AX-2026-043372 · Semaglutide · WXT lot WXT-2604-C3248

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, 28 min gradient, 214 nm	96.69	% area	≥ 97.0	FAIL
Total impurities	RP-HPLC, sum of reported peaks	3.31	% area	≤ 3.0	FAIL
Largest single impurity	RP-HPLC — des-AEEA semaglutide (−145 Da)	2.03	% area	≤ 1.00	FAIL
Identity — theoretical monoisotopic mass	calculated from molecular formula	4111.0524	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	4111.0750	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+5.5	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	87.34	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	84.45	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	17.12	mg	15 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	14.458	mg	15 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	96.4	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.22	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	8.11	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.33	%	—	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	3.39	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	17.11	min	17.29 ± 0.45 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.09	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	45,441	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Aib8]-diastereomer	0.68	—	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 45,441, and skew follows the reported asymmetry factor of 1.09. 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 2.03 % impurity against a 96.69 % 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	17.11	4,699,434	96.69	—
2	des-AEEA semaglutide (−145 Da)	16.34	98,664	2.03	-145.074
3	tBu-protected residual (+56 Da)	19.02	37,910	0.78	+56.063
4	C18 diacid mono-ester	18.38	11,665	0.24	+14.016
5	des-His1 truncate (−137 Da)	16.05	7,776	0.16	-137.059
6	semaglutide dimer	20.57	2,916	0.06	+4111.052
7	[D-Aib8]-diastereomer	16.89	1,944	0.04	0.000
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, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 4111.0750 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	686.1864	0.0037	8.6
5+	823.2178	823.2223	0.0045	54.4
4+	1028.7704	1028.7760	0.0056	100.0
3+	1371.3581	1371.3656	0.0075	50.9
2+	2056.5335	2056.5448	0.0113	8.4

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	4.22
Counter-ion (TFA)	ion chromatography	8.11
Residual solvent + inorganic residue	estimated	0.33
Total peptide content	by difference	87.34
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)	97.0	96.69	divergence -0.18 pp vs batch median
Total impurities (% area)	3.00	3.31
Largest single impurity (% area)	1.47	2.03
Water (%)	not stated	4.22
Counter-ion (%)	7.9	8.11
Peptide content (%w/w)	88.0	87.34
Endotoxin (EU/mg)	0.33	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: Laboratory-retained
Evidentiary weight: Provenance documented, selection uncontrolled.
Chain of custody: Laboratory retained sample (−20 °C, 20 d since original receipt) → re-assay.
Assay date: 16 Jul 2026
Submitted to the index: 08 Aug 2026
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

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.

area_percent08 Aug 2026

Area percent with assumed unit response factors gets less reliable as impurity content rises. At 3.31 % total impurities the response-factor assumption is worth about a tenth of a point, which is small next to the gap but not nothing.

aspartimide08 Aug 2026

A pair of satellites either side of the main peak at roughly equal levels is the aspartimide signature. Worth checking the named-impurity table before attributing 3.31 % to coupling efficiency.

lambda_28008 Aug 2026

Aromatic-selective detection at 280 nm would identify whether des-AEEA semaglutide (−145 Da) carries the chromophore. That distinguishes a truncation from a modification in about ten minutes of instrument time.

macrolactam08 Aug 2026

For any sequence closed head-to-side-chain, the uncyclised precursor differs by 18 Da and is trivially separable by mass. The envelope on this record shows nothing at that offset.

Section 7

Related records

Same batch — lot WXT-2604-C3248 n=12

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043368	WXT-2604-C3248	VendorInvestigate	2026-Q3	97.40	4.25	—	Buyer-sourced	1	MARGINAL
AX-2026-043369	WXT-2604-C3248	Nordanalyt	2026-Q3	97.38	3.86	—	Buyer-sourced	1	MARGINAL
AX-2026-043370	WXT-2604-C3248	Janoshik	2026-Q3	97.23	3.58	89.0	Buyer-sourced	2	MARGINAL
AX-2026-043371	WXT-2604-C3248	Janoshik	2026-Q3	97.16	4.39	93.5	Buyer-sourced	1	MARGINAL
AX-2026-043373	WXT-2604-C3248	Janoshik	2026-Q3	97.34	3.91	103.4	Supplier-supplied	1	MARGINAL
AX-2026-043374	WXT-2604-C3248	Janoshik	2026-Q3	97.00	3.56	—	Buyer-sourced	1	MARGINAL
AX-2026-043375	WXT-2604-C3248	PeptideMeter	2026-Q3	97.69	4.04	95.1	Supplier-supplied	1	MARGINAL
AX-2026-043376	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-043377	WXT-2604-C3248	PeptideMeter	2026-Q3	97.20	4.08	—	Buyer-sourced	1	MARGINAL
AX-2026-043378	WXT-2604-C3248	Janoshik	2026-Q3	97.09	3.73	102.7	Supplier-supplied	1	MARGINAL
AX-2026-043379	WXT-2604-C3248	VendorInvestigate	2026-Q3	96.58	3.78	—	Buyer-sourced	1	FAIL

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