AssayIndex

AX-2026-041459

Retatrutide · 12 mg declared · ChinaPeptides Co., Ltd. (QYAOBIO) · lot QYB-2604-B5660

MARGINALVERIFIED
Report ID
AX-2026-041459
Compound
Retatrutide
Compound class
Incretin analogues and co-agonists
Supplier
QYB — ChinaPeptides Co., Ltd. (QYAOBIO)
Batch / lot
QYB-2604-B5660
Declared label claim
12mg
Laboratory
VendorInvestigate
Assay date
30 Aug 2026
Submitted
25 Sep 2026
Quarter
2026-Q3
Submitter
Contributor #P-1187
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the incretin analogues and co-agonists class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 32 min gradient, 214 nm97.91% area≥ 96.5PASS
Total impuritiesRP-HPLC, sum of reported peaks2.09% area≤ 3.5PASS
Largest single impurityRP-HPLC — oxidised Trp (+16 Da)1.15% area≤ 1.00FAIL
Identity — theoretical monoisotopic masscalculated from molecular formula4728.4871Da—NOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)4728.4904Da—NOT TESTED
Mass accuracyobserved vs theoretical+0.7ppm± 15PASS
Total peptide contentby difference from the gravimetric mass balance89.63%w/w—NOT TESTED
Target-compound contenttotal peptide content × purity87.76%w/w—NOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen12.60mg12 mg declaredNOT TESTED
Recovered target peptidegross fill × target content11.058mg12 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim92.2%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate2.84%≤ 8.0PASS
Counter-ion (TFA)anion-exchange ion chromatography6.72%≤ 12.0PASS
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.81%—NOT TESTED
Endotoxinkinetic chromogenic LAL0.60EU/mg≤ 5.0PASS
Sterilitymembrane filtration, USP <71>, 14 dNo growth at 14 d—no growthPASS
Appearancevisual, diffuse light, black and white backgroundWhite lyophilised cake, intact—white to off-white intact cakePASS
Reconstitution clarityreconstituted per submitter procedureClear, colourless, no visible particulates—clear, no visible particulatesPASS
pH (reconstituted, 1 mg/mL)potentiometric, two-point calibration3.95—2.5 – 8.0PASS
Retention time (observed)RP-HPLC, 32 min gradient22.02min21.98 ± 0.50 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.12—0.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²55,228—≥ 20,000PASS
Resolution to nearest impurityvs [D-Aib2]-diastereomer0.61—no 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.

01141228334244565 Retatrutide22.02 min · 97.91 % 21.3224.59 same trace · ×50 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 05101520253035 Retention time (min) Response (mAU)
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 55,228, 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 1.15 % impurity against a 97.91 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1Retatrutide — main peak22.024,758,73097.91—
2oxidised Trp (+16 Da)21.3255,8941.15+15.995
3des-Aib20 analogue21.5528,1900.58-85.053
4[D-Aib2]-diastereomer21.7910,2070.210.000
5C18 diacid regioisomer22.643,8880.080.000
6aspartimide (−18 Da)22.781,9440.04-18.011
7incomplete Fmoc removal (+222 Da)24.591,4580.03+222.068
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 4728.4871 Da, computed from C221H342N46O68. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100550750950115013501550 [M+5H]5+946.71[M+4H]4+1183.13[M+6H]6+789.09 m/z Relative abundance (%)
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 4728.4904 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 (%)
7+676.5054676.50590.00058.7
6+789.0885789.08900.000552.1
5+946.7047946.70540.0007100.0
4+1183.12911183.12990.000855.5
3+1577.16961577.17070.00117.9
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 Fischer2.84
Counter-ion (TFA)ion chromatography6.72
Residual solvent + inorganic residueestimated0.81
Total peptide contentby difference89.63
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)99.1997.91divergence +0.61 pp vs batch median
Total impurities (% area)not stated2.09
Largest single impurity (% area)not stated1.15
Water (%)0.92.84
Counter-ion (%)not stated6.72
Peptide content (%w/w)94.389.63
Endotoxin (EU/mg)not stated0.60
Method stated on certificateYES—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
Domestic warehouse despatch → submitter (2–8 °C, 8 d) → laboratory (courier, cold pack, 6 d) → assay.
Assay date
30 Aug 2026
Submitted to the index
25 Sep 2026
Laboratory
VendorInvestigate, Riga, Latvia
Method basis
32 min gradient · high-resolution MS
Verification status
VERIFIED
Section 6

Annotations

No annotations on this record. Annotations are short signed technical comments from index contributors; see how to contribute.

Section 7

Related records

Same batch — lot QYB-2604-B5660 n=10

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041452QYB-2604-B5660Nordanalyt2026-Q398.503.36—Supplier-supplied1MARGINAL
AX-2026-041453QYB-2604-B5660VendorInvestigate2026-Q398.022.55—Buyer-sourced1MARGINAL
AX-2026-041454QYB-2604-B5660Janoshik2026-Q398.842.77—Supplier-supplied1MARGINAL
AX-2026-041455QYB-2604-B5660Nordanalyt2026-Q399.062.70—Supplier-supplied1MARGINAL
AX-2026-041456QYB-2604-B5660Janoshik2026-Q398.233.24—Supplier-supplied1MARGINAL
AX-2026-041457QYB-2604-B5660PeptideMeter2026-Q398.662.85102.2Supplier-supplied1MARGINAL
AX-2026-041458QYB-2604-B5660PeptideMeter2026-Q398.322.76—Supplier-supplied1MARGINAL
AX-2026-041460QYB-2604-B5660Nordanalyt2026-Q398.972.71—Supplier-supplied1MARGINAL
AX-2026-041461QYB-2604-B5660Janoshik2026-Q399.142.2997.1Supplier-supplied1MARGINAL

Cross-sections

Other recent Retatrutide records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043029KPKP-2607-H5219Medutest2026-Q395.455.71—Supplier-supplied2FAIL
AX-2026-043030KPKP-2607-H5219Kestrel2026-Q395.976.9597.1Supplier-supplied2FAIL
AX-2026-041453QYBQYB-2604-B5660VendorInvestigate2026-Q398.022.55—Buyer-sourced1MARGINAL
AX-2026-041454QYBQYB-2604-B5660Janoshik2026-Q398.842.77—Supplier-supplied1MARGINAL
AX-2026-041538QYBQYB-2602-G6308Medutest2026-Q398.502.85—Supplier-supplied2MARGINAL
AX-2026-041456QYBQYB-2604-B5660Janoshik2026-Q398.233.24—Supplier-supplied1MARGINAL
AX-2026-041452QYBQYB-2604-B5660Nordanalyt2026-Q398.503.36—Supplier-supplied1MARGINAL
AX-2026-043039KPKP-2607-H5219Janoshik2026-Q396.145.62—Supplier-supplied2FAIL
Other recent QYB records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041453RetatrutideQYB-2604-B5660VendorInvestigate2026-Q398.022.55—Buyer-sourced1MARGINAL
AX-2026-041454RetatrutideQYB-2604-B5660Janoshik2026-Q398.842.77—Supplier-supplied1MARGINAL
AX-2026-041538RetatrutideQYB-2602-G6308Medutest2026-Q398.502.85—Supplier-supplied2MARGINAL
AX-2026-041456RetatrutideQYB-2604-B5660Janoshik2026-Q398.233.24—Supplier-supplied1MARGINAL
AX-2026-041452RetatrutideQYB-2604-B5660Nordanalyt2026-Q398.503.36—Supplier-supplied1MARGINAL
AX-2026-041427IpamorelinQYB-2605-H4298Janoshik2026-Q399.934.12—Supplier-supplied0PASS
AX-2026-041488PT-141 (Bremelanotide)QYB-2607-L5615Janoshik2026-Q399.933.79—Supplier-supplied0PASS
AX-2026-041536RetatrutideQYB-2602-G6308Janoshik2026-Q398.052.92—Supplier-supplied2MARGINAL