AX-2026-043277

L-Glutathione (reduced) · 1500 mg declared · Chinese Peptide Company Co., Ltd. · lot CPC-2602-D1499

FAILPURITY ONLY

Report ID: AX-2026-043277
Compound: L-Glutathione (reduced)
Compound class: Short bioregulator peptides
Supplier: CPC — Chinese Peptide Company Co., Ltd.
Batch / lot: CPC-2602-D1499
Declared label claim: 1500mg
Laboratory: Nordanalyt Laboratories
Assay date: 09 Mar 2026
Submitted: 24 Mar 2026
Quarter: 2026-Q1
Submitter: k.varga
Sample provenance: Laboratory-retained

Section 1

Results

Measured against the index acceptance specification for the short bioregulator peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 35 min gradient, 214 nm	98.25	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.75	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — γ-Glu-Cys (−57 Da)	0.72	% area	≤ 1.00	PASS
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	7.94	%	≤ 12.0	PASS
Counter-ion	no ionisable counter-ion expected	N/A	—	not applicable	NOT TESTED
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.78	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	White to pale-yellow cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	6.85	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 35 min gradient	5.07	min	4.94 ± 0.20 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.07	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	67,175	—	≥ 20,000	PASS
Resolution to nearest impurity	vs S-sulfonate adduct (+80 Da)	2.04	—	no index criterion	REPORTED

Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

Figure 1. RP-HPLC trace, 35 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 67,175, and skew follows the reported asymmetry factor of 1.07. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.72 % impurity against a 98.25 % main peak is a line two pixels tall; the main peak runs off-scale there by design.

#	Peak	RT	Area (µV·s)	% area	Δ mass (Da)
1	L-Glutathione (reduced) — main peak	5.07	4,775,255	98.25	—
2	γ-Glu-Cys (−57 Da)	4.86	34,994	0.72	-57.021
3	glutathione disulfide (GSSG, +305 Da)	5.68	34,022	0.70	+304.984
4	S-sulfonate adduct (+80 Da)	4.91	9,235	0.19	+79.957
5	cysteinyl-glycine (−129 Da)	4.79	6,804	0.14	-129.043
Closure check — purity + Σ impurities				100.00	CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

Figure	Supplier COA	This report	Index note
Purity (% area)	98.48	98.25	divergence +0.12 pp vs batch median
Total impurities (% area)	not stated	1.75
Largest single impurity (% area)	not stated	0.72
Water (%)	6.9	7.94
Counter-ion (%)	not stated	N/A
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	0.48	not determined
Method stated on certificate	YES	—	column, gradient and wavelength given

Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance: Laboratory-retained
Evidentiary weight: Provenance documented, selection uncontrolled.
Chain of custody: Laboratory retained sample (−20 °C, 26 d since original receipt) → re-assay.
Assay date: 09 Mar 2026
Submitted to the index: 24 Mar 2026
Laboratory: Nordanalyt Laboratories, Uppsala, Sweden
Method basis: 35 min gradient · high-resolution MS
Verification status: PURITY ONLY

What this report does not establish

That the compound is the compound named. No identity confirmation was ordered on this submission. A purity figure describes chromatographic homogeneity of whatever eluted; it does not name it.
How much of the named compound is in the vial. Peptide content was not determined, so recovered mass cannot be calculated and the label claim cannot be checked.
That the material is free of bacterial endotoxin. Endotoxin was not measured. No chromatographic result bears on it.
That the material is sterile. Sterility was not tested.
That any other vial in the same lot has the same composition. One vial was tested. Within-lot vial-to-vial variation in this index has a median of 0.28 pp and a 90th percentile of 0.74 pp.
That any other lot from the same supplier has the same composition. Batch-to-batch variation is larger than within-batch variation for every supplier here.
That the material is suitable for administration to a human or an animal. These are research compounds. No result on this site is a safety assessment and the index takes no position on use.
That the material was manufactured by the supplier that sold it. Contract synthesis is normal in this market and twenty-nine batches in the index fingerprint to a bulk from a different company than the one named on the label.

Section 6

Annotations 3

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

ms_confirm24 Mar 2026

Mass confirms composition, not connectivity. On a disulfide-containing sequence that distinction is the entire question and no mass spectrometer answers it.

coa_reader24 Mar 2026

Purity and identity answer different questions and neither substitutes for the other. A 99 % pure sample of the wrong compound is 99 % pure.

esi_tof24 Mar 2026

Ordering identity on one vial in five would characterise a supplier's catalogue adequately at a fifth of the cost. Nobody does it systematically.

Section 7

Related records

Same batch — lot CPC-2602-D1499 n=7

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043272	CPC-2602-D1499	Janoshik	2026-Q1	98.50	8.64	102.5	Supplier-supplied	0	PASS
AX-2026-043273	CPC-2602-D1499	Medutest	2026-Q1	98.72	7.46	95.6	Buyer-sourced	0	PASS
AX-2026-043274	CPC-2602-D1499	Janoshik	2026-Q1	98.31	8.10	—	Buyer-sourced	0	FAIL
AX-2026-043275	CPC-2602-D1499	PeptideMeter	2026-Q1	98.36	8.00	88.5	Buyer-sourced	1	FAIL
AX-2026-043276	CPC-2602-D1499	Janoshik	2026-Q1	98.36	8.06	—	Buyer-sourced	0	FAIL
AX-2026-043278	CPC-2602-D1499	Janoshik	2026-Q1	98.23	7.31	93.2	Buyer-sourced	0	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All L-Glutathione (reduced) records n=129
All CPC records n=227
All Nordanalyt records n=545
All 2026-Q1 records n=806
L-Glutathione (reduced) by supplier
L-Glutathione (reduced) impurity profile

Other recent L-Glutathione (reduced) records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043429	WXT	WXT-2605-B3833	Nordanalyt	2026-Q3	98.48	6.58	96.9	Supplier-supplied	1	FAIL
AX-2026-043424	WXT	WXT-2605-B3833	PeptideMeter	2026-Q3	98.37	6.86	—	Buyer-sourced	0	FAIL
AX-2026-043166	GL Biochem	GLBI-2606-S7352	Janoshik	2026-Q3	99.01	8.84	105.4	Laboratory-retained	1	MARGINAL
AX-2026-043423	WXT	WXT-2605-B3833	Janoshik	2026-Q3	97.86	6.66	93.4	Buyer-sourced	0	FAIL
AX-2026-043426	WXT	WXT-2605-B3833	Kestrel	2026-Q3	98.83	6.32	—	Supplier-supplied	1	MARGINAL
AX-2026-043425	WXT	WXT-2605-B3833	Janoshik	2026-Q3	98.77	6.35	—	Supplier-supplied	1	MARGINAL
AX-2026-043431	WXT	WXT-2605-B3833	Nordanalyt	2026-Q3	97.94	6.18	—	Buyer-sourced	0	FAIL
AX-2026-043427	WXT	WXT-2605-B3833	Medutest	2026-Q3	97.67	6.08	—	Buyer-sourced	1	FAIL

Other recent CPC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043319	BPC-157	CPC-2602-W1610	Medutest	2026-Q3	98.82	2.88	103.5	Buyer-sourced	2	MARGINAL
AX-2026-043295	Liraglutide	CPC-2602-G9942	Janoshik	2026-Q3	97.34	5.17	106.3	Buyer-sourced	0	FAIL
AX-2026-043288	Tirzepatide	CPC-2607-L1516	Janoshik	2026-Q3	96.89	5.11	101.1	Laboratory-retained	0	FAIL
AX-2026-043327	N-Acetyl Semax Amide	CPC-2602-D1905	Nordanalyt	2026-Q3	99.05	5.67	90.6	Buyer-sourced	1	FAIL
AX-2026-043328	N-Acetyl Semax Amide	CPC-2602-D1905	Janoshik	2026-Q3	99.49	6.83	100.9	Supplier-supplied	0	PASS
AX-2026-043257	L-Carnosine	CPC-2603-G9615	VendorInvestigate	2026-Q3	98.20	10.41	102.2	Buyer-sourced	0	FAIL
AX-2026-043297	Liraglutide	CPC-2602-G9942	Janoshik	2026-Q3	97.01	4.95	103.5	Buyer-sourced	0	FAIL
AX-2026-043331	N-Acetyl Semax Amide	CPC-2602-D1905	Janoshik	2026-Q3	99.46	6.22	—	Supplier-supplied	0	PASS