AX-2026-042748 · Semaglutide · GGPeps lot GGPE-2603-W1490

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	99.80	% area	≥ 97.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.20	% area	≤ 3.0	PASS
Largest single impurity	RP-HPLC — des-AEEA semaglutide (−145 Da)	0.10	% 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)	4111.0676	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	2.66	%	≤ 8.0	PASS
Counter-ion (TFA)	anion-exchange ion chromatography	8.66	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.55	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.99	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 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	4.23	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	17.32	min	17.29 ± 0.45 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.06	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	78,940	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-AEEA semaglutide (−145 Da)	3.03	—	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 78,940, and skew follows the reported asymmetry factor of 1.06. 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 0.10 % impurity against a 99.80 % 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	17.32	4,850,589	99.80	—
2	des-AEEA semaglutide (−145 Da)	16.55	4,860	0.10	-145.074
3	des-His1 truncate (−137 Da)	16.26	2,430	0.05	-137.059
4	semaglutide dimer	20.78	2,430	0.05	+4111.052
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 4111.0676 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	686.1852	0.0025	8.8
5+	823.2178	823.2208	0.0030	49.4
4+	1028.7704	1028.7742	0.0038	100.0
3+	1371.3581	1371.3631	0.0050	53.2
2+	2056.5335	2056.5411	0.0076	7.6

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.

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)	99.85	99.80	divergence +0.07 pp vs batch median
Total impurities (% area)	0.15	0.20
Largest single impurity (% area)	0.07	0.10
Water (%)	3.1	2.66
Counter-ion (%)	not stated	8.66
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	0.72	0.99
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 (ambient, 34 d) → laboratory (hand-carried, 2 d) → assay.
Assay date: 21 May 2026
Submitted to the index: 29 May 2026
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 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 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.

plate_count29 May 2026

99.80 % is normalised area, so it is silent on how much peptide is in the vial. Content and water are the numbers that answer that, and both are on this record. Purity is the good news; content is the actionable news.

baseline_noise29 May 2026

Baseline on this trace is flat enough that the reporting threshold is doing real work rather than hiding peaks in noise. That is a precondition for believing 99.80 % and it is not always met.

ms_confirm29 May 2026

Mass, retention and impurity profile all agree on this record. Three independent constraints pointing the same way is the strongest identity evidence the index publishes.

Section 7

Related records

Same batch — lot GGPE-2603-W1490 n=3

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042747	GGPE-2603-W1490	VendorInvestigate	2026-Q2	99.21	3.35	102.6	Buyer-sourced	0	PASS
AX-2026-042749	GGPE-2603-W1490	Medutest	2026-Q2	99.78	3.39	103.2	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Semaglutide records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043376	WXT	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-042424	Homopeptide	HOMO-2604-X3806	PeptideMeter	2026-Q3	98.85	4.87	92.0	Buyer-sourced	0	PASS
AX-2026-041643	FGP	FGP-2602-M8547	Janoshik	2026-Q3	99.31	2.79	100.7	Buyer-sourced	0	PASS
AX-2026-041334	WWB	WWB-2606-N3192	Janoshik	2026-Q3	98.93	4.62	99.9	Buyer-sourced	0	PASS
AX-2026-042002	AMB	AMB-2607-N6274	VendorInvestigate	2026-Q3	98.23	6.37	97.1	Buyer-sourced	1	MARGINAL
AX-2026-041337	WWB	WWB-2606-N3192	Nordanalyt	2026-Q3	99.52	3.92	—	Buyer-sourced	0	PASS
AX-2026-042595	HJ	HJ-2608-C7002	Janoshik	2026-Q3	99.50	3.55	—	Buyer-sourced	1	MARGINAL
AX-2026-042217	TFC	TFC-2604-X9037	PeptideMeter	2026-Q3	98.95	4.61	96.9	Buyer-sourced	0	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