AX-2025-021076 · Tirzepatide · WXT lot WXT-2411-F4668

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	98.11	% area	≥ 97.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.89	% area	≤ 3.0	PASS
Largest single impurity	RP-HPLC — Met(O) sulfoxide (+16 Da)	0.89	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	4810.4103	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	4810.3733	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-7.7	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	86.50	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	84.87	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	23.07	mg	20 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	19.580	mg	20 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	97.9	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.76	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	7.82	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.92	%	—	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	Off-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	4.07	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	16.72	min	16.81 ± 0.45 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.25	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	68,277	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-Aib2 analogue	1.11	—	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 68,277, and skew follows the reported asymmetry factor of 1.25. 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 0.89 % impurity against a 98.11 % 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	Tirzepatide — main peak	16.72	4,768,450	98.11	—
2	Met(O) sulfoxide (+16 Da)	16.10	43,257	0.89	+15.995
3	trifluoroacetyl adduct (+96 Da)	17.49	19,927	0.41	+95.982
4	des-Gly deletion (−57 Da)	16.21	17,011	0.35	-57.021
5	des-Aib2 analogue	16.43	7,776	0.16	-85.053
6	truncated (3-39)	15.49	2,430	0.05	-222.112
7	C20 diacid mono-amide	18.07	1,458	0.03	+0.984
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 4810.4103 Da, computed from C225H348N48O68. 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 4810.3733 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 (%)
7+	688.2087	688.2035	-0.0052	8.7
6+	802.7423	802.7362	-0.0061	57.6
5+	963.0893	963.0819	-0.0074	100.0
4+	1203.6099	1203.6006	-0.0093	59.1
3+	1604.4774	1604.4650	-0.0124	8.6

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	4.76
Counter-ion (TFA)	ion chromatography	7.82
Residual solvent + inorganic residue	estimated	0.92
Total peptide content	by difference	86.50
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)	98.5	98.11	divergence +0.07 pp vs batch median
Total impurities (% area)	1.50	1.89
Largest single impurity (% area)	1.04	0.89
Water (%)	3.7	4.76
Counter-ion (%)	not stated	7.82
Peptide content (%w/w)	91.5	86.50
Endotoxin (EU/mg)	0.17	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: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → submitter (2–8 °C, 15 d) → laboratory (courier, ambient, 11 d) → assay.
Assay date: 03 May 2025
Submitted to the index: 28 May 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

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 WXT-2411-F4668 n=12

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-021073	WXT-2411-F4668	Janoshik	2025-Q2	98.38	4.22	—	Buyer-sourced	2	MARGINAL
AX-2025-021074	WXT-2411-F4668	Kestrel	2025-Q2	99.13	5.08	—	Laboratory-retained	2	MARGINAL
AX-2025-021075	WXT-2411-F4668	Kestrel	2025-Q2	98.63	4.90	103.3	Supplier-supplied	2	MARGINAL
AX-2025-021077	WXT-2411-F4668	PeptideMeter	2025-Q2	97.64	4.90	100.5	Buyer-sourced	2	MARGINAL
AX-2025-021078	WXT-2411-F4668	Kestrel	2025-Q2	99.64	5.17	—	Supplier-supplied	2	MARGINAL
AX-2025-021079	WXT-2411-F4668	PeptideMeter	2025-Q2	98.48	5.32	103.0	Supplier-supplied	2	MARGINAL
AX-2025-021080	WXT-2411-F4668	Nordanalyt	2025-Q2	97.95	4.36	99.1	Laboratory-retained	3	FAIL
AX-2025-021081	WXT-2411-F4668	Janoshik	2025-Q2	98.09	4.67	101.7	Supplier-supplied	2	MARGINAL
AX-2025-021082	WXT-2411-F4668	Janoshik	2025-Q2	98.19	5.06	—	Supplier-supplied	2	MARGINAL
AX-2025-021083	WXT-2411-F4668	Janoshik	2025-Q2	98.60	4.85	98.9	Supplier-supplied	2	MARGINAL
AX-2025-021084	WXT-2411-F4668	Janoshik	2025-Q2	98.85	4.34	103.8	Supplier-supplied	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Tirzepatide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043106	KP	KP-2608-D5921	PeptideMeter	2026-Q3	98.90	5.45	105.4	Supplier-supplied	2	MARGINAL
AX-2026-041742	FGP	FGP-2603-L9714	Janoshik	2026-Q3	99.37	2.43	105.5	Supplier-supplied	1	MARGINAL
AX-2026-043108	KP	KP-2608-D5921	Janoshik	2026-Q3	99.70	5.45	—	Supplier-supplied	2	MARGINAL
AX-2026-041741	FGP	FGP-2603-L9714	PeptideMeter	2026-Q3	98.62	2.57	—	Supplier-supplied	1	MARGINAL
AX-2026-043100	KP	KP-2608-D5921	VendorInvestigate	2026-Q3	98.27	5.31	94.4	Buyer-sourced	2	MARGINAL
AX-2026-043322	CPC	CPC-2607-L2552	Janoshik	2026-Q3	96.79	4.88	96.1	Supplier-supplied	2	FAIL
AX-2026-043111	KP	KP-2608-D5921	PeptideMeter	2026-Q3	99.71	5.15	—	Supplier-supplied	2	MARGINAL
AX-2026-043321	CPC	CPC-2607-L2552	Kestrel	2026-Q3	97.84	5.34	—	Supplier-supplied	2	MARGINAL

Other recent WXT records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043488	Pramlintide	WXT-2603-D6052	Janoshik	2026-Q3	97.87	4.37	—	Supplier-supplied	1	MARGINAL
AX-2026-043406	Semaglutide	WXT-2604-C4728	Janoshik	2026-Q3	97.24	4.65	—	Supplier-supplied	1	MARGINAL
AX-2026-043421	Sermorelin	WXT-2608-P4867	Janoshik	2026-Q3	98.15	3.09	—	Supplier-supplied	0	PASS
AX-2026-043420	Sermorelin	WXT-2608-P4867	Medutest	2026-Q3	98.62	3.07	96.4	Supplier-supplied	0	PASS
AX-2026-043423	Sermorelin	WXT-2608-P4867	Janoshik	2026-Q3	98.28	3.86	98.5	Buyer-sourced	0	PASS
AX-2026-043401	Semaglutide	WXT-2604-C4728	Medutest	2026-Q3	97.70	4.78	91.5	Supplier-supplied	1	MARGINAL
AX-2026-043400	Semaglutide	WXT-2604-C4728	Nordanalyt	2026-Q3	96.86	4.11	106.4	Laboratory-retained	1	FAIL
AX-2026-043422	Sermorelin	WXT-2608-P4867	Medutest	2026-Q3	98.35	3.59	—	Supplier-supplied	1	MARGINAL