AX-2026-043423 · L-Glutathione (reduced) · WXT lot WXT-2605-B3833

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, 30 min gradient, 214 nm	97.86	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	2.14	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — cysteinyl-glycine (−129 Da)	1.04	% area	≤ 1.00	FAIL
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Total peptide content	by difference from the gravimetric mass balance	92.50	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	90.52	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	618.96	mg	600 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	560.283	mg	600 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	93.4	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	6.66	%	≤ 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/	0.84	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.85	EU/mg	≤ 5.0	PASS
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	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	6.38	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	4.17	min	4.28 ± 0.20 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.12	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	64,904	—	≥ 20,000	PASS
Resolution to nearest impurity	vs S-sulfonate adduct (+80 Da)	2.09	—	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, 30 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 64,904, and skew follows the reported asymmetry factor of 1.12. 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 1.04 % impurity against a 97.86 % 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	4.17	4,756,299	97.86	—
2	cysteinyl-glycine (−129 Da)	3.93	50,547	1.04	-129.043
3	γ-Glu-Cys (−57 Da)	3.99	30,620	0.63	-57.021
4	glutathione disulfide (GSSG, +305 Da)	4.69	16,039	0.33	+304.984
5	S-sulfonate adduct (+80 Da)	4.03	6,804	0.14	+79.957
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	6.66
Counter-ion	none expected	0.00
Residual solvent + inorganic residue	estimated	0.84
Total peptide content	by difference	92.50
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)	97.81	97.86	divergence -0.15 pp vs batch median
Total impurities (% area)	not stated	2.14
Largest single impurity (% area)	not stated	1.04
Water (%)	4.7	6.66
Counter-ion (%)	2.8	N/A
Peptide content (%w/w)	91.9	92.50
Endotoxin (EU/mg)	not stated	0.85
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: Domestic warehouse despatch → submitter (2–8 °C, 6 d) → laboratory (courier, cold pack, 5 d) → assay.
Assay date: 22 Aug 2026
Submitted to the index: 12 Sep 2026
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 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 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 2

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.

peak_integrator12 Sep 2026

Reporting threshold matters at this level. Peaks below threshold are excluded from the impurity total but included in the purity denominator, which biases 97.86 % upward by a systematic tenth or so. The gap here is larger than that.

RT_shift12 Sep 2026

Retention within the compound window is consistent with L-Glutathione (reduced) and consistent with several other things. It narrows the field; it does not close it.

Section 7

Related records

Same batch — lot WXT-2605-B3833 n=12

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043424	WXT-2605-B3833	PeptideMeter	2026-Q3	98.37	6.86	—	Buyer-sourced	0	FAIL
AX-2026-043425	WXT-2605-B3833	Janoshik	2026-Q3	98.77	6.35	—	Supplier-supplied	1	MARGINAL
AX-2026-043426	WXT-2605-B3833	Kestrel	2026-Q3	98.83	6.32	—	Supplier-supplied	1	MARGINAL
AX-2026-043427	WXT-2605-B3833	Medutest	2026-Q3	97.67	6.08	—	Buyer-sourced	1	FAIL
AX-2026-043428	WXT-2605-B3833	Janoshik	2026-Q3	97.97	6.13	106.8	Buyer-sourced	0	FAIL
AX-2026-043429	WXT-2605-B3833	Nordanalyt	2026-Q3	98.48	6.58	96.9	Supplier-supplied	1	FAIL
AX-2026-043430	WXT-2605-B3833	Medutest	2026-Q3	97.82	6.81	106.0	Buyer-sourced	0	FAIL
AX-2026-043431	WXT-2605-B3833	Nordanalyt	2026-Q3	97.94	6.18	—	Buyer-sourced	0	FAIL
AX-2026-043432	WXT-2605-B3833	Janoshik	2026-Q3	97.52	6.08	—	Buyer-sourced	0	FAIL
AX-2026-043433	WXT-2605-B3833	Janoshik	2026-Q3	98.53	6.45	—	Buyer-sourced	0	PASS
AX-2026-043434	WXT-2605-B3833	Janoshik	2026-Q3	97.95	5.85	96.1	Buyer-sourced	0	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All L-Glutathione (reduced) records n=129
All WXT records n=301
All Janoshik records n=2989
All 2026-Q3 records n=455
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-2026-043426	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
AX-2026-043165	GL Biochem	GLBI-2606-S7352	Medutest	2026-Q3	99.47	8.60	—	Supplier-supplied	1	MARGINAL

Other recent WXT records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043376	Semaglutide	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-043429	L-Glutathione (reduced)	WXT-2605-B3833	Nordanalyt	2026-Q3	98.48	6.58	96.9	Supplier-supplied	1	FAIL
AX-2026-043347	Leuprolide	WXT-2604-K2596	PeptideMeter	2026-Q3	99.16	5.99	93.6	Buyer-sourced	0	PASS
AX-2026-043353	Leuprolide	WXT-2604-K2596	Janoshik	2026-Q3	99.19	4.90	95.3	Laboratory-retained	0	PASS
AX-2026-043345	Leuprolide	WXT-2604-K2596	Janoshik	2026-Q3	98.93	5.28	—	Buyer-sourced	0	PASS
AX-2026-043424	L-Glutathione (reduced)	WXT-2605-B3833	PeptideMeter	2026-Q3	98.37	6.86	—	Buyer-sourced	0	FAIL
AX-2026-043374	Semaglutide	WXT-2604-C3248	Janoshik	2026-Q3	97.00	3.56	—	Buyer-sourced	1	MARGINAL
AX-2026-043377	Semaglutide	WXT-2604-C3248	PeptideMeter	2026-Q3	97.20	4.08	—	Buyer-sourced	1	MARGINAL