AssayIndex
Incretin analogues and co-agonists

Glucagon

GCG (1-29) · native human glucagon · C153H225N43O49S · monoisotopic 3480.6194 Da. The index holds 10 assay reports on this compound across 3 batches from 3 suppliers.

10 reports3 batchesmedian 98.78 %index spec 98.0 %
Section 1

Analytical fingerprint

Hand-authored chemistry. These properties describe the substance and do not change when a record is added.

Native glucagon fibrillates faster than anything else in the index. A reconstituted vial held at 25 °C in dilute acid will show visible gel within 24–48 h, and the index has rejected several reports where the submitter's own reconstitution step, not the lot, produced the aggregate peak at +2.6 min. Sample-preparation detail is therefore mandatory on glucagon submissions and the record page prints it verbatim. Analytically the compound is easy: 13.6 min, sharp, single dominant impurity (Met27 sulfoxide). Base peak [M+3H]3+ at m/z 1161.22.

Molecular formula
C153H225N43O49S
Monoisotopic mass
3480.6194Da
Average mass
3482.75Da
Residues
29
Nominal retention (RG-2, 30 min)
13.61min
Retention window
0.35min
Counter-ion as usually shipped
acetate
Typical label claims
1 mg · 2 mg · 5 mg
Analytical difficulty (index scale)
1.10 — straightforward
Purity is a defined quantity
YES
Section 2

Representative chromatogram

Drawn from this page's own medians. Not a scan, not an illustration, and not any single report.

01960392058807839 Glucagon13.61 min · 98.78 % 13.2516.22 same trace · ×100 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
Figure 1. A representative Glucagon trace on the index reference method RG-2, constructed from this page's own numbers: the main peak carries the index median purity of 98.78 % area at the nominal retention time of 13.61 min, and each impurity peak carries the median area the index has observed for that named species at its characteristic retention offset. It is not a scan of any single report — every individual record's own chromatogram is on its own page. The lower panel is the same trace at a stated vertical expansion, baseline-corrected, so the impurities are visible; the main peak runs off-scale there by design. Baseline noise is seeded from the compound slug.
Section 3

What the index has observed

Arithmetic over the 10 records the index holds. Aggregates on this page are computed over the records the index holds, which are not a random sample of the material on the market. Lots that get tested are lots someone chose to test. Read every figure here as a description of this dataset rather than as an estimate of a population.

Median purity 98.78% n=10
Interquartile range 1.22pp n=10
Minimum 97.76% n=10
Maximum 99.85% n=10
Pass rate vs spec 70.0% n=10
Median recovery vs claim 96.4% n=7
Median water 7.25% n=10
Median |mass error| 1.7ppm n=9

Fewer than twelve purity records (n=10) — a histogram of this would be a picture of the sample size rather than of the compound. The individual values are in the table below.

Section 4

By supplier

Suppliers with fewer than two purity records on this compound are omitted from the figure rather than drawn as a line. The full table, including the thin cells, is on the by-supplier page.

97.697.998.298.598.899.199.4SSASSA: Q1 98.28, median 98.91, Q3 99.17, n=7n=7ERPERP: Q1 97.96, median 98.03, Q3 98.09, n=2n=2 Purity (% area)
Figure 3. Glucagon purity by supplier, ordered by coverage. The vertical line is the index acceptance specification. Boxes that overlap are suppliers this dataset cannot separate, and most of them overlap.

Full per-supplier table with n= caveats →

Section 5

Characteristic impurities and degradants

The left three columns are authored chemistry — what this molecule characteristically carries and where it elutes. The right three are what the index has actually reported.

Named speciesΔRT (min, RG-2)Δ mass (Da)Seen inMedian % areaMax % area
Met27 sulfoxide (+16 Da)-0.79+15.995100%0.230.71
deamidated Asn28 (+1 Da)-0.36+0.984100%0.391.11
des-His1 (−137 Da)-0.94-137.059100%0.080.26
glucagon fibril-derived aggregate+2.61mass-identical90%0.271.08

Degradation pathways

  • fibrillation within hours at acidic pH and room temperature — the classic instability
  • Met27 oxidation
  • Asn28 deamidation

Full impurity profile, with what each named species implies about the synthesis →

Section 6

Clinical context

Included because it is routinely misapplied. Trial data describes a licensed medicinal product manufactured under a marketing authorisation, and it does not transfer to research-grade material of unknown provenance.

Glucagon has been in clinical use since 1960 for severe hypoglycaemia; it appears in the index mostly as a reference standard rather than as a research purchase.

Section 7

Quarterly coverage

QuarterReportsMedian purityRange
2024-Q10n<3—
2024-Q20n<3—
2024-Q3798.9197.76–99.32
2024-Q40n<3—
2025-Q10n<3—
2025-Q20n<3—
2025-Q30n<3—
2025-Q40n<3—
2026-Q12n<397.90–98.15
2026-Q21n<3—
2026-Q30n<3—

Quarter-by-quarter detail →

Section 8

Most recent records

The 25 most recent Glucagon records of 10.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042166HomopeptideHOMO-2602-V9076Nordanalyt2026-Q299.856.11101.5Supplier-supplied0PASS
AX-2026-042529ERPERP-2601-X6637Janoshik2026-Q197.901.8695.6Supplier-supplied0FAIL
AX-2026-042530ERPERP-2601-X6637VendorInvestigate2026-Q198.151.28—Buyer-sourced0PASS
AX-2024-005227SSASSA-2408-F7210Janoshik2024-Q398.647.5396.4Supplier-supplied1MARGINAL
AX-2024-005230SSASSA-2408-F7210Janoshik2024-Q397.767.1291.8Buyer-sourced0FAIL
AX-2024-005226SSASSA-2408-F7210Nordanalyt2024-Q399.327.88—Supplier-supplied1MARGINAL
AX-2024-005225SSASSA-2408-F7210PeptideMeter2024-Q398.917.90103.0Supplier-supplied1MARGINAL
AX-2024-005229SSASSA-2408-F7210Janoshik2024-Q399.147.2392.7Supplier-supplied2MARGINAL
AX-2024-005231SSASSA-2408-F7210VendorInvestigate2024-Q397.917.51102.9Buyer-sourced0FAIL
AX-2024-005228SSASSA-2408-F7210PeptideMeter2024-Q399.217.27—Supplier-supplied1MARGINAL