AssayIndex

KP-2508-J4716

Melanotan II · 10 mg declared · Zhuhai Kerui Biotechnology Co., Ltd. · manufactured 09 Aug 2025

CHARACTERISED
Lot code
KP-2508-J4716
Supplier
KP — Zhuhai Kerui Biotechnology Co., Ltd.
Compound
Melanotan II
Compound class
Melanocortin-receptor peptides
Declared label claim
10mg
Manufacture date
09 Aug 2025
Index quarter
2025-Q3
Independent assays
11
Laboratories involved
Janoshik, Kestrel, Medutest, PeptideMeter, VendorInvestigate
Provenance mix
Buyer-sourced ×2 · Supplier-supplied ×8 · Laboratory-retained ×1
Section 1

Reproducibility across independent tests

Every report below is an observation of the same physical material. What they disagree about is measurement; what they agree about is the lot. The size of the disagreement is compared against what the contributing laboratories' own repeatability figures predict.

Independent assays 11
Median purity 98.36% n=11
Spread (max − min) 1.21pp n=11
Standard deviation 0.358pp n=11
96.697.297.898.499.099.6100.2This lot (KP-2508-J4716)This lot (KP-2508-J4716): Q1 98.16, median 98.36, Q3 98.42, n=11outlier 97.61outlier 97.64outlier 98.82n=11All Melanotan IIAll Melanotan II: Q1 98.80, median 99.24, Q3 99.69, n=186outlier 96.85n=186 Purity (% area)
Figure 1. This lot's independent purity results against the whole Melanotan II record set in the index. The vertical line is the index acceptance specification for the melanocortin-receptor peptides class, 98.5 % area. A narrow box on the top row against a wide box on the bottom row is the ideal reading: it means the disagreement between lots is much larger than the disagreement within this one.
Section 2

Member reports 11

Every report the index holds on this lot. Each is a page carrying its own chromatogram, mass spectrum, mass balance, provenance and caveats.

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2025-020414KP-2508-J4716Janoshik2025-Q397.616.52Buyer-sourced1FAIL
AX-2025-020415KP-2508-J4716Kestrel2025-Q398.246.5296.3Supplier-supplied1FAIL
AX-2025-020416KP-2508-J4716Janoshik2025-Q398.436.74Supplier-supplied1FAIL
AX-2025-020417KP-2508-J4716Janoshik2025-Q398.506.4899.0Supplier-supplied1MARGINAL
AX-2025-020418KP-2508-J4716Medutest2025-Q398.406.6696.7Supplier-supplied1FAIL
AX-2025-020419KP-2508-J4716Janoshik2025-Q398.826.7688.9Supplier-supplied2MARGINAL
AX-2025-020420KP-2508-J4716PeptideMeter2025-Q398.096.5197.0Supplier-supplied1FAIL
AX-2025-020421KP-2508-J4716Janoshik2025-Q398.396.59Supplier-supplied1FAIL
AX-2025-020422KP-2508-J4716VendorInvestigate2025-Q397.646.74Buyer-sourced1FAIL
AX-2025-020423KP-2508-J4716Kestrel2025-Q398.296.7993.8Laboratory-retained1FAIL
AX-2025-020424KP-2508-J4716Janoshik2025-Q398.366.4790.8Supplier-supplied1FAIL
Section 3

By laboratory

Where more than one laboratory assayed this lot, the difference between them is a paired observation of their relative bias — the same material, the same time window, different instruments. Those pairs are what the index's bias estimates are built from.

LaboratoryReportsPurity results (% area)MedianGradientPublished bias (pp)Bias-adjusted
Janoshik697.61, 98.43, 98.50, 98.82, 98.39, 98.3698.4130min+0.0098.41
Kestrel298.24, 98.2998.2715min+0.2498.03
Medutest198.4098.4025min+0.0898.32
PeptideMeter198.0998.0928min-0.0598.14
VendorInvestigate197.6497.6432min-0.1197.75

This lot contributes 10 paired comparisons to the inter-lab analysis.

Section 4

The supplier's certificate for this lot

One number the supplier wrote, beside the median of the numbers other people measured on the same physical material. That comparison is only available because the index groups by lot.

FigureSupplier COAThis reportIndex note
Purity (% area)98.2197.61divergence -0.15 pp vs batch median
Total impurities (% area)not stated2.39
Largest single impurity (% area)not stated1.68
Water (%)5.56.52
Counter-ion (%)not stated4.67
Peptide content (%w/w)not statednot determined
Endotoxin (EU/mg)0.31not determined
Method stated on certificateYEScolumn, gradient and wavelength given
Section 5

Impurity fingerprint

The named impurities reported across this lot's assays, with how consistently each was seen. A fingerprint is what allows two lot numbers held by different companies to be identified as one bulk.

Named impurityReported inMedian % areaRange
oxidised Trp (+16 Da)11 / 111.110.06–1.68
des-acetyl MT-II (−42 Da)11 / 110.200.14–0.31
linear (open-lactam) precursor (+18 Da)11 / 110.270.17–0.86
MT-II dimer (head-to-tail)11 / 110.060.04–0.09
[L-Phe7]-diastereomer11 / 110.050.03–0.55
Section 7

What this rollup does not establish