperative differential diagnosis between C-cell hyperplasia and medullary thyroid carcinoma in patients with moderately elevated basal calcitonin levels." Clin Endocrinol (Oxf), 2010;73(1):85-8. PMID: 20039894.
- [pubmed] Hernández G, et al. "False-positive results of basal and pentagastrin-stimulated calcitonin in non-gene carriers of multiple endocrine neoplasia type 2A." Thyroid, 1997;7(1):51-4. PMID: 9086571.
- [pubmed] Pisegna JR, et al. "Inhibition of pentagastrin-induced gastric acid secretion by intravenous pantoprazole: a dose-response study." Am J Gastroenterol, 1999;94(10):2874-80. PMID: 10520836.
- [pubmed] de Leeuw AS, et al. "Pentagastrin has panic-inducing properties in obsessive compulsive disorder." Psychopharmacology (Berl), 1996;126(4):339-44. PMID: 8878350.
Sources & Citations
Studies were read from their PubMed records; regulatory sources are listed below, read October 3, 2026.
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