AX-2025-020940 · Semaglutide · WXT lot WXT-2508-G2836

Section 1

Results

Measured against the index acceptance specification for the incretin analogues and co-agonists 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, 25 min gradient, 214 nm	98.86	% area	≥ 97.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.14	% area	≤ 3.0	PASS
Largest single impurity	RP-HPLC — des-His1 truncate (−137 Da)	0.78	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	4111.0524	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	4111.0676	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+3.7	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	85.32	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	84.35	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	3.18	mg	3 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	2.682	mg	3 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	89.4	%	90.0 – 110.0	FAIL
Water content	Karl Fischer, coulometric, duplicate	3.15	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	11.09	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.44	%	—	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 cake, partial shrinkage from vial wall	—	white to off-white intact cake	FAIL
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	3.91	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	15.57	min	15.60 ± 0.45 (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	54,782	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Aib8]-diastereomer	0.73	—	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, 25 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 54,782, 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 0.78 % impurity against a 98.86 % 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	Semaglutide — main peak	15.57	4,804,902	98.86	—
2	des-His1 truncate (−137 Da)	14.62	37,910	0.78	-137.059
3	[D-Aib8]-diastereomer	15.37	9,235	0.19	0.000
4	des-AEEA semaglutide (−145 Da)	14.89	4,374	0.09	-145.074
5	C18 diacid mono-ester	16.70	2,430	0.05	+14.016
6	Met(O) sulfoxide (+16 Da)	15.00	1,458	0.03	+15.995
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 4111.0524 Da, computed from C187H291N45O59. All ppm figures on this site are against monoisotopic values — see why that matters.

Figure 2. ESI charge-state envelope, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 4111.0676 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 (%)
6+	686.1827	686.1852	0.0025	9.0
5+	823.2178	823.2208	0.0030	62.0
4+	1028.7704	1028.7742	0.0038	100.0
3+	1371.3581	1371.3631	0.0050	55.7
2+	2056.5335	2056.5411	0.0076	8.8

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	3.15
Counter-ion (TFA)	ion chromatography	11.09
Residual solvent + inorganic residue	estimated	0.44
Total peptide content	by difference	85.32
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)	98.81	98.86	divergence +0.36 pp vs batch median
Total impurities (% area)	not stated	1.14
Largest single impurity (% area)	not stated	0.78
Water (%)	1.7	3.15
Counter-ion (%)	not stated	11.09
Peptide content (%w/w)	93.5	85.32
Endotoxin (EU/mg)	0.58	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, 27 d) → laboratory (courier, cold pack, 9 d) → assay.
Assay date: 28 Aug 2025
Submitted to the index: 16 Sep 2025
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-resolution MS
Verification status: IDENTITY CONSISTENT

What this report does not establish

That the compound is not a near-isobaric alternative. Identity was confirmed at unit mass resolution, which cannot exclude species differing by 1 or 2 Da. The specific alternatives not excluded are named in the identity block above.
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_confirm16 Sep 2025

+3.7 ppm at this mass is a clean identity confirmation. With retention at 15.57 min, Semaglutide is established as the species measured. Note what it does not exclude: a mass-identical diastereomer, which no mass measurement of any resolution can.

method_absent16 Sep 2025

A resolution figure without a stated column and gradient is uninterpretable. Both are on this record, which is why the figure is worth printing at all.

hplc_ola16 Sep 2025

Flow rate is the free variable most operators never touch. Halving it on an isocratic hold across the pair is a fifteen-minute experiment with a definitive answer.

Section 7

Related records

Same batch — lot WXT-2508-G2836 n=5

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020937	WXT-2508-G2836	Janoshik	2025-Q3	98.52	2.42	—	Laboratory-retained	0	PASS
AX-2025-020938	WXT-2508-G2836	VendorInvestigate	2025-Q3	98.28	2.90	—	Buyer-sourced	0	PASS
AX-2025-020939	WXT-2508-G2836	VendorInvestigate	2025-Q3	97.76	3.14	99.9	Buyer-sourced	1	FAIL
AX-2025-020941	WXT-2508-G2836	Janoshik	2025-Q3	98.45	2.88	97.3	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Semaglutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043376	WXT	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-042424	Homopeptide	HOMO-2604-X3806	PeptideMeter	2026-Q3	98.85	4.87	92.0	Buyer-sourced	0	PASS
AX-2026-041643	FGP	FGP-2602-M8547	Janoshik	2026-Q3	99.31	2.79	100.7	Buyer-sourced	0	PASS
AX-2026-041334	WWB	WWB-2606-N3192	Janoshik	2026-Q3	98.93	4.62	99.9	Buyer-sourced	0	PASS
AX-2026-042002	AMB	AMB-2607-N6274	VendorInvestigate	2026-Q3	98.23	6.37	97.1	Buyer-sourced	1	MARGINAL
AX-2026-041337	WWB	WWB-2606-N3192	Nordanalyt	2026-Q3	99.52	3.92	—	Buyer-sourced	0	PASS
AX-2026-042595	HJ	HJ-2608-C7002	Janoshik	2026-Q3	99.50	3.55	—	Buyer-sourced	1	MARGINAL
AX-2026-042217	TFC	TFC-2604-X9037	PeptideMeter	2026-Q3	98.95	4.61	96.9	Buyer-sourced	0	PASS

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