AX-2025-019684 · Melanotan II · TFC lot TFC-2410-R2237

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, 25 min gradient, 214 nm	99.33	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.67	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-acetyl MT-II (−42 Da)	0.25	% 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	88.15	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	87.56	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	10.96	mg	10 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	9.597	mg	10 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	96.0	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	5.55	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	5.39	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.91	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	1.30	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	Off-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	6.34	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	8.46	min	8.33 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.16	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	63,391	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [L-Phe7]-diastereomer	0.97	—	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, 25 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 63,391, and skew follows the reported asymmetry factor of 1.16. 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 0.25 % impurity against a 99.33 % 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	8.46	4,827,746	99.33	—
2	des-acetyl MT-II (−42 Da)	8.06	12,151	0.25	-42.011
3	linear (open-lactam) precursor (+18 Da)	7.84	11,179	0.23	+18.011
4	oxidised Trp (+16 Da)	8.16	5,346	0.11	+15.995
5	MT-II dimer (head-to-tail)	10.42	2,430	0.05	+1023.540
6	[L-Phe7]-diastereomer	8.33	1,458	0.03	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 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	5.55
Counter-ion (acetate)	ion chromatography	5.39
Residual solvent + inorganic residue	estimated	0.91
Total peptide content	by difference	88.15
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)	99.66	99.33	divergence +0.41 pp vs batch median
Total impurities (% area)	0.34	0.67
Largest single impurity (% area)	0.19	0.25
Water (%)	not stated	5.55
Counter-ion (%)	2.6	5.39
Peptide content (%w/w)	93.3	88.15
Endotoxin (EU/mg)	0.54	1.30
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: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → submitter (ambient, 28 d) → laboratory (hand-carried, 2 d) → assay.
Assay date: 22 Mar 2025
Submitted to the index: 08 Apr 2025
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-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 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.

retest_date08 Apr 2025

A retest date on the certificate would tell you what the supplier is actually asserting about stability. Purity at 99.33 % on assay day is a starting condition, not a shelf life.

sample_vs_retail08 Apr 2025

Where a supplier-supplied result on the same lot also exists, the pair is the informative object rather than either record alone. The batch page shows whether one does.

coa_template08 Apr 2025

The document that arrived with this order is on file and its fields are scored on the supplier's documentation rubric. That score describes what a buyer receives, which is the useful version.

Section 7

Related records

Same batch — lot TFC-2410-R2237 n=3

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-019685	TFC-2410-R2237	PeptideMeter	2025-Q1	99.25	6.00	93.5	Buyer-sourced	0	PASS
AX-2025-019686	TFC-2410-R2237	Janoshik	2025-Q1	99.11	5.31	100.9	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 TFC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042265	Humanin (HNG)	TFC-2605-U1300	PeptideMeter	2026-Q3	99.52	6.31	—	Buyer-sourced	0	PASS
AX-2026-042222	SS-31 (Elamipretide)	TFC-2607-R9099	VendorInvestigate	2026-Q3	99.46	5.41	102.6	Buyer-sourced	0	PASS
AX-2026-042236	Humanin (HNG)	TFC-2608-S9940	Nordanalyt	2026-Q3	98.64	1.80	—	Buyer-sourced	0	PASS
AX-2026-042282	Retatrutide	TFC-2608-J1156	Janoshik	2026-Q3	98.54	4.27	—	Buyer-sourced	0	PASS
AX-2026-042226	SS-31 (Elamipretide)	TFC-2607-R9099	Janoshik	2026-Q3	99.62	5.47	—	Buyer-sourced	0	PASS
AX-2026-042217	Semaglutide	TFC-2604-X9037	PeptideMeter	2026-Q3	98.95	4.61	96.9	Buyer-sourced	0	PASS
AX-2026-042339	Sermorelin	TFC-2605-Y2176	Kestrel	2026-Q3	99.93	4.14	—	Supplier-supplied	1	FAIL
AX-2026-042214	Semaglutide	TFC-2604-X9037	Kestrel	2026-Q3	99.87	4.66	103.1	Laboratory-retained	0	PASS