AX-2025-020241 · Retatrutide · GGPeps lot GGPE-2508-E1731

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	97.45	% area	≥ 96.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	2.55	% area	≤ 3.5	PASS
Largest single impurity	RP-HPLC — des-Aib20 analogue	1.07	% area	≤ 1.00	FAIL
Identity — theoretical monoisotopic mass	calculated from molecular formula	4728.4871	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	4728.3561	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-27.7	ppm	± 15	FAIL
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	2.83	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	9.95	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.38	%	—	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 after 90 s gentle swirling, no particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.03	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	20.74	min	20.71 ± 0.50 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.29	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	56,089	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Aib2]-diastereomer	0.61	—	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 56,089, and skew follows the reported asymmetry factor of 1.29. 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 1.07 % impurity against a 97.45 % 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	20.74	4,736,372	97.45	—
2	des-Aib20 analogue	20.30	52,005	1.07	-85.053
3	retatrutide dimer	24.86	46,173	0.95	+4728.487
4	incomplete Fmoc removal (+222 Da)	23.15	12,637	0.26	+222.068
5	[D-Aib2]-diastereomer	20.52	8,749	0.18	0.000
6	C18 diacid regioisomer	21.32	2,430	0.05	0.000
7	oxidised Trp (+16 Da)	20.08	1,944	0.04	+15.995
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 4728.3561 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	676.4867	-0.0187	7.6
6+	789.0885	789.0666	-0.0219	49.5
5+	946.7047	946.6785	-0.0262	100.0
4+	1183.1291	1183.0963	-0.0328	53.1
3+	1577.1696	1577.1260	-0.0436	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)	98.02	97.45	divergence +0.04 pp vs batch median
Total impurities (% area)	1.98	2.55
Largest single impurity (% area)	1.46	1.07
Water (%)	not stated	2.83
Counter-ion (%)	not stated	9.95
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	not stated	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 (−20 °C, 11 d) → laboratory (courier, dry ice, 8 d) → assay.
Assay date: 30 Jul 2025
Submitted to the index: 06 Aug 2025
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: IDENTITY CONSISTENT

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 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.

isotope_cluster06 Aug 2025

Check whether the reported mass is monoisotopic or average. At this molecular weight the two differ by considerably more than the -27.7 ppm being flagged, and confusing them is the single commonest cause of an apparent mass error on a large peptide.

mass_defect06 Aug 2025

If the assignment is shifted by one charge state the error resolves. Confirm the deconvolution before treating -27.7 ppm as a real discrepancy about the material.

ppm_error06 Aug 2025

The distribution of ppm error by instrument class in this index is wide enough that a single figure like -27.7 ppm carries little on its own. What carries is whether the same instrument produced similar excursions on adjacent runs, and the laboratory page has that.

Section 7

Related records

Same batch — lot GGPE-2508-E1731 n=10

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020234	GGPE-2508-E1731	Janoshik	2025-Q3	97.46	2.13	107.1	Buyer-sourced	0	PASS
AX-2025-020235	GGPE-2508-E1731	Nordanalyt	2025-Q3	97.69	2.63	96.3	Buyer-sourced	0	PASS
AX-2025-020236	GGPE-2508-E1731	Janoshik	2025-Q3	97.79	3.06	97.7	Buyer-sourced	0	PASS
AX-2025-020237	GGPE-2508-E1731	Kestrel	2025-Q3	98.61	1.92	106.7	Buyer-sourced	1	FAIL
AX-2025-020238	GGPE-2508-E1731	Nordanalyt	2025-Q3	98.03	3.20	90.4	Buyer-sourced	0	PASS
AX-2025-020239	GGPE-2508-E1731	Medutest	2025-Q3	97.93	2.18	88.8	Buyer-sourced	1	MARGINAL
AX-2025-020240	GGPE-2508-E1731	Medutest	2025-Q3	98.70	2.30	—	Supplier-supplied	0	PASS
AX-2025-020242	GGPE-2508-E1731	Janoshik	2025-Q3	98.37	2.28	97.3	Supplier-supplied	0	PASS
AX-2025-020243	GGPE-2508-E1731	Medutest	2025-Q3	98.12	2.82	93.6	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Retatrutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042437	Homopeptide	HOMO-2605-V4718	Nordanalyt	2026-Q3	98.68	3.67	102.8	Buyer-sourced	PASS
AX-2026-043095	KP	KP-2607-H5774	Janoshik	2026-Q3	95.81	5.48	105.2	Buyer-sourced	FAIL
AX-2026-042282	TFC	TFC-2608-J1156	Janoshik	2026-Q3	98.54	4.27	—	Buyer-sourced	PASS
AX-2026-043094	KP	KP-2607-H5774	PeptideMeter	2026-Q3	96.32	6.40	—	Buyer-sourced	FAIL
AX-2026-042441	Homopeptide	HOMO-2605-V4718	Medutest	2026-Q3	98.93	4.22	—	Buyer-sourced	PASS
AX-2026-041427	QYB	QYB-2604-B4920	PeptideMeter	2026-Q3	97.93	2.45	101.7	Buyer-sourced	PASS
AX-2026-041786	ASY	ASY-{CAT}-2288	VendorInvestigate	2026-Q3	98.78	6.59	—	Buyer-sourced	PASS
AX-2026-041428	QYB	QYB-2604-B4920	Janoshik	2026-Q3	98.35	3.20	—	Laboratory-retained	PASS

Other recent GGPeps records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-042784	CJC-1295 (no DAC)	GGPE-2606-E1234	Medutest	2026-Q3	98.27	4.55	—	Buyer-sourced	PASS
AX-2026-042786	CJC-1295 (no DAC)	GGPE-2606-E1234	Janoshik	2026-Q3	98.22	3.77	—	Buyer-sourced	PASS
AX-2026-042858	Selank	GGPE-2603-J2447	VendorInvestigate	2026-Q3	98.87	8.85	99.4	Buyer-sourced	FAIL
AX-2026-042783	CJC-1295 (no DAC)	GGPE-2606-E1234	Janoshik	2026-Q3	98.22	4.45	90.6	Buyer-sourced	PASS
AX-2026-042757	Melanotan II	GGPE-2603-P1474	Janoshik	2026-Q3	99.54	6.78	92.0	Buyer-sourced	PASS
AX-2026-042785	CJC-1295 (no DAC)	GGPE-2606-E1234	PeptideMeter	2026-Q3	97.70	4.64	91.4	Buyer-sourced	FAIL
AX-2026-042756	Melanotan II	GGPE-2603-P1474	Nordanalyt	2026-Q3	99.17	7.04	—	Buyer-sourced	PASS
AX-2026-042755	Melanotan II	GGPE-2603-P1474	Nordanalyt	2026-Q3	99.25	6.58	90.4	Buyer-sourced	PASS