AX-2025-021236

Melanotan II · 10 mg declared · PolyPeptide Group (Hangzhou) Co., Ltd. · lot PPG-2408-L8298

PASSPURITY ONLY

Report ID: AX-2025-021236
Compound: Melanotan II
Compound class: Melanocortin-receptor peptides
Supplier: PPG — PolyPeptide Group (Hangzhou) Co., Ltd.
Batch / lot: PPG-2408-L8298
Declared label claim: 10mg
Laboratory: Janoshik Analytical
Assay date: 22 Dec 2024
Submitted: 17 Jan 2025
Quarter: 2024-Q4
Submitter: Contributor #T-8990
Sample provenance: Laboratory-retained

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, 30 min gradient, 214 nm	99.91	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.09	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — [L-Phe7]-diastereomer	0.07	% area	≤ 1.00	PASS
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Total peptide content	by difference from the gravimetric mass balance	89.12	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	89.04	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	10.50	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	9.349	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	93.5	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.44	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	5.55	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.89	%	—	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 with a single visible fibre	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.50	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	9.74	min	9.84 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.12	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	60,469	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [L-Phe7]-diastereomer	0.99	—	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 60,469, and skew follows the reported asymmetry factor of 1.12. 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 0.07 % impurity against a 99.91 % 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	9.74	4,855,936	99.91	—
2	[L-Phe7]-diastereomer	9.58	3,402	0.07	0.000
3	des-acetyl MT-II (−42 Da)	9.26	486	0.01	-42.011
4	linear (open-lactam) precursor (+18 Da)	9.00	486	0.01	+18.011
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 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	4.44
Counter-ion (acetate)	ion chromatography	5.55
Residual solvent + inorganic residue	estimated	0.89
Total peptide content	by difference	89.12
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)	99.82	99.91	divergence -0.10 pp vs batch median
Total impurities (% area)	0.18	0.09
Largest single impurity (% area)	not stated	0.07
Water (%)	4.4	4.44
Counter-ion (%)	3.0	5.55
Peptide content (%w/w)	92.0	89.12
Endotoxin (EU/mg)	1.54	not determined
Method stated on certificate	NO	—	no method section — the result cannot be reconciled against any other

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: Laboratory-retained
Evidentiary weight: Provenance documented, selection uncontrolled.
Chain of custody: Laboratory retained sample (−20 °C, 34 d since original receipt) → re-assay.
Assay date: 22 Dec 2024
Submitted to the index: 17 Jan 2025
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: PURITY ONLY

What this report does not establish

That the compound is the compound named. No identity confirmation was ordered on this submission. A purity figure describes chromatographic homogeneity of whatever eluted; it does not name it.
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 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.

wide_iqr17 Jan 2025

A single result at 99.91 % is one draw. What makes a supplier's process legible is the spread across its lots, and that is on the scorecard rather than here. This record is one good point in a distribution worth reading whole.

baseline_noise17 Jan 2025

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 99.91 % and it is not always met.

Section 7

Related records

Same batch — lot PPG-2408-L8298 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2024-005397	PPG-2408-L8298	Nordanalyt	2024-Q4	99.86	4.55	93.0	Buyer-sourced	0	PASS
AX-2025-021237	PPG-2408-L8298	VendorInvestigate	2024-Q4	99.78	4.32	91.4	Buyer-sourced	0	PASS
AX-2024-005398	PPG-2408-L8298	PeptideMeter	2024-Q4	99.93	4.89	99.5	Buyer-sourced	0	PASS
AX-2024-005399	PPG-2408-L8298	PeptideMeter	2024-Q4	99.93	4.81	101.4	Buyer-sourced	1	FAIL
AX-2024-005400	PPG-2408-L8298	PeptideMeter	2024-Q4	99.93	4.78	—	Buyer-sourced	0	PASS
AX-2024-005401	PPG-2408-L8298	PeptideMeter	2024-Q4	99.66	4.61	93.0	Buyer-sourced	0	PASS
AX-2024-005402	PPG-2408-L8298	Nordanalyt	2024-Q4	99.93	4.60	105.2	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 PPG records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043598	Tesamorelin	PPG-2608-A6835	Kestrel	2026-Q3	98.91	2.56	100.3	Buyer-sourced	1	FAIL
AX-2026-043597	Tesamorelin	PPG-2608-A6835	Janoshik	2026-Q3	98.54	1.15	—	Buyer-sourced	0	PASS
AX-2026-043596	Tesamorelin	PPG-2608-A6835	PeptideMeter	2026-Q3	98.74	1.83	105.1	Buyer-sourced	1	MARGINAL
AX-2026-043605	Retatrutide	PPG-2604-X7060	Janoshik	2026-Q2	98.17	4.29	99.7	Buyer-sourced	0	PASS
AX-2026-043601	Retatrutide	PPG-2604-X7060	Janoshik	2026-Q2	98.28	3.96	95.3	Buyer-sourced	0	PASS
AX-2026-043668	AOD-9604	PPG-2602-W8018	PeptideMeter	2026-Q2	99.47	3.06	—	Buyer-sourced	0	PASS
AX-2026-043670	AOD-9604	PPG-2602-W8018	PeptideMeter	2026-Q2	99.56	2.71	104.5	Buyer-sourced	0	PASS
AX-2026-043630	CJC-1295 (no DAC)	PPG-2512-D7211	Janoshik	2026-Q2	99.66	5.11	92.5	Buyer-sourced	0	PASS