AX-2025-019874

L-Glutathione (reduced) · 1500 mg declared · Shanghai Wibson Biotechnology Co., Ltd. · lot SWB-2506-B5296

MARGINALMETHOD LIMITED

Report ID: AX-2025-019874
Compound: L-Glutathione (reduced)
Compound class: Short bioregulator peptides
Supplier: SWB — Shanghai Wibson Biotechnology Co., Ltd.
Batch / lot: SWB-2506-B5296
Declared label claim: 1500mg
Laboratory: PeptideMeter
Assay date: 15 Oct 2025
Submitted: 16 Oct 2025
Quarter: 2025-Q4
Submitter: re.chukwu
Sample provenance: Supplier-supplied

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	98.80	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.20	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — S-sulfonate adduct (+80 Da)	0.86	% area	≤ 1.00	PASS
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Total peptide content	by difference from the gravimetric mass balance	89.15	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	88.08	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	1823.19	mg	1500 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	1605.866	mg	1500 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	107.1	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	9.91	%	≤ 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/	0.94	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
Sterility	membrane filtration, USP <71>, 14 d	No growth at 14 d	—	no growth	PASS
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	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	6.89	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	4.14	min	4.02 ± 0.20 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.17	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	75,903	—	≥ 20,000	PASS
Resolution to nearest impurity	vs S-sulfonate adduct (+80 Da)	2.12	—	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 75,903, and skew follows the reported asymmetry factor of 1.17. 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 0.86 % impurity against a 98.80 % 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	4.14	4,801,986	98.80	—
2	S-sulfonate adduct (+80 Da)	4.01	41,799	0.86	+79.957
3	glutathione disulfide (GSSG, +305 Da)	4.63	9,721	0.20	+304.984
4	cysteinyl-glycine (−129 Da)	3.92	3,888	0.08	-129.043
5	γ-Glu-Cys (−57 Da)	3.97	2,916	0.06	-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 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.

Component	Determination	%w/w of cake
Water	Karl Fischer	9.91
Counter-ion	none expected	0.00
Residual solvent + inorganic residue	estimated	0.94
Total peptide content	by difference	89.15
Total		100.00 CLOSES

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)	98.96	98.80	divergence +0.17 pp vs batch median
Total impurities (% area)	1.04	1.20
Largest single impurity (% area)	0.58	0.86
Water (%)	not stated	9.91
Counter-ion (%)	4.4	N/A
Peptide content (%w/w)	91.5	89.15
Endotoxin (EU/mg)	not stated	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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 12 d) → assay. Submitter did not handle the vial.
Assay date: 15 Oct 2025
Submitted to the index: 16 Oct 2025
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: METHOD LIMITED

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.
That the material is free of bacterial endotoxin. Endotoxin was not measured. No chromatographic result bears on it.
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

No annotations on this record. Annotations are short signed technical comments from index contributors; see how to contribute.

Section 7

Related records

Same batch — lot SWB-2506-B5296 n=10

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-019869	SWB-2506-B5296	Janoshik	2025-Q4	98.90	10.66	—	Supplier-supplied	2	MARGINAL
AX-2025-019870	SWB-2506-B5296	Janoshik	2025-Q4	98.96	9.86	91.3	Supplier-supplied	2	MARGINAL
AX-2025-019871	SWB-2506-B5296	Medutest	2025-Q4	98.69	10.27	—	Supplier-supplied	2	MARGINAL
AX-2025-019872	SWB-2506-B5296	Kestrel	2025-Q4	98.77	9.96	—	Buyer-sourced	2	MARGINAL
AX-2025-019873	SWB-2506-B5296	PeptideMeter	2025-Q4	98.18	10.42	—	Supplier-supplied	2	FAIL
AX-2025-019875	SWB-2506-B5296	VendorInvestigate	2025-Q4	98.72	10.16	90.6	Buyer-sourced	2	MARGINAL
AX-2025-019876	SWB-2506-B5296	Kestrel	2025-Q4	99.79	10.37	95.9	Supplier-supplied	2	MARGINAL
AX-2026-042408	SWB-2506-B5296	Nordanalyt	2025-Q4	98.70	10.06	—	Supplier-supplied	2	MARGINAL
AX-2025-019877	SWB-2506-B5296	PeptideMeter	2025-Q4	99.25	9.67	—	Supplier-supplied	3	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

All L-Glutathione (reduced) records n=122
All SWB records n=317
All PeptideMeter records n=1107
All 2025-Q4 records n=883
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-2026-043166	GL Biochem	GLBI-2606-S7722	PeptideMeter	2026-Q3	99.26	8.52	107.1	Supplier-supplied	1	MARGINAL
AX-2026-043461	WXT	WXT-2605-B5313	PeptideMeter	2026-Q3	97.39	6.92	102.2	Supplier-supplied	0	FAIL
AX-2026-042932	MKM	MKM-2511-F2902	Janoshik	2026-Q2	98.57	8.41	92.9	Supplier-supplied	1	MARGINAL
AX-2026-043399	WXT	WXT-2512-P4300	PeptideMeter	2026-Q2	98.07	8.72	—	Supplier-supplied	1	FAIL
AX-2026-042337	HJ	HJ-2511-F3082	Janoshik	2026-Q2	99.93	7.58	—	Supplier-supplied	0	PASS
AX-2026-042930	MKM	MKM-2511-F2902	Janoshik	2026-Q2	98.42	7.82	97.4	Supplier-supplied	1	FAIL
AX-2026-042336	HJ	HJ-2511-F3082	Janoshik	2026-Q2	99.93	7.34	—	Supplier-supplied	0	PASS
AX-2026-042338	HJ	HJ-2511-F3082	Kestrel	2026-Q2	99.93	6.73	—	Supplier-supplied	0	PASS

Other recent SWB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042461	Kisspeptin-10	SWB-2603-D6238	Janoshik	2026-Q3	98.35	4.65	96.5	Supplier-supplied	3	FAIL
AX-2026-042479	Melanotan II	SWB-2603-A5707	Janoshik	2026-Q3	99.16	3.67	94.5	Supplier-supplied	1	MARGINAL
AX-2026-042481	Melanotan II	SWB-2603-A5707	Medutest	2026-Q3	98.95	3.37	90.8	Supplier-supplied	1	MARGINAL
AX-2026-042460	Kisspeptin-10	SWB-2603-D6238	Kestrel	2026-Q3	99.55	4.21	90.8	Supplier-supplied	3	MARGINAL
AX-2026-042483	Melanotan II	SWB-2603-A5707	Janoshik	2026-Q3	99.38	3.73	107.2	Supplier-supplied	1	MARGINAL
AX-2026-042398	Semaglutide	SWB-2602-X5278	Nordanalyt	2026-Q3	99.08	4.48	—	Supplier-supplied	1	MARGINAL
AX-2026-042399	Semaglutide	SWB-2602-X5278	Janoshik	2026-Q3	98.56	3.82	—	Supplier-supplied	1	MARGINAL
AX-2026-042499	BPC-157	SWB-2607-Y5787	Kestrel	2026-Q3	99.93	4.25	94.4	Supplier-supplied	0	PASS