AX-2026-043071 · Epitalon · KP lot KP-2508-Y5329

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, 25 min gradient, 214 nm	98.25	% area	≥ 99.0	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.75	% area	≤ 1.0	FAIL
Largest single impurity	RP-HPLC — Ala-Glu-Asp tripeptide (−57 Da)	0.90	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	390.1387	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	390.1361	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-6.7	ppm	± 20	PASS
Total peptide content	by difference from the gravimetric mass balance	78.86	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	77.48	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	23.83	mg	20 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	18.463	mg	20 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	92.3	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	8.64	%	≤ 12.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	12.29	%	≤ 10.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.21	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.30	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	Off-white lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear with a single visible fibre	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.42	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	3.89	min	3.91 ± 0.20 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.14	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	69,332	—	≥ 20,000	PASS
Resolution to nearest impurity	vs β-Asp isomer	1.38	—	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 69,332, and skew follows the reported asymmetry factor of 1.14. 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 0.90 % impurity against a 98.25 % 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	Epitalon — main peak	3.89	4,775,255	98.25	—
2	Ala-Glu-Asp tripeptide (−57 Da)	3.72	43,743	0.90	-57.021
3	aspartimide (−18 Da)	3.99	17,011	0.35	-18.011
4	diketopiperazine (−18 Da)	4.02	13,609	0.28	-18.011
5	β-Asp isomer	3.81	10,693	0.22	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 390.1387 Da, computed from C14H22N4O9. 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 390.1361 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 (%)
1+	391.1460	391.1434	-0.0026	100.0

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	8.64
Counter-ion (acetate)	ion chromatography	12.29
Residual solvent + inorganic residue	estimated	0.21
Total peptide content	by difference	78.86
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)	99.14	98.25	divergence +0.92 pp vs batch median
Total impurities (% area)	0.86	1.75
Largest single impurity (% area)	0.38	0.90
Water (%)	6.9	8.64
Counter-ion (%)	not stated	12.29
Peptide content (%w/w)	88.3	78.86
Endotoxin (EU/mg)	not stated	0.30
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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 8 d) → assay. Submitter did not handle the vial.
Assay date: 17 Mar 2026
Submitted to the index: 24 Mar 2026
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-resolution MS
Verification status: METHOD LIMITED

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 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 KP-2508-Y5329 n=9

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043063	KP-2508-Y5329	Medutest	2026-Q1	98.22	8.15	—	Buyer-sourced	1	FAIL
AX-2026-043064	KP-2508-Y5329	Janoshik	2026-Q1	98.06	8.31	100.4	Laboratory-retained	0	FAIL
AX-2026-043065	KP-2508-Y5329	PeptideMeter	2026-Q1	98.00	8.22	—	Supplier-supplied	1	FAIL
AX-2026-043066	KP-2508-Y5329	Medutest	2026-Q1	98.68	8.10	—	Supplier-supplied	0	FAIL
AX-2026-043067	KP-2508-Y5329	VendorInvestigate	2026-Q1	98.22	7.97	100.7	Buyer-sourced	0	FAIL
AX-2026-043068	KP-2508-Y5329	VendorInvestigate	2026-Q1	97.28	7.81	91.9	Buyer-sourced	0	FAIL
AX-2026-043069	KP-2508-Y5329	VendorInvestigate	2026-Q1	97.70	7.91	—	Buyer-sourced	0	FAIL
AX-2026-043070	KP-2508-Y5329	PeptideMeter	2026-Q1	98.33	8.14	—	Supplier-supplied	1	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Epitalon records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043099	KP	KP-2512-R5829	PeptideMeter	2026-Q2	98.33	6.52	94.5	Supplier-supplied	2	FAIL
AX-2026-042209	Homopeptide	HOMO-2512-A1223	Janoshik	2026-Q2	99.93	7.83	100.3	Supplier-supplied	0	FAIL
AX-2026-042208	Homopeptide	HOMO-2512-A1223	PeptideMeter	2026-Q2	99.36	7.93	102.7	Supplier-supplied	0	FAIL
AX-2026-043098	KP	KP-2512-R5829	Janoshik	2026-Q2	97.71	6.99	—	Supplier-supplied	2	FAIL
AX-2026-041270	WWB	WWB-2602-G2822	Janoshik	2026-Q2	99.75	6.69	88.9	Supplier-supplied	1	MARGINAL
AX-2026-043097	KP	KP-2512-R5829	Janoshik	2026-Q2	98.00	6.74	91.6	Supplier-supplied	2	FAIL
AX-2026-043096	KP	KP-2512-R5829	Medutest	2026-Q2	97.61	6.38	97.0	Buyer-sourced	3	FAIL
AX-2026-043095	KP	KP-2512-R5829	Janoshik	2026-Q2	97.68	6.82	—	Supplier-supplied	2	FAIL

Other recent KP records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043029	Retatrutide	KP-2607-H5219	Medutest	2026-Q3	95.45	5.71	—	Supplier-supplied	2	FAIL
AX-2026-043030	Retatrutide	KP-2607-H5219	Kestrel	2026-Q3	95.97	6.95	97.1	Supplier-supplied	2	FAIL
AX-2026-043106	Tirzepatide	KP-2608-D5921	PeptideMeter	2026-Q3	98.90	5.45	105.4	Supplier-supplied	2	MARGINAL
AX-2026-043108	Tirzepatide	KP-2608-D5921	Janoshik	2026-Q3	99.70	5.45	—	Supplier-supplied	2	MARGINAL
AX-2026-043039	Retatrutide	KP-2607-H5219	Janoshik	2026-Q3	96.14	5.62	—	Supplier-supplied	2	FAIL
AX-2026-043100	Tirzepatide	KP-2608-D5921	VendorInvestigate	2026-Q3	98.27	5.31	94.4	Buyer-sourced	2	MARGINAL
AX-2026-043090	Ipamorelin	KP-2606-D5887	Janoshik	2026-Q3	98.18	3.07	101.2	Laboratory-retained	1	FAIL
AX-2026-043028	Retatrutide	KP-2607-H5219	Janoshik	2026-Q3	96.52	6.09	—	Supplier-supplied	2	MARGINAL