AX-2026-042960 · Retatrutide · KP lot KP-2604-N4308

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, 30 min gradient, 214 nm	98.81	% area	≥ 96.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.19	% area	≤ 3.5	PASS
Largest single impurity	RP-HPLC — retatrutide dimer	0.59	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	4728.4871	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	4728.4696	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-3.7	ppm	± 15	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	5.45	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	8.49	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.57	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	2.11	EU/mg	≤ 5.0	PASS
Sterility	membrane filtration, USP <71>, 14 d	No growth at 14 d	—	no growth	PASS
Appearance	visual, diffuse light, black and white background	White powder, no defined cake (melt-back)	—	white to off-white intact cake	FAIL
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	3.48	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	20.53	min	20.71 ± 0.50 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.11	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	61,318	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-Aib20 analogue	1.29	—	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, 30 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 61,318, and skew follows the reported asymmetry factor of 1.11. 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 0.59 % impurity against a 98.81 % 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	Retatrutide — main peak	20.53	4,802,472	98.81	—
2	retatrutide dimer	24.65	28,676	0.59	+4728.487
3	des-Aib20 analogue	20.09	13,609	0.28	-85.053
4	incomplete Fmoc removal (+222 Da)	22.94	10,693	0.22	+222.068
5	oxidised Trp (+16 Da)	19.87	2,916	0.06	+15.995
6	C18 diacid regioisomer	21.11	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 4728.4871 Da, computed from C221H342N46O68. 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 4728.4696 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+	676.5054	676.5029	-0.0025	8.7
6+	789.0885	789.0855	-0.0030	59.8
5+	946.7047	946.7012	-0.0035	100.0
4+	1183.1291	1183.1247	-0.0044	58.8
3+	1577.1696	1577.1638	-0.0058	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.

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)	99.0	98.81	divergence +0.44 pp vs batch median
Total impurities (% area)	1.00	1.19
Largest single impurity (% area)	0.58	0.59
Water (%)	4.7	5.45
Counter-ion (%)	8.3	8.49
Peptide content (%w/w)	86.4	not determined
Endotoxin (EU/mg)	not stated	2.11
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, 10 d) → assay. Submitter did not handle the vial.
Assay date: 14 Apr 2026
Submitted to the index: 29 Apr 2026
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

How much of the named compound is in the vial. Peptide content was not determined, so recovered mass cannot be calculated and the label claim cannot be checked.
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-2604-N4308 n=10

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042957	KP-2604-N4308	Janoshik	2026-Q2	98.15	4.87	96.8	Supplier-supplied	2	MARGINAL
AX-2026-042958	KP-2604-N4308	Medutest	2026-Q2	98.67	6.12	—	Laboratory-retained	2	MARGINAL
AX-2026-042959	KP-2604-N4308	Janoshik	2026-Q2	98.55	4.88	—	Supplier-supplied	2	MARGINAL
AX-2026-042961	KP-2604-N4308	Janoshik	2026-Q2	98.29	5.67	—	Buyer-sourced	2	MARGINAL
AX-2026-042962	KP-2604-N4308	PeptideMeter	2026-Q2	98.67	5.36	103.9	Supplier-supplied	2	MARGINAL
AX-2026-042963	KP-2604-N4308	Nordanalyt	2026-Q2	98.57	5.08	—	Supplier-supplied	2	MARGINAL
AX-2026-042964	KP-2604-N4308	Janoshik	2026-Q2	98.24	4.87	—	Buyer-sourced	2	MARGINAL
AX-2026-042965	KP-2604-N4308	Janoshik	2026-Q2	98.15	5.64	—	Supplier-supplied	2	MARGINAL
AX-2026-042966	KP-2604-N4308	VendorInvestigate	2026-Q2	98.59	5.46	106.2	Buyer-sourced	2	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Retatrutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043029	KP	KP-2607-H5219	Medutest	2026-Q3	95.45	5.71	—	Supplier-supplied	2	FAIL
AX-2026-043030	KP	KP-2607-H5219	Kestrel	2026-Q3	95.97	6.95	97.1	Supplier-supplied	2	FAIL
AX-2026-041453	QYB	QYB-2604-B5660	VendorInvestigate	2026-Q3	98.02	2.55	—	Buyer-sourced	1	MARGINAL
AX-2026-041454	QYB	QYB-2604-B5660	Janoshik	2026-Q3	98.84	2.77	—	Supplier-supplied	1	MARGINAL
AX-2026-041538	QYB	QYB-2602-G6308	Medutest	2026-Q3	98.50	2.85	—	Supplier-supplied	2	MARGINAL
AX-2026-041456	QYB	QYB-2604-B5660	Janoshik	2026-Q3	98.23	3.24	—	Supplier-supplied	1	MARGINAL
AX-2026-041452	QYB	QYB-2604-B5660	Nordanalyt	2026-Q3	98.50	3.36	—	Supplier-supplied	1	MARGINAL
AX-2026-043039	KP	KP-2607-H5219	Janoshik	2026-Q3	96.14	5.62	—	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