Glucagon Unit Converter
Glucagon Unit Converter
Convert plasma glucagon between pg/mL, ng/L and pmol/L. A rarely measured hormone with essentially one indication — suspected glucagonoma — and a mild elevation that is usually something else entirely.
Glucagon converter
Mass ⇄ molarFasting plasma glucagon 55 pg/mL
The three units
pmol/L = pg/mL × 0.287125
derived from a molecular weight of 3,482.8 Da for glucagon(1–29)
- pg/mL = ng/L
- a picogram per millilitre and a nanogram per litre are the same concentration, so no conversion is needed between the two mass conventions
- × 0.287125
- the molar factor, from the mass of the 29-residue mature peptide, 3,482.8 daltons. The reciprocal is 3.483, so dividing pg/mL by 3.5 is a serviceable mental approximation
- which glucagon the assay sees
- glucagon is cleaved from proglucagon, which also yields glicentin, oxyntomodulin and the glucagon-like peptides. Older radioimmunoassays cross-reacted with these, inflating results; modern sandwich assays are specified to detect only full-length glucagon(1–29). Mayo states its method does not cross-react with fragments or related peptides
- why methods disagree
- because of that history, absolute glucagon values differ substantially between assays, and a result from one laboratory should not be compared with a result from another. Serial measurements should use the same method throughout
- read with the glucose
- glucagon opposes insulin, so the number only means something alongside a simultaneous glucose. A raised glucagon with hypoglycaemia is a physiological counter-regulatory response; a raised glucagon with hyperglycaemia is the pattern that suggests a glucagon-secreting tumour
Worked example
Fasting plasma glucagon 55 pg/mL
55 pg/mL = 55 ng/L — the same number in the other mass convention
55 × 0.287125 = 15.79 pmol/L
The quick check: 55 ÷ 3.5 = 15.7, close enough for a bedside estimate
Against the quoted interval of 0–159 pg/mL (0.00–45.65 pmol/L) for age 1 year and over, 55 pg/mL sits within it
For scale: glucagonoma typically presents with values many times this upper limit, so a result sitting just above 159 pg/mL points towards the mundane causes in the table below rather than towards a tumour
How high is high — interpreting a raised fasting glucagon
| Level | Usual explanations | What to do with it |
|---|---|---|
| Within the interval | Normal | Glucagonoma is unlikely; look elsewhere for the cause of the presentation |
| Mildly raised, up to roughly two or three times the upper limit | Diabetes, prolonged fasting, physical or surgical stress, renal failure, cirrhosis, obesity, acromegaly, Cushing’s syndrome, pancreatitis, familial hyperglucagonaemia | Non-specific. Repeat fasting on the same assay, correct the obvious contributors and look at the clinical picture before imaging |
| Markedly raised, many times the upper limit | Glucagonoma, particularly with hyperglycaemia, weight loss, necrolytic migratory erythema, anaemia and venous thrombosis | Investigate as a neuroendocrine tumour: cross-sectional imaging and specialist referral |
Getting a glucagon specimen right
| Requirement | Detail |
|---|---|
| Fasting | Mayo specifies an 8-hour fast; glucagon responds to protein-containing meals |
| Tube | EDTA (lavender top), pre-chilled |
| Handling | Chill the filled tube in wet ice, centrifuge in a refrigerated centrifuge, freeze the plasma immediately in a plastic vial |
| Why | Glucagon is a small peptide degraded by plasma proteases; a warm, delayed specimen reads low |
| Assay | Modern sandwich assays measure only full-length glucagon(1–29) and do not cross-react with glicentin, oxyntomodulin or GLP-1; older radioimmunoassays did |
| Comparability | Values differ between methods — keep serial measurements on one assay |
One indication, one pattern, and a great many mild elevations
Glucagon is the pancreatic alpha-cell hormone that opposes insulin, raising blood glucose by driving hepatic glycogenolysis and gluconeogenesis. Despite that central physiological role it is very rarely measured, because in almost every clinical situation the glucose itself is the more useful number. The one established indication is suspected glucagonoma: a rare pancreatic neuroendocrine tumour presenting with hyperglycaemia, weight loss, anaemia, venous thrombosis, depression and the characteristic rash called necrolytic migratory erythema. In that setting the glucagon is typically not marginally raised but many times the upper limit of normal.
That last point governs how a result should be read. Mild elevations of fasting glucagon are common and largely non-specific. Diabetes raises it; so do prolonged fasting, acute physical or surgical stress, obesity, cirrhosis, pancreatitis, acromegaly and Cushing’s syndrome. Chronic kidney disease raises it because glucagon is cleared renally, which makes renal function an essential piece of context for any raised value. There is also a recognised familial hyperglucagonaemia in which the level is high and nothing is wrong. A glucagon sitting just above the reference interval therefore says very little, and the appropriate next step is usually to repeat it fasting on the same assay and to look at the clinical picture rather than to proceed straight to imaging.
The measurement itself is technically demanding, which is the second reason results should be treated with caution. Glucagon is cleaved from proglucagon, a precursor that also gives rise to glicentin, oxyntomodulin and the glucagon-like peptides, and the radioimmunoassays used historically cross-reacted with those relatives and produced inflated and poorly comparable figures. Contemporary sandwich assays are specified to detect only the full-length 29-residue peptide, but absolute values still differ substantially between methods, so a result from one laboratory cannot be set against a result from another and serial monitoring must stay on a single assay. The peptide is also fragile: the specimen needs a pre-chilled EDTA tube, wet ice, a refrigerated centrifuge and immediately frozen plasma, or it reads low.
Finally, glucagon is interpreted with a simultaneous glucose. The hormone exists to defend against hypoglycaemia, so a high glucagon during a low glucose is the counter-regulatory system doing its job. It is the combination of a high glucagon with a high glucose that is abnormal and that points towards a glucagon-secreting tumour. The mirror-image finding — glucagon failing to rise during hypoglycaemia — is a feature of long-standing type 1 diabetes and contributes to impaired awareness of hypoglycaemia, but it is demonstrated by a dynamic study rather than by the fasting number this page converts. The units, at least, are simple: picograms per millilitre and nanograms per litre are the same, and picomoles per litre is that number multiplied by 0.287125.
Frequently asked questions
How do I convert glucagon from pg/mL to pmol/L?
Multiply by 0.287125, from a molecular weight of 3,482.8 daltons for the 29-residue mature peptide. A glucagon of 55 pg/mL is 15.79 pmol/L. Picograms per millilitre and nanograms per litre are the same number, and dividing pg/mL by 3.5 is a reasonable mental approximation.
What glucagon level suggests a glucagonoma?
Not a mildly raised one. Glucagonoma characteristically produces values many times the upper limit of normal, usually alongside hyperglycaemia, weight loss, anaemia and necrolytic migratory erythema. A result just above the reference interval is far more likely to reflect diabetes, fasting, stress, renal failure, cirrhosis or obesity.
What causes a mildly raised glucagon?
A long list of non-specific things: diabetes, prolonged fasting, acute physical or surgical stress, obesity, chronic kidney disease — glucagon is renally cleared — cirrhosis, pancreatitis, acromegaly, Cushing’s syndrome, and a recognised familial hyperglucagonaemia in which the level is high and no disease is present.
Why do glucagon results differ between laboratories?
Because the assay is technically difficult. Glucagon shares its precursor with glicentin, oxyntomodulin and the glucagon-like peptides, and older radioimmunoassays cross-reacted with them. Modern sandwich assays measure only full-length glucagon(1–29), but absolute values still vary between methods, so serial measurements should stay on one assay.
How should a glucagon sample be collected?
Fasting — Mayo Clinic Laboratories specifies eight hours — into a pre-chilled EDTA tube, chilled in wet ice, centrifuged in a refrigerated centrifuge and the plasma frozen immediately. Glucagon is a small peptide degraded by plasma proteases, so a warm or delayed specimen gives a spuriously low result.
Related calculators
References
- Mayo Clinic Laboratories. Test GLP: Glucagon, Plasma — reference value <159 pg/mL for age 1 year and over; 8 hour fast, chilled EDTA collection; assay specificity for glucagon(1–29). Accessed 2026.
- Wewer Albrechtsen NJ, Hartmann B, Veedfald S, et al. Hyperglucagonaemia analysed by glucagon sandwich ELISA: nonspecific interference or truly elevated levels? Diabetologia. 2014;57(9):1919–1926.
- Eldor R, Glaser B, Fraenkel M, et al. Glucagonoma and the glucagonoma syndrome — cumulative experience with an elusive endocrine tumour. Clin Endocrinol (Oxf). 2011;74(5):593–598.
- Cryer PE. Mechanisms of hypoglycemia-associated autonomic failure in diabetes. N Engl J Med. 2013;369(4):362–372 — on the loss of the glucagon response in type 1 diabetes.
Medical Disclaimer: The tools and content provided here are for educational and reference purposes only. They are not intended to substitute for professional medical advice, diagnosis, or treatment. Clinical decisions should always be based on the comprehensive assessment of a qualified healthcare professional.