AssayIndex

CPC-2602-D2535

L-Glutathione (reduced) · 1500 mg declared · Chinese Peptide Company Co., Ltd. · manufactured 23 Feb 2026

CHARACTERISED
Lot code
CPC-2602-D2535
Supplier
CPC — Chinese Peptide Company Co., Ltd.
Compound
L-Glutathione (reduced)
Compound class
Short bioregulator peptides
Declared label claim
1500mg
Manufacture date
23 Feb 2026
Index quarter
2026-Q1
Independent assays
9
Laboratories involved
Janoshik, Nordanalyt, Medutest, Kestrel
Provenance mix
Supplier-supplied ×9
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 9
Median purity 98.28% n=9
Spread (max − min) 0.91pp n=9
Standard deviation 0.312pp n=9
96.196.897.598.298.899.5100.2This lot (CPC-2602-D2535)This lot (CPC-2602-D2535): Q1 98.15, median 98.28, Q3 98.58, n=9n=9All L-Glutathione (reduced)All L-Glutathione (reduced): Q1 98.58, median 99.00, Q3 99.57, n=122outlier 96.39n=122 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 9

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-2026-043303CPC-2602-D2535Janoshik2026-Q198.687.52—Supplier-supplied0PASS
AX-2026-043304CPC-2602-D2535Nordanalyt2026-Q198.127.51—Supplier-supplied0FAIL
AX-2026-043305CPC-2602-D2535Medutest2026-Q198.288.5990.0Supplier-supplied0FAIL
AX-2026-043306CPC-2602-D2535Medutest2026-Q198.588.00—Supplier-supplied0PASS
AX-2026-043307CPC-2602-D2535Janoshik2026-Q198.167.72106.0Supplier-supplied0FAIL
AX-2026-043308CPC-2602-D2535Medutest2026-Q198.027.8697.1Supplier-supplied0FAIL
AX-2026-043309CPC-2602-D2535Medutest2026-Q198.938.32—Supplier-supplied0PASS
AX-2026-043310CPC-2602-D2535Janoshik2026-Q198.157.85—Supplier-supplied0FAIL
AX-2026-043311CPC-2602-D2535Kestrel2026-Q198.587.71—Supplier-supplied0PASS
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
Janoshik398.68, 98.16, 98.1598.1630min+0.0098.16
Nordanalyt198.1298.1235min+0.0298.10
Medutest498.28, 98.58, 98.02, 98.9398.4325min+0.0898.35
Kestrel198.5898.5815min+0.2498.34

This lot contributes 6 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)98.6898.68divergence +0.40 pp vs batch median
Total impurities (% area)1.321.32
Largest single impurity (% area)not stated0.93
Water (%)not stated7.52
Counter-ion (%)not statedN/A
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)not statednot determined
Method stated on certificateYES—column, 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
glutathione disulfide (GSSG, +305 Da)9 / 90.790.57–1.30
cysteinyl-glycine (−129 Da)9 / 90.160.11–0.27
γ-Glu-Cys (−57 Da)9 / 90.150.09–0.82
S-sulfonate adduct (+80 Da)9 / 90.120.07–0.22
Section 7

What this rollup does not establish