GAWK (Chromogranin B 420-493)
A 74-amino-acid chromogranin-B peptide stored in neuroendocrine granules — a blood and tissue marker for endocrine tumors. A research peptide, not a drug
GAWK is a 74-amino-acid peptide cut from chromogranin B, one of the granins — the acidic proteins packed into the secretory granules of nerve and endocrine cells. Chromogranin A and secretogranin II give rise to a whole family of smaller active peptides covered elsewhere in this encyclopedia; GAWK is the chromogranin-B member, making it the third branch of that granin family. It was first isolated from human pituitary glands in 1985 — its odd name comes from the first four amino acids, glycine-alanine-tryptophan-lysine — and later matched to residues 420-493 of chromogranin B. GAWK is stored in the dense secretory granules of neuroendocrine cells across the pituitary, adrenal medulla, pancreas and gut, and is released together with hormones by regulated exocytosis. Its best-established use is diagnostic: like other granin peptides, GAWK spills into the blood from neuroendocrine tumors, and its level is raised in pancreatic islet-cell tumors, pheochromocytoma, medullary thyroid cancer and carcinoid, returning to normal after the tumor is removed — which makes it a useful tumor marker, especially for pancreatic endocrine tumors. Its own physiological signalling role has never been pinned down. GAWK is studied as a research peptide and a marker; it is not an approved medicine and has not been given to people as a treatment.
No established human dose Details ↓
Recommended Dosing
No established human dose
GAWK is an endogenous chromogranin-B-derived peptide that has never been given to people as a treatment. The human studies measure the body's own GAWK in tissue and plasma as a marker, and the rest of the work is in cells.
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What is it?
The granins are acidic proteins stored in the secretory granules of nerve and endocrine cells, where they are processed into many smaller peptides. Three granins dominate: chromogranin A, secretogranin II and chromogranin B. GAWK is the chromogranin-B peptide — a 74-amino-acid stretch corresponding to residues 420-493 of chromogranin B (also called secretogranin-1). It was discovered in 1985 during the purification of pituitary peptides, when a highly pure polypeptide 'bearing no resemblance to any known polypeptide' turned up; its full 74-residue sequence was solved, it was named GAWK for its first four amino acids, and it was localised to the anterior pituitary.
GAWK is a secretory-granule peptide of the neuroendocrine system. Immunostaining places it in the endocrine cells and nerves of the pituitary, adrenal medulla, pancreas and gut — in the gut mainly in serotonin-containing mucosal cells, stored in typical dense-core granules — and everywhere it occurs it co-exists with chromogranin B, supporting the precursor-product relationship. It is released by regulated exocytosis: in cultured chromaffin cells, high potassium or nicotine triggers its secretion, and in a medullary-thyroid-carcinoma cell line its release is driven by activators of protein kinase C and protein kinase A and by a calcium ionophore, implicating those signalling systems.
How GAWK is cut from chromogranin B differs by tissue. Comparing bovine adrenal medulla with anterior pituitary showed different processing products — multiple fragments in the adrenal medulla but a single small (~4 kDa) form in the pituitary — and antibodies to different parts of the peptide revealed species differences between human and bovine sequence. This tissue-specific and species-specific processing is a recurring theme in granin biology.
The practical value of GAWK is as a tumor marker. In a large survey of 194 tumors and 434 plasma samples, GAWK-like immunoreactivity was highest in pheochromocytoma (about ten-fold above other tumor types) and also elevated in carcinoid, medullary thyroid carcinoma, pancreatic and ACTH-producing lung tumors, while non-endocrine tumors had low levels; plasma GAWK was raised in endocrine-tumor patients — more so in pancreatic tumors — and normalised after successful removal. A separate study of pancreatic islet-cell tumors found plasma GAWK raised in half of patients and processed into several molecular forms, complementing the chromogranin-A peptide pancreastatin as a marker. GAWK's own physiological function, by contrast, remains undefined.
GAWK is an endogenous chromogranin-B-derived research peptide and marker. No published study has given GAWK to people as a treatment — the human work measures the body's own peptide in tissue and plasma, and the rest is cell work — it is approved nowhere, and material sold online as 'GAWK' is an unregulated research chemical. Nothing here is a dose or a therapy; this page records what the published science says about the peptide.
Mechanism of Action
GAWK is a 74-amino-acid peptide cut from chromogranin B (the chromogranin-B member of the granin family, alongside chromogranin-A and secretogranin-II peptides). It is stored in neuroendocrine secretory granules, released by regulated (PKC/PKA/calcium-dependent) exocytosis, processed tissue-specifically, and serves as a circulating and tissue marker of neuroendocrine tumours; its own signalling function is not established.
Chromogranin-B processing
GAWK is generated by proteolytic processing of chromogranin B (secretogranin-1), tissue-specifically, and co-exists with chromogranin B in neuroendocrine secretory granules (PMIDs 3970711, 3200116, 2715054).
Regulated secretion
GAWK is released by regulated exocytosis — triggered by depolarisation/nicotine in chromaffin cells and by protein kinase C, protein kinase A and calcium signalling in tumour cells (PMIDs 3200116, 19215381).
Neuroendocrine-tumour marking
Plasma and tissue GAWK rise in pheochromocytoma, pancreatic islet-cell and other neuroendocrine tumours and fall after removal, complementing the chromogranin-A peptide pancreastatin (PMIDs 2723061, 8288164).
Published Research
These are studies of GAWK read from their PubMed abstracts on November 6, 2026. They include its isolation and sequencing from human pituitary, human studies of GAWK as a neuroendocrine-tumour marker in tissue and plasma, a study of its distribution and co-localisation with chromogranin B, and studies of its tissue-specific processing and regulated secretion. GAWK has not been given to people as a treatment; the human work measures the body's own peptide.
Discovery and sequence of GAWK
During purification of human pituitary extracts, a highly pure 74-amino-acid polypeptide with no resemblance to known proteins was isolated and fully sequenced, and named GAWK for its N-terminal residues. An antibody to a synthetic fragment detected several immunoreactive forms and localised GAWK to the anterior pituitary — the first description of the peptide later identified as chromogranin B(420-493) (a biochemical isolation study).
GAWK is a neuroendocrine-tumour marker
Across 194 tumours and 434 plasma samples, GAWK (chromogranin-B 420-493) immunoreactivity was highest in pheochromocytoma — at least ten-fold above other tumours — and also high in carcinoid, medullary thyroid carcinoma, pancreatic and ACTH-producing lung tumours, with low levels in non-endocrine tumours. Plasma GAWK was elevated in endocrine-tumour patients (especially pancreatic) and returned to normal after tumour removal — supporting GAWK as a plasma tumour marker (a human observational study).
Plasma GAWK and pancreastatin in islet-cell tumours
In 12 patients with pancreatic islet-cell tumours, plasma pancreastatin (a chromogranin-A peptide) was raised in 33% and GAWK (a chromogranin-B peptide) in 50%, with no significant correlation between the two. Gel filtration of a gastrinoma patient's plasma showed pancreastatin as a single peak but GAWK as several molecular forms — indicating the two granin peptides are complementary, independently processed tumour markers (a human observational study).
GAWK distribution in human neuroendocrine tissues
In human gut, pancreas, adrenal and pituitary, GAWK immunoreactivity was localised — in the gut mainly to serotonin-containing mucosal cells (in dense-core granules) and some nerve fibres, and at the highest concentrations in the adrenal medulla and pituitary. GAWK-containing endocrine cells were also chromogranin-B-immunoreactive, giving morphological support for the precursor-product relationship between chromogranin B and GAWK (a human tissue study).
Tissue-specific processing of chromogranin B into GAWK
Chromogranin B(420-493) immunoreactivity was present in bovine adrenal-medulla chromaffin granules and the anterior pituitary and was released from cultured chromaffin cells by high potassium or nicotine. Different antibodies and chromatography showed multiple GAWK fragments in the adrenal medulla but a single ~4 kDa form in the pituitary, and a human-versus-bovine sequence difference — demonstrating tissue-specific (and species-specific) processing of chromogranin B into GAWK (a cell/biochemical study).
Regulated GAWK secretion from tumour cells
In a human medullary-thyroid-carcinoma cell line (TT cells), GAWK secretion was stimulated dose-dependently by the protein-kinase-C activator phorbol ester (TPA) and by the adenylate-cyclase activator forskolin, and increased by a calcium ionophore (with an additive effect when combined with TPA) — indicating GAWK is a regulated secretory peptide whose release involves protein kinase C, protein kinase A and calcium signalling (a cell study).
No Established Human Dose
GAWK is an endogenous chromogranin-B-derived peptide that has never been given to people as a treatment. The human studies measure the body's own GAWK in tissue and plasma as a marker, and the rest of the work is in cells. No regulator has approved any dose, and no published human dose exists, so no amount is printed here.
What this rests on: PMID 3970711, PMID 2723061, PMID 2715054.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, 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.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no label and no published test that says what forms or vial sizes GAWK (Chromogranin B 420-493) is sold in. A vial's own label is a seller's claim, not a source.
Mixing a vial: a worked example
Unknown: no human dose of GAWK (Chromogranin B 420-493) has been established (see No Established Human Dose below), so there is no amount to work out. The reconstitution calculator does the arithmetic for any vial, water and dose.
Storage before and after mixing
Unknown: no label or published stability study on file says how to store GAWK (Chromogranin B 420-493), before or after mixing. The mixing guide sets out the general rules, with their sources: keep a mixed vial in the fridge, and use it promptly, as the bacteriostatic water label says of any drug dissolved in it. The 28 days often quoted is the limit for an opened multiple-dose vial from a manufacturer, an outer limit set for sterility, not a time a mixed solution has been shown to keep. Nobody has published how long GAWK (Chromogranin B 420-493) stays intact once mixed.
How it is taken
Unknown: with no established human dose, there is no established way of taking GAWK (Chromogranin B 420-493). What the human studies gave and how is set out under No Established Human Dose.
What to expect, and when
How long it stays in the body: a half-life of not established for humans as a drug; an endogenous granin peptide. After about five half-lives almost none is left.
When effects appear: unknown; no source on this page gives a time to effect for GAWK (Chromogranin B 420-493). Results reported in the studies are under Published Research.
Source: half-life: PMID 3970711.
Side effects, and when to stop or get help
From the Side Effects section: No human adverse-event data exist: no published study has administered GAWK to people; The human studies measure endogenous GAWK as a neuroendocrine-tumour marker in tissue and plasma (PMIDs 2723061, 8288164); Its own physiological function and receptor are not established (PMID 2715054); Material sold online as 'GAWK' is an unregulated research chemical of unverified content. Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping GAWK (Chromogranin B 420-493). Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“GAWK is a research peptide and marker that has not been given to people as a drug, so there is no human safety profile; the points below reflect that research status”).
Interactions
Unknown: a PubMed search for human interaction studies of GAWK (Chromogranin B 420-493) (reviewed 2026-11-06) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of GAWK (Chromogranin B 420-493) products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: Research Chemical (Not a drug: Drugs@FDA and the openFDA label endpoint hold no record, and FDA GSRS and ChEMBL hold no substance record for GAWK (searched November 6, 2026)). Sport: Not on the 2026 List.
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
GAWK is a research peptide and marker that has not been given to people as a drug, so there is no human safety profile; the points below reflect that research status.
Contraindications & Cautions
GAWK has no approved use and no label. These points reflect its research status.
Legal Status
GAWK is an endogenous chromogranin-B-derived peptide studied as a research compound and tumour marker; it is not a drug and is not approved in any country.
Frequently Asked Questions
?What is GAWK?
A 74-amino-acid peptide cut from chromogranin B (residues 420-493), first isolated from human pituitary and named for its first four amino acids (Gly-Ala-Trp-Lys). It is the chromogranin-B member of the granin peptide family.
?What does it do?
Its own physiological role is not established, but it is a secretory-granule peptide of neuroendocrine cells and a useful blood and tissue marker for endocrine tumors — raised in pancreatic islet-cell tumors, pheochromocytoma and others, and falling after removal (PMIDs 2723061, 8288164).
?How is it related to pancreastatin and secretoneurin?
All are granin peptides: GAWK comes from chromogranin B, pancreastatin from chromogranin A, and secretoneurin from secretogranin II. GAWK and pancreastatin are complementary neuroendocrine-tumour markers. Grey Peptides has separate entries for those peptides.
?Is it approved or available to buy?
No. GAWK is not a medicine, has no FDA application or label, and is approved nowhere; it is studied as a research peptide and a tumour marker. Material sold online as GAWK is an unregulated research chemical. Grey Peptides lists no sellers and recommends no source; this page records the published science.
References
- [mechanism] Benjannet S, et al. "GAWK, a novel human pituitary polypeptide: isolation, immunocytochemical localization and complete amino acid sequence." Biochem Biophys Res Commun, 1985;126(1):602-9. PMID: 3970711.
- [clinical-trial] Sekiya K, et al. "Production of GAWK (chromogranin-B 420-493)-like immunoreactivity by endocrine tumors and its possible diagnostic value." J Clin Invest, 1989;83(6):1834-42. PMID: 2723061.
- [clinical-trial] Yasuda D, et al. "Comparison of plasma pancreastatin and GAWK concentrations, presumed processing products of chromogranin A and B, in plasma of patients with pancreatic islet cell tumors." Horm Metab Res, 1993;25(11):593-5. PMID: 8288164.
- [mechanism] Bishop AE, et al. "The distribution of GAWK-like immunoreactivity in neuroendocrine cells of the human gut, pancreas, adrenal and pituitary glands and its co-localisation with chromogranin B." Histochemistry, 1989;90(6):475-83. PMID: 2715054.
- [mechanism] Iguchi H, et al. "Different processing of chromogranin B into GAWK-immunoreactive fragments in the bovine adrenal medulla and pituitary gland." Life Sci, 1988;43(23):1945-52. PMID: 3200116.
- [mechanism] Iguchi H, et al. "Secretion of GAWK, a Presumed Product of Chromogranin B Processing, by a Human Medullary Thyroid Carcinoma Cell Line: Effect of Phorbol Ester, Forskolin and Calcium-lonophore." J Neuroendocrinol, 1990;2(4):505-8. PMID: 19215381.
- [other] UniProt P05060 (secretogranin-1 / chromogranin B, CHGB gene), read November 6, 2026: GAWK is a 74-amino-acid peptide corresponding to chromogranin B residues 420-493, generated by proteolytic processing of chromogranin B (also called secretogranin-1). https://www.uniprot.org/uniprotkb/P05060/entry
- [other] GAWK was isolated from human pituitary during purification work and its complete 74-residue sequence determined (it is named for its N-terminal Gly-Ala-Trp-Lys); it was later shown to be chromogranin B(420-493). Its secretory-granule storage, tissue-specific processing and use as a neuroendocrine-tumour marker are from the studies carded on this page (read November 6, 2026).
- [other] US FDA, Drugs@FDA and the drug label endpoint (openFDA), searched November 6, 2026: no application and no label record for GAWK / chromogranin B(420-493). It is an endogenous peptide, not a registered drug; FDA GSRS and ChEMBL hold no substance record for it.
Sources & Citations
The six studies carded above were read from their PubMed records on November 6, 2026. Identity comes from UniProt (P05060, secretogranin-1/chromogranin B): GAWK is chromogranin B(420-493), a 74-residue peptide. Its isolation and sequencing from human pituitary, its secretory-granule storage and regulated, tissue-specific processing, its distribution across neuroendocrine tissues and co-localisation with chromogranin B, and its use as a circulating and tissue marker of neuroendocrine tumours are from the studies carded on this page; the absence of US approval and of a drug substance record from Drugs@FDA, openFDA, FDA GSRS and ChEMBL was checked the same day. Grey Peptides sells nothing and links to no vendor.
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.