AX-2026-043616 · Semaglutide · WXT lot WXT-2512-F5211

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	99.61	% area	≥ 97.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.39	% area	≤ 3.0	PASS
Largest single impurity	RP-HPLC — des-His1 truncate (−137 Da)	0.16	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	4111.0524	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	4111.0520	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-0.1	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	83.34	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	83.01	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	17.67	mg	15 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	14.668	mg	15 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	97.8	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.10	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	11.29	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.27	%	—	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	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	3.21	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	17.26	min	17.29 ± 0.45 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.20	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	53,305	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-His1 truncate (−137 Da)	3.47	—	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 53,305, and skew follows the reported asymmetry factor of 1.20. 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 0.16 % impurity against a 99.61 % 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	17.26	4,841,355	99.61	—
2	des-His1 truncate (−137 Da)	16.20	7,776	0.16	-137.059
3	semaglutide dimer	20.72	6,804	0.14	+4111.052
4	tBu-protected residual (+56 Da)	19.17	2,430	0.05	+56.063
5	C18 diacid mono-ester	18.53	1,944	0.04	+14.016
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 4111.0520 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	686.1826	-0.0001	8.7
5+	823.2178	823.2177	-0.0001	52.4
4+	1028.7704	1028.7703	-0.0001	100.0
3+	1371.3581	1371.3579	-0.0002	54.1
2+	2056.5335	2056.5333	-0.0002	8.2

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	5.10
Counter-ion (TFA)	ion chromatography	11.29
Residual solvent + inorganic residue	estimated	0.27
Total peptide content	by difference	83.34
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)	99.51	99.61	divergence +0.20 pp vs batch median
Total impurities (% area)	0.49	0.39
Largest single impurity (% area)	not stated	0.16
Water (%)	4.5	5.10
Counter-ion (%)	5.9	11.29
Peptide content (%w/w)	89.0	83.34
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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 2 d) → assay. Submitter did not handle the vial.
Assay date: 24 Apr 2026
Submitted to the index: 07 May 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 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.

des_gly07 May 2026

At 99.61 % the deletion-sequence family is at or below the reporting threshold. On a sequence with a hindered coupling that is a statement about coupling efficiency, and a good one.

prep_hplc_cut07 May 2026

0.39 % total impurities on Semaglutide means the preparative fraction was cut narrow. That trades yield for purity, and the trade was made in the buyer's favour on this lot.

racemisation_ala07 May 2026

Epimerisation during activation produces a diastereomer that is mass-identical and only chromatographically separable. At this gradient length the separation exists, and 99.61 % is net of it.

Section 7

Related records

Same batch — lot WXT-2512-F5211 n=5

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043612	WXT-2512-F5211	Nordanalyt	2026-Q2	99.31	4.18	103.5	Buyer-sourced	1	MARGINAL
AX-2026-043613	WXT-2512-F5211	VendorInvestigate	2026-Q2	99.14	4.91	104.7	Buyer-sourced	2	FAIL
AX-2026-043614	WXT-2512-F5211	VendorInvestigate	2026-Q2	98.91	5.46	—	Buyer-sourced	1	MARGINAL
AX-2026-043615	WXT-2512-F5211	VendorInvestigate	2026-Q2	99.63	5.50	104.4	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Semaglutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042336	Homopeptide	HOMO-2604-X1993	Nordanalyt	2026-Q3	98.87	4.67	—	Buyer-sourced	PASS
AX-2026-041764	FGP	FGP-2602-M9916	Janoshik	2026-Q3	99.37	2.78	101.1	Buyer-sourced	PASS
AX-2026-042534	HJ	HJ-2608-C5744	Janoshik	2026-Q3	99.08	3.52	95.5	Buyer-sourced	PASS
AX-2026-042529	HJ	HJ-2608-C5744	Nordanalyt	2026-Q3	99.38	3.55	—	Buyer-sourced	PASS
AX-2026-042602	SWB	SWB-2602-X6980	Janoshik	2026-Q3	98.77	4.03	95.3	Supplier-supplied	PASS
AX-2026-041334	WWB	WWB-2606-N3192	Janoshik	2026-Q3	98.93	4.62	99.9	Buyer-sourced	PASS
AX-2026-041761	FGP	FGP-2602-M9916	Janoshik	2026-Q3	99.27	1.98	—	Buyer-sourced	PASS
AX-2026-043345	GL Biochem	GLBI-2602-U9408	Janoshik	2026-Q3	97.06	6.05	95.1	Buyer-sourced	PASS

Other recent WXT records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043651	Pramlintide	WXT-2603-D6459	PeptideMeter	2026-Q3	98.21	4.97	101.6	Buyer-sourced	1	MARGINAL
AX-2026-043531	Leuprolide	WXT-2604-K4483	Medutest	2026-Q3	99.00	5.03	—	Buyer-sourced	0	PASS
AX-2026-043561	Semaglutide	WXT-2604-C5135	Janoshik	2026-Q3	96.96	4.22	91.3	Buyer-sourced	0	FAIL
AX-2026-043627	L-Glutathione (reduced)	WXT-2605-B5720	Janoshik	2026-Q3	97.96	6.08	92.3	Buyer-sourced	1	FAIL
AX-2026-043564	Semaglutide	WXT-2604-C5135	Janoshik	2026-Q3	97.15	4.44	104.7	Buyer-sourced	0	PASS
AX-2026-043533	Leuprolide	WXT-2604-K4483	PeptideMeter	2026-Q3	99.89	4.94	—	Supplier-supplied	0	PASS
AX-2026-043624	L-Glutathione (reduced)	WXT-2605-B5720	Nordanalyt	2026-Q3	98.18	6.95	105.3	Buyer-sourced	2	FAIL
AX-2026-043556	Semaglutide	WXT-2604-C5135	PeptideMeter	2026-Q3	97.56	4.35	89.6	Buyer-sourced	1	MARGINAL