AssayIndex

WXT-2512-P4522

L-Glutathione (reduced) · 600 mg declared · WuXi TIDES (WuXi AppTec Testing Division) · manufactured 03 Dec 2025

CHARACTERISED
Lot code
WXT-2512-P4522
Supplier
WXT — WuXi TIDES (WuXi AppTec Testing Division)
Compound
L-Glutathione (reduced)
Compound class
Short bioregulator peptides
Declared label claim
600mg
Manufacture date
03 Dec 2025
Index quarter
2026-Q2
Independent assays
8
Laboratories involved
Medutest, Nordanalyt, VendorInvestigate, Janoshik, Kestrel
Provenance mix
Buyer-sourced ×6 · Supplier-supplied ×1 · Laboratory-retained ×1
Section 1

Reproducibility across independent tests

Every report below is an observation of the same physical material. What they disagree about is measurement; what they agree about is the lot. The size of the disagreement is compared against what the contributing laboratories' own repeatability figures predict.

Independent assays 8
Median purity 98.29% n=8
Spread (max − min) 0.92pp n=8
Standard deviation 0.301pp n=8
97.497.898.398.799.299.7100.1This lot (WXT-2512-P4522)This lot (WXT-2512-P4522): Q1 98.17, median 98.29, Q3 98.53, n=8n=8All L-Glutathione (reduced)All L-Glutathione (reduced): Q1 98.80, median 99.24, Q3 99.63, n=143n=143 Purity (% area)
Figure 1. This lot's independent purity results against the whole L-Glutathione (reduced) record set in the index. The vertical line is the index acceptance specification for the short bioregulator peptides class, 98.5 % area. A narrow box on the top row against a wide box on the bottom row is the ideal reading: it means the disagreement between lots is much larger than the disagreement within this one.
Section 2

Member reports 8

Every report the index holds on this lot. Each is a page carrying its own chromatogram, mass spectrum, mass balance, provenance and caveats.

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043503WXT-2512-P4522Medutest2026-Q298.538.84Buyer-sourced0PASS
AX-2026-043504WXT-2512-P4522Nordanalyt2026-Q298.548.78101.4Buyer-sourced0PASS
AX-2026-043505WXT-2512-P4522VendorInvestigate2026-Q298.229.03Buyer-sourced0FAIL
AX-2026-043506WXT-2512-P4522Medutest2026-Q298.368.60Supplier-supplied1FAIL
AX-2026-043507WXT-2512-P4522Medutest2026-Q298.078.52Buyer-sourced0FAIL
AX-2026-043508WXT-2512-P4522VendorInvestigate2026-Q297.728.91103.9Laboratory-retained0FAIL
AX-2026-043509WXT-2512-P4522Janoshik2026-Q298.209.0199.0Buyer-sourced0FAIL
AX-2026-043510WXT-2512-P4522Kestrel2026-Q298.648.69102.2Buyer-sourced0PASS
Section 3

By laboratory

Where more than one laboratory assayed this lot, the difference between them is a paired observation of their relative bias — the same material, the same time window, different instruments. Those pairs are what the index's bias estimates are built from.

LaboratoryReportsPurity results (% area)MedianGradientPublished bias (pp)Bias-adjusted
Medutest398.53, 98.36, 98.0798.3625min+0.0898.28
Nordanalyt198.5498.5435min+0.0298.52
VendorInvestigate298.22, 97.7297.9732min-0.1198.08
Janoshik198.2098.2030min+0.0098.20
Kestrel198.6498.6415min+0.2498.40

This lot contributes 10 paired comparisons to the inter-lab analysis.

Section 4

The supplier's certificate for this lot

One number the supplier wrote, beside the median of the numbers other people measured on the same physical material. That comparison is only available because the index groups by lot.

FigureSupplier COAThis reportIndex note
Purity (% area)98.2598.53divergence -0.04 pp vs batch median
Total impurities (% area)not stated1.47
Largest single impurity (% area)not stated0.76
Water (%)not stated8.84
Counter-ion (%)3.5N/A
Peptide content (%w/w)92.4not determined
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Impurity fingerprint

The named impurities reported across this lot's assays, with how consistently each was seen. A fingerprint is what allows two lot numbers held by different companies to be identified as one bulk.

Named impurityReported inMedian % areaRange
γ-Glu-Cys (−57 Da)8 / 80.670.34–1.00
S-sulfonate adduct (+80 Da)8 / 80.280.10–0.53
glutathione disulfide (GSSG, +305 Da)8 / 80.510.19–1.29
cysteinyl-glycine (−129 Da)8 / 80.150.11–0.25
Section 7

What this rollup does not establish