AX-2025-020043

L-Glutathione (reduced) · 1500 mg declared · Shanghai Wibson Biotechnology Co., Ltd. · lot SWB-2506-B7923

MARGINALMETHOD LIMITED

Report ID: AX-2025-020043
Compound: L-Glutathione (reduced)
Compound class: Short bioregulator peptides
Supplier: SWB — Shanghai Wibson Biotechnology Co., Ltd.
Batch / lot: SWB-2506-B7923
Declared label claim: 1500mg
Laboratory: PeptideMeter
Assay date: 28 Nov 2025
Submitted: 06 Dec 2025
Quarter: 2025-Q4
Submitter: i.dahlberg
Sample provenance: Buyer-sourced

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, 28 min gradient, 214 nm	99.39	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.61	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — S-sulfonate adduct (+80 Da)	0.44	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	307.0838	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	307.0833	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-1.6	ppm	± 20	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	10.59	%	≤ 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/	0.64	%	—	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 lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Faint haze, clearing on standing	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.93	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	3.99	min	4.02 ± 0.20 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.08	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	74,977	—	≥ 20,000	PASS
Resolution to nearest impurity	vs S-sulfonate adduct (+80 Da)	2.19	—	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, 28 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 74,977, and skew follows the reported asymmetry factor of 1.08. 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 0.44 % impurity against a 99.39 % 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	3.99	4,830,662	99.39	—
2	S-sulfonate adduct (+80 Da)	3.86	21,385	0.44	+79.957
3	glutathione disulfide (GSSG, +305 Da)	4.48	4,860	0.10	+304.984
4	cysteinyl-glycine (−129 Da)	3.77	1,944	0.04	-129.043
5	γ-Glu-Cys (−57 Da)	3.82	1,458	0.03	-57.021
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 3

Mass spectrum and identity

Theoretical monoisotopic mass 307.0838 Da, computed from C10H17N3O6S. All ppm figures on this site are against monoisotopic values — see why that matters.

Figure 2. ESI charge-state envelope, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 307.0833 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.

Charge	Theoretical m/z	Observed m/z	Δ m/z	Rel. abundance (%)
1+	308.0911	308.0906	-0.0005	100.0

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)	98.59	99.39	divergence -0.41 pp vs batch median
Total impurities (% area)	1.41	0.61
Largest single impurity (% area)	not stated	0.44
Water (%)	not stated	10.59
Counter-ion (%)	not stated	N/A
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	not stated	not determined
Method stated on certificate	NO	—	no method section — the result cannot be reconciled against any other

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: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → submitter (ambient, 20 d) → laboratory (hand-carried, 4 d) → assay.
Assay date: 28 Nov 2025
Submitted to the index: 06 Dec 2025
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: METHOD LIMITED

What this report does not establish

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 4

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.

lot_traceability06 Dec 2025

A retail vial at 99.39 % is worth more evidentially than a selected vial at a higher figure. That is the whole argument for recording provenance at all.

iso_audit06 Dec 2025

A certification says what a process is supposed to do. A retail vial says what it did. Both are worth having and only one of them is a measurement.

shipping_temp06 Dec 2025

A data logger in the box would upgrade this record further. Custody is documented; temperature history is inferred, and inference is weaker than measurement.

disulfide_fold06 Dec 2025

Reduced and scrambled forms are different problems with different causes and the report does not distinguish them. A non-reducing against reducing comparison would, and one laboratory in this index offers it.

Section 7

Related records

Same batch — lot SWB-2506-B7923 n=7

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020040	SWB-2506-B7923	Janoshik	2025-Q4	98.90	10.33	—	Supplier-supplied	1	MARGINAL
AX-2025-020041	SWB-2506-B7923	Janoshik	2025-Q4	99.00	10.33	105.2	Buyer-sourced	1	MARGINAL
AX-2025-020042	SWB-2506-B7923	Nordanalyt	2025-Q4	99.14	10.15	103.8	Buyer-sourced	1	MARGINAL
AX-2025-020044	SWB-2506-B7923	Janoshik	2025-Q4	99.05	10.02	98.6	Buyer-sourced	1	MARGINAL
AX-2025-020045	SWB-2506-B7923	Medutest	2025-Q4	98.59	10.70	99.2	Laboratory-retained	1	MARGINAL
AX-2025-020046	SWB-2506-B7923	Janoshik	2025-Q4	98.92	10.57	—	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

All L-Glutathione (reduced) records n=129
All SWB records n=204
All PeptideMeter records n=1116
All 2025-Q4 records n=762
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 SWB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042637	Semaglutide	SWB-2602-X7905	Janoshik	2026-Q3	98.37	4.26	102.9	Buyer-sourced	PASS
AX-2026-042645	Semaglutide	SWB-2602-X7905	Medutest	2026-Q3	98.48	4.52	95.2	Buyer-sourced	PASS
AX-2026-042642	Semaglutide	SWB-2602-X7905	PeptideMeter	2026-Q3	97.96	4.48	90.8	Buyer-sourced	PASS
AX-2026-042640	Semaglutide	SWB-2602-X7905	PeptideMeter	2026-Q3	98.55	4.29	—	Buyer-sourced	PASS
AX-2026-042638	Semaglutide	SWB-2602-X7905	Janoshik	2026-Q3	98.74	3.65	—	Buyer-sourced	PASS
AX-2026-042639	Semaglutide	SWB-2602-X7905	Janoshik	2026-Q3	98.77	4.21	—	Supplier-supplied	PASS
AX-2026-042641	Semaglutide	SWB-2602-X7905	Janoshik	2026-Q3	98.86	4.48	99.1	Buyer-sourced	PASS
AX-2026-042644	Semaglutide	SWB-2602-X7905	PeptideMeter	2026-Q3	98.76	3.57	97.7	Buyer-sourced	PASS