AssayIndex

AX-2026-042714

GHK-Cu · 50 mg declared · Shanghai ERP Biotechnology Co., Ltd. · lot ERP-2601-F9816

MARGINALPARTIAL
Report ID
AX-2026-042714
Compound
GHK-Cu
Compound class
Tissue-repair and immunomodulatory peptides
Supplier
ERP — Shanghai ERP Biotechnology Co., Ltd.
Batch / lot
ERP-2601-F9816
Declared label claim
50mg
Laboratory
Kestrel Bioanalytical
Assay date
20 Apr 2026
Submitted
13 May 2026
Quarter
2026-Q2
Submitter
d.oyelaran
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the tissue-repair and immunomodulatory peptides class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 15 min gradient, 214 nm98.93% area≥ 97.0PASS
Total impuritiesRP-HPLC, sum of reported peaks1.07% area≤ 3.0PASS
Largest single impurityRP-HPLC — GHK-Cu 2:1 complex0.45% area≤ 1.00PASS
Identity — theoretical monoisotopic masscalculated from molecular formula401.1024DaNOT TESTED
Identity — observed monoisotopic massLC-MS, unit resolution (single quadrupole)401.1018DaNOT TESTED
Mass accuracyobserved vs theoretical-1.4ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance95.50%w/wNOT TESTED
Target-compound contenttotal peptide content × purity94.48%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen56.47mg50 mg declaredNOT TESTED
Recovered target peptidegross fill × target content53.353mg50 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim106.7%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate4.31%≤ 10.0PASS
Counter-ionno ionisable counter-ion expectedN/Anot applicableNOT TESTED
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.19%NOT TESTED
Endotoxinnot ordered on this submissionnot determined≤ 5.0NOT TESTED
Sterilitynot ordered on this submissionnot determinedno growthNOT TESTED
Appearancevisual, diffuse light, black and white backgroundWhite lyophilised cake, intactwhite to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulatesclear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration6.982.5 – 8.0PASS
Retention time (observed)RP-HPLC, 15 min gradient3.96min3.34 ± 0.25 (normalised)FAIL
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.140.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²57,697≥ 20,000PASS
Resolution to nearest impurityvs oxidised His (+16 Da)1.78no index criterionREPORTED
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.

06492129841947625967 GHK-Cu3.96 min · 98.93 % 4.27 same trace · ×100 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 048121620 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 15 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 57,697, and skew follows the reported asymmetry factor of 1.14. 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 0.45 % impurity against a 98.93 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1GHK-Cu — main peak3.964,808,30598.93
2GHK-Cu 2:1 complex4.2721,8710.45+277.145
3apo-GHK (copper-free, −62 Da)3.7218,9550.39-61.930
4Gly-His dipeptide (−128 Da)3.616,8040.14-128.095
5oxidised His (+16 Da)3.844,3740.09+15.995
Closure check — purity + Σ impurities 100.00CLOSES

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 401.1024 Da, computed from C14H22CuN6O4. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100350375400425450475 [M+1H]1+402.11 m/z Relative abundance (%)
Figure 2. ESI charge-state envelope, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 401.1018 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.
ChargeTheoretical m/zObserved m/zΔ m/zRel. abundance (%)
1+402.1097402.1091-0.0006100.0
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.

ComponentDetermination%w/w of cake
WaterKarl Fischer4.31
Counter-ionnone expected0.00
Residual solvent + inorganic residueestimated0.19
Total peptide contentby difference95.50
Total100.00 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.

FigureSupplier COAThis reportIndex note
Purity (% area)99.098.93divergence +0.35 pp vs batch median
Total impurities (% area)1.001.07
Largest single impurity (% area)0.390.45
Water (%)not stated4.31
Counter-ion (%)5.1N/A
Peptide content (%w/w)90.895.50
Endotoxin (EU/mg)not statednot determined
Method stated on certificateNOno 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, 1 d) → laboratory (hand-carried, 2 d) → assay.
Assay date
20 Apr 2026
Submitted to the index
13 May 2026
Laboratory
Kestrel Bioanalytical, Melbourne, Australia
Method basis
15 min gradient · unit-resolution MS
Verification status
PARTIAL
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.

mass_defect
Mass defect is where it should be for a peptide of this composition. Nothing in the impurity table has a defect inconsistent with its assignment either.
ppm_error
Instrument was evidently in calibration on the day. A run of results at this accuracy across a laboratory's sequence is the background against which an excursion becomes interpretable.
digit_preference
Rounding to the nearest half point loses about 0.25 pp of information in the worst case, which is inside the expanded uncertainty of the measurement anyway. The information loss is real and small.
Section 7

Related records

Same batch — lot ERP-2601-F9816 n=10

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042707ERP-2601-F9816Janoshik2026-Q298.534.7096.3Buyer-sourced1MARGINAL
AX-2026-042708ERP-2601-F9816Nordanalyt2026-Q298.883.8791.5Buyer-sourced1MARGINAL
AX-2026-042709ERP-2601-F9816PeptideMeter2026-Q298.653.9994.6Buyer-sourced1MARGINAL
AX-2026-042710ERP-2601-F9816Nordanalyt2026-Q298.654.2499.6Buyer-sourced1MARGINAL
AX-2026-042711ERP-2601-F9816Kestrel2026-Q298.533.8489.7Laboratory-retained2MARGINAL
AX-2026-042712ERP-2601-F9816PeptideMeter2026-Q298.483.08100.3Buyer-sourced1MARGINAL
AX-2026-042713ERP-2601-F9816VendorInvestigate2026-Q298.023.75Buyer-sourced2FAIL
AX-2026-042715ERP-2601-F9816Nordanalyt2026-Q298.653.9198.7Buyer-sourced1MARGINAL
AX-2026-042716ERP-2601-F9816PeptideMeter2026-Q298.804.3792.0Laboratory-retained1MARGINAL
Other recent GHK-Cu records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043160SSASSA-2604-V7731Janoshik2026-Q298.014.0291.8Buyer-sourced0PASS
AX-2026-043157SSASSA-2604-V7731Medutest2026-Q299.195.14Supplier-supplied0PASS
AX-2026-041251WWBWWB-2512-B1996PeptideMeter2026-Q299.435.87Buyer-sourced1MARGINAL
AX-2026-043249CPCCPC-2601-D1258Kestrel2026-Q299.506.96Supplier-supplied0PASS
AX-2026-043245CPCCPC-2601-D1258PeptideMeter2026-Q298.106.5795.0Supplier-supplied0PASS
AX-2026-041247WWBWWB-2512-B1996PeptideMeter2026-Q299.236.0988.8Buyer-sourced1MARGINAL
AX-2026-042708ERPERP-2601-F9816Nordanalyt2026-Q298.883.8791.5Buyer-sourced1MARGINAL
AX-2026-043154SSASSA-2604-V7731PeptideMeter2026-Q297.824.82101.6Buyer-sourced0PASS
Other recent ERP records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-042706SurvodutideERP-2605-E9865PeptideMeter2026-Q398.385.33103.5Buyer-sourced0PASS
AX-2026-042704TesamorelinERP-2604-W9463Janoshik2026-Q399.024.08Buyer-sourced1MARGINAL
AX-2026-042705SurvodutideERP-2605-E9865Janoshik2026-Q398.245.3692.3Buyer-sourced0PASS
AX-2026-042708GHK-CuERP-2601-F9816Nordanalyt2026-Q298.883.8791.5Buyer-sourced1MARGINAL
AX-2026-042694LiraglutideERP-2601-P8985Kestrel2026-Q299.254.35107.3Buyer-sourced1MARGINAL
AX-2026-042707GHK-CuERP-2601-F9816Janoshik2026-Q298.534.7096.3Buyer-sourced1MARGINAL
AX-2026-042711GHK-CuERP-2601-F9816Kestrel2026-Q298.533.8489.7Laboratory-retained2MARGINAL
AX-2026-042722TirzepatideERP-2512-T9616Medutest2026-Q299.182.07Buyer-sourced1MARGINAL