AX-2026-042172 · Melanotan II · JEEP lot JEEP-2604-R9103

Section 1

Results

Measured against the index acceptance specification for the melanocortin-receptor 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, 32 min gradient, 214 nm	99.72	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.28	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — linear (open-lactam) precursor (+18 Da)	0.18	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	1023.5402	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	1023.5385	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-1.7	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	89.83	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	89.58	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	11.80	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	10.570	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	105.7	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.39	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	3.91	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.87	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.39	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, 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, 32 min gradient	10.46	min	10.44 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.28	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	55,658	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [L-Phe7]-diastereomer	0.94	—	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, 32 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 55,658, and skew follows the reported asymmetry factor of 1.28. 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 0.18 % impurity against a 99.72 % 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	Melanotan II — main peak	10.46	4,846,701	99.72	—
2	linear (open-lactam) precursor (+18 Da)	9.67	8,749	0.18	+18.011
3	des-acetyl MT-II (−42 Da)	9.95	2,430	0.05	-42.011
4	[L-Phe7]-diastereomer	10.29	1,458	0.03	0.000
5	oxidised Trp (+16 Da)	10.08	972	0.02	+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 1023.5402 Da, computed from C50H69N15O9. 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 1023.5385 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 (%)
3+	342.1873	342.1868	-0.0005	7.8
2+	512.7774	512.7765	-0.0009	57.5
1+	1024.5475	1024.5458	-0.0017	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	5.39
Counter-ion (acetate)	ion chromatography	3.91
Residual solvent + inorganic residue	estimated	0.87
Total peptide content	by difference	89.83
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	99.72	divergence -0.36 pp vs batch median
Total impurities (% area)	0.86	0.28
Largest single impurity (% area)	not stated	0.18
Water (%)	not stated	5.39
Counter-ion (%)	9.1	3.91
Peptide content (%w/w)	86.8	89.83
Endotoxin (EU/mg)	not stated	0.39
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 → third-party forwarder (27 d) → laboratory (courier, cold pack, 2 d) → assay.
Assay date: 19 May 2026
Submitted to the index: 03 Jun 2026
Laboratory: VendorInvestigate, Riga, Latvia
Method basis: 32 min gradient · high-resolution MS
Verification status: VERIFIED

Section 6

Annotations 2

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.

diode_array03 Jun 2026

Photodiode-array spectral homogeneity across the main peak would convert 99.72 % from a good number into a checked one. It is a free measurement on any instrument that already has the detector.

ms_confirm03 Jun 2026

-1.7 ppm at this mass is a clean identity confirmation. With retention at 10.46 min, Melanotan II is established as the species measured. Note what it does not exclude: a mass-identical diastereomer, which no mass measurement of any resolution can.

Section 7

Related records

Same batch — lot JEEP-2604-R9103 n=13

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042164	JEEP-2604-R9103	Janoshik	2026-Q2	99.54	5.23	—	Buyer-sourced	1	MARGINAL
AX-2026-042165	JEEP-2604-R9103	Janoshik	2026-Q2	99.76	5.24	—	Buyer-sourced	0	PASS
AX-2026-042166	JEEP-2604-R9103	Janoshik	2026-Q2	99.40	4.75	—	Buyer-sourced	0	PASS
AX-2026-042167	JEEP-2604-R9103	Nordanalyt	2026-Q2	99.90	5.71	—	Laboratory-retained	0	PASS
AX-2026-042168	JEEP-2604-R9103	Nordanalyt	2026-Q2	99.40	5.71	—	Buyer-sourced	0	PASS
AX-2026-042169	JEEP-2604-R9103	Janoshik	2026-Q2	99.43	5.22	—	Buyer-sourced	0	PASS
AX-2026-042170	JEEP-2604-R9103	Medutest	2026-Q2	99.92	5.07	—	Buyer-sourced	0	PASS
AX-2026-042171	JEEP-2604-R9103	Kestrel	2026-Q2	99.59	5.11	—	Buyer-sourced	0	PASS
AX-2026-042173	JEEP-2604-R9103	Janoshik	2026-Q2	99.38	5.31	—	Buyer-sourced	0	PASS
AX-2026-042174	JEEP-2604-R9103	PeptideMeter	2026-Q2	99.22	5.42	—	Buyer-sourced	0	PASS
AX-2026-042175	JEEP-2604-R9103	Janoshik	2026-Q2	99.19	5.45	—	Buyer-sourced	0	PASS
AX-2026-042176	JEEP-2604-R9103	Janoshik	2026-Q2	99.50	4.88	105.3	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Melanotan II records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042757	GGPeps	GGPE-2603-P1474	Janoshik	2026-Q3	99.54	6.78	92.0	Buyer-sourced	0	PASS
AX-2026-042756	GGPeps	GGPE-2603-P1474	Nordanalyt	2026-Q3	99.17	7.04	—	Buyer-sourced	0	PASS
AX-2026-042755	GGPeps	GGPE-2603-P1474	Nordanalyt	2026-Q3	99.25	6.58	90.4	Buyer-sourced	0	PASS
AX-2026-042760	GGPeps	GGPE-2603-P1474	Medutest	2026-Q3	99.43	7.02	—	Buyer-sourced	0	PASS
AX-2026-042758	GGPeps	GGPE-2603-P1474	PeptideMeter	2026-Q3	99.23	6.96	—	Buyer-sourced	0	PASS
AX-2026-042759	GGPeps	GGPE-2603-P1474	Janoshik	2026-Q3	99.15	6.71	105.1	Buyer-sourced	0	PASS
AX-2026-042168	JEEP	JEEP-2604-R9103	Nordanalyt	2026-Q2	99.40	5.71	—	Buyer-sourced	0	PASS
AX-2026-042164	JEEP	JEEP-2604-R9103	Janoshik	2026-Q2	99.54	5.23	—	Buyer-sourced	1	MARGINAL

Other recent JEEP records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042177	Hexarelin	JEEP-2608-Y9547	Janoshik	2026-Q3	99.90	3.42	—	Buyer-sourced	0	PASS
AX-2026-042162	Semaglutide	JEEP-2607-X9091	Janoshik	2026-Q3	98.98	3.46	—	Laboratory-retained	1	MARGINAL
AX-2026-042127	TB-500	JEEP-2602-V8614	Medutest	2026-Q3	99.68	3.55	—	Buyer-sourced	1	FAIL
AX-2026-042123	TB-500	JEEP-2602-V8614	PeptideMeter	2026-Q3	99.93	3.80	—	Buyer-sourced	0	PASS
AX-2026-042124	TB-500	JEEP-2602-V8614	PeptideMeter	2026-Q3	99.91	3.37	104.9	Buyer-sourced	0	PASS
AX-2026-042178	Hexarelin	JEEP-2608-Y9547	VendorInvestigate	2026-Q3	99.68	4.03	—	Buyer-sourced	0	PASS
AX-2026-042163	Semaglutide	JEEP-2607-X9091	Nordanalyt	2026-Q3	99.46	4.52	—	Buyer-sourced	1	MARGINAL
AX-2026-042122	TB-500	JEEP-2602-V8614	PeptideMeter	2026-Q3	99.60	3.58	97.0	Buyer-sourced	0	PASS