Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.
Five residues that reproduce gastrin's entire acid-secreting message — used for half a century to test the stomach, and, unexpectedly, to provoke panic in the laboratory.
Also known as: Peptavlon · ICI 50123 · Boc-β-Ala-Trp-Met-Asp-Phe-NH2
Part of the Foundational & therapeutic peptides cluster
Overview
Pentagastrin (Peptavlon) is a synthetic five-residue peptide — Boc-β-Ala-Trp-Met-Asp-Phe-NH2 — built on the C-terminal tetrapeptide shared by gastrin and cholecystokinin. Acting through the CCK-B/gastrin receptor it is a powerful stimulator of gastric acid secretion, approved by the US FDA in 1974 as a diagnostic test of acid secretory function. Because CCK-B receptors are also present in the brain, it has been used as an experimental panic-provocation agent.
Source & context
Biological / chemical source: Synthetic pentapeptide based on the C-terminal tetrapeptide of gastrin and CCK
Primary research or clinical context: Approved (US FDA, 1974) as a diagnostic aid for evaluating gastric acid secretory function; also used experimentally as a panic-provocation challenge
What pentagastrin is
Pentagastrin is a synthetic diagnostic peptide built from the smallest fragment of gastrin that still works. Gastrin and cholecystokinin share a C-terminal tetrapeptide, Trp-Met-Asp-Phe-NH2, that carries their receptor-activating message; pentagastrin adds a protected β-alanine to the front of it, giving five residues and a stable, injectable molecule. Marketed as Peptavlon (ICI 50123), it is a powerful stimulator of gastric acid secretion and was approved by the US FDA in 1974 as a diagnostic aid for evaluating gastric acid secretory function (IUPHAR record; Hulstaert et al., Scandinavian Journal of Gastroenterology 1980).
Sequence and chemistry
The IUPHAR record writes the sequence as XWMDF, where X is the N-terminal Boc-β-alanine — a β-amino acid carrying a tert-butoxycarbonyl protecting group — and the C-terminal phenylalanine is amidated. The chip display above uses X for that non-standard residue. IUPHAR also notes some disagreement between databases about the exact structure and stereochemistry, with an alternative representation held in ChEMBL; the molecular formula C37H49N7O9S and mass of about 768 Da in the structure block are from the PubChem record.
Mechanism
Like gastrin, pentagastrin is thought to act through cholecystokinin-B receptors on gastric cells to induce acid secretion, although IUPHAR notes it could not locate human receptor affinity data to substantiate that assignment. Whether its effect is direct or mediated by histamine has been studied in patients: pentagastrin infusion induced parallel secretion of acid and histamine in duodenal ulcer patients, and cimetidine blockade cut acid output rapidly without changing gastric histamine output (Man et al., Gut 1984). In anaesthetised dogs, pentagastrin dose-dependently increased splanchnic blood flow in a reversed U-shaped pattern (Hulstaert et al. 1980).
Pharmacokinetics and development
Pentagastrin is rapidly removed from the circulation of the dog and excreted by the liver into bile, largely in an inactivated form, with preliminary evidence of the same fate in humans (Stagg et al., Gut 1971). In the rat, gastric sensitivity to pentagastrin appears on fetal day 20 and then develops in a biphasic pattern, being low again in five-day-old pups (Garzon et al., American Journal of Physiology 1982).
The panic-provocation test
CCK-B receptors are abundant in the brain, and CCK-4 — the same tetrapeptide pentagastrin is built on — provokes panic-like anxiety. Pentagastrin has been used as a controlled experimental challenge: in obsessive-compulsive disorder, six of seven patients (86%) experienced a panic-like reaction after an intravenous dose of 0.6 μg/kg versus two of seven controls (29%) under double-blind conditions (de Leeuw et al., Psychopharmacology 1996). In healthy volunteers, escalating bolus doses raised galvanic skin response and heart rate within a minute, and personality measures were examined as predictors of the response (Radu et al., Psychopharmacology 2003).
Research use in cancer biology
Because gastrin can act as a growth factor for some gastrointestinal tumours, pentagastrin is used as an experimental tool in cell culture. In HT-29 colorectal cancer cells, pentagastrin-regulated growth was studied through the CCK-B receptor and the ERK–MAPK signalling pathway, with the receptor antagonist proglumide as a control (Mao et al., World Journal of Gastroenterology 2014).
Relation to other peptides on this site
Pentagastrin is the pharmacological shorthand for two hormones profiled here, gastrin and cholecystokinin, whose shared C-terminal tetrapeptide it isolates. It is a diagnostic and research reagent, not a therapy, and the ClinicalTrials.gov entries that mention it are mostly acid-secretion studies in which it served as the stimulus.
Sequence of the selected reference form
Sequence backbone for the reference form: Pentagastrin, Boc-beta-Ala1 and Phe5-amide. Termini, stereochemistry and modifications are described below.
XWMDF
X positions 1: N-Boc beta-alanine; not alpha-alanine. X marks a noncanonical residue; see the expanded sequence and reference chemistry below.
Analyze sequences in the playground →Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
GSRS structure, full standard InChI and PUBCHEM code match CID9853654. Its structure explicitly contains tert-butoxycarbonyl on beta-alanine and four specified L-amino-acid centers; GSRS reports average molecular weight767.894. NLM MeSH nomenclature independently identifies the1,1-dimethylethoxycarbonyl-beta-alanyl chain. Its IUPAC structure contains2-methylpropoxycarbonyl (isobutoxycarbonyl), a different constitutional group from2-methylpropan-2-yloxycarbonyl (tert-butoxycarbonyl/Boc). The same formula and mass do not make these identical. Its standard InChIKeyALXRNCVIQSDJAO-KRCBVYEFSA-N differs in the connectivity block.
- Molecular form
- Pentagastrin, Boc-beta-Ala1 and Phe5-amide
- Species
- Synthetic gastrin analogue; not a species-derived natural peptide
- Termini (N / C)
- N-tert-butoxycarbonyl beta-alanine (Boc-beta-Ala) / Phe carboxamide
Average reference mass · Molecular identity assessment: 2026-10-05
Reference policy updated: 2026-10-05
- PubChem PUG molecular properties, CID 9853654 · 2026-10-05
- PubChem structure-derived biologic notation, CID 9853654 · 2026-10-05
- NIH NCATS/FDA GSRS, UNII EF0NX91490 · 2026-10-05
- NLM MeSH Pentagastrin2026 descriptor · 2026-10-05
Boc-bAla-Trp-Met-Asp-Phe-NH2
- Molecular formula
- C37H49N7O9S
- Average reference mass
- ≈ 767.89
- Receptors
- Cholecystokinin-B (CCK-B / gastrin) receptor, inferred from its gastrin-like action; IUPHAR notes no human affinity data were located
- Backbone
- Pentagastrin, Boc-beta-Ala1 and Phe5-amide
- C-terminus
- Phe carboxamide
- Status
- Approved: US FDA, 1974 (diagnostic aid for gastric acid secretory function)
- PubChem CID: 9853654
- CAS RN: 5534-95-2
- UNII: EF0NX91490
Chemistry values: curated profile, PubChem.
Clinical development snapshot
ClinicalTrials.gov lists 7 registered studies with “Pentagastrin” as an intervention (snapshot 2026-09-07). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT00702533 | A New Method for Determining Gastric Acid Output Using a Wireless Capsule | — | completed | 2026-08-31 |
| NCT01601418 | Effect of Single Doses of YF476 on Stomach Acidity | Phase 1 | completed | 2012-05-18 |
| NCT01601405 | Effect of Repeated Doses of YF476 on Stomach Acidity | Phase 1 | completed | 2012-05-18 |
| NCT00629564 | An Open, Randomized, Two Way Crossover Study Comparing the Effect of 20mg Esomeprazole Administered Orally and | Phase 4 | completed | 2011-01-25 |
| NCT00635414 | Open, Randomized, Two Way Crossover 40mg, Orally and Intravenously | Phase 4 | completed | 2011-01-25 |
| NCT00626262 | Open, Randomized, Two Way Crossover Study Comparing the Effect of Esomeprazole Adminstered Orally and iv | Phase 4 | completed | 2011-01-24 |
Pentagastrin — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Pentagastrin, Boc-beta-Ala1 and Phe5-amideAverage reference mass: 767.894 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- IdentifiersCross-linked to IUPHAR ligand 870 and PubChem CID 444007.
- TrialsClinicalTrials.gov snapshot added: 7 registered studies, highest phase 4.
- EditorialProfile content reviewed and updated by the editorial team.
FAQ about Pentagastrin
What is Pentagastrin?+
Pentagastrin (Peptavlon) is a synthetic five-residue peptide — Boc-β-Ala-Trp-Met-Asp-Phe-NH2 — built on the C-terminal tetrapeptide shared by gastrin and cholecystokinin. Acting through the CCK-B/gastrin receptor it is a powerful stimulator of gastric acid secretion, approved by the US FDA in 1974 as a diagnostic test of acid secretory function. Because CCK-B receptors are also present in the brain, it has been used as an experimental panic-provocation agent.
What Canadian product status is recorded for Pentagastrin?+
Canadian product status for Pentagastrin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the length of the selected reference form for Pentagastrin?+
The selected reference form (Pentagastrin, Boc-beta-Ala1 and Phe5-amide) has 5 residues or residue-derived units in its backbone. Other forms in this family may have a different length.
What is pentagastrin?+
A synthetic five-residue gastrin analogue (Boc-β-Ala-Trp-Met-Asp-Phe-NH2) that stimulates gastric acid secretion. FDA-approved in 1974 as a diagnostic test of stomach acid function.
How does pentagastrin work?+
It reproduces the C-terminal tetrapeptide of gastrin and CCK and is thought to act on CCK-B/gastrin receptors to trigger acid secretion, partly via histamine release.
Why is pentagastrin used in anxiety research?+
CCK-B receptors in the brain mediate panic-like responses; in one study 86% of OCD patients versus 29% of controls had a panic-like reaction after an intravenous dose.
What is the sequence of pentagastrin?+
XWMDF in one-letter code, where X is an N-terminal Boc-protected β-alanine and the C-terminal phenylalanine is amidated.
Is pentagastrin a treatment?+
No. It is a diagnostic aid and laboratory tool, not a therapeutic medicine.
Related peptides
References & further reading
- 1.Hulstaert PF et al. (1980). Hemodynamic actions of pentagastrin. Scandinavian Journal of Gastroenterology
- 2.Stagg BH et al. (1971). The fate of pentagastrin. Gut
- 3.Man WK et al. (1984). Is pentagastrin-stimulated secretion mediated by histamine? Gut
- 4.de Leeuw AS et al. (1996). Pentagastrin has panic-inducing properties in obsessive compulsive disorder. Psychopharmacology
- 5.Radu D et al. (2003). Pentagastrin test for anxiety—psychophysiology and personality. Psychopharmacology
- 6.Mao JD et al. (2014). Role of ERK-MAPK signaling pathway in pentagastrin-regulated growth of large intestinal carcinoma. World Journal of Gastroenterology
- 7.PubChem — Pentagastrin (CID 444007)