AssayIndex

AX-2026-043698

MK-677 (Ibutamoren mesylate) · 500 mg declared · Bachem Holding (Suzhou) Co., Ltd. · lot BCH-2601-G7291

FAILVERIFIED
Report ID
AX-2026-043698
Compound
MK-677 (Ibutamoren mesylate)
Compound class
Non-peptide adjuncts
Supplier
BCH — Bachem Holding (Suzhou) Co., Ltd.
Batch / lot
BCH-2601-G7291
Declared label claim
500mg
Laboratory
Nordanalyt Laboratories
Assay date
22 Feb 2026
Submitted
05 Mar 2026
Quarter
2026-Q1
Submitter
r.wojcik
Sample provenance
Buyer-sourced
Section 1

Results

Measured against the index acceptance specification for the non-peptide adjuncts class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

ParameterMethodResultUnitIndex spec
PurityRP-HPLC, 35 min gradient, 214 nm97.67% area≥ 98.5FAIL
Total impuritiesRP-HPLC, sum of reported peaks2.33% area≤ 1.5FAIL
Largest single impurityRP-HPLC — O-desmethyl metabolite analogue (−14 Da)1.05% area≤ 1.00FAIL
Identity — theoretical monoisotopic masscalculated from molecular formula624.2181DaNOT TESTED
Identity — observed monoisotopic massLC-MS, high resolution (ESI-TOF/QTOF)624.2202DaNOT TESTED
Mass accuracyobserved vs theoretical+3.3ppm± 10PASS
Total peptide contentby difference from the gravimetric mass balance80.21%w/wNOT TESTED
Target-compound contenttotal peptide content × purity78.34%w/wNOT TESTED
Gross fill (as weighed)five-place balance, under nitrogen623.36mg500 mg declaredNOT TESTED
Recovered target peptidegross fill × target content488.340mg500 mg claimNOT TESTED
Recovery against label claimrecovered ÷ claim97.7%90.0 – 110.0PASS
Water contentKarl Fischer, coulometric, duplicate3.95%≤ 10.0PASS
Counter-ion (mesylate)anion-exchange ion chromatography14.85%≤ 12.0FAIL
Residual solvent + inorganic residueestimated — see /methods/residual-solvents-q3c/0.99%NOT TESTED
Endotoxinkinetic chromogenic LAL1.56EU/mg≤ 5.0PASS
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 calibration4.142.5 – 8.0PASS
Retention time (observed)RP-HPLC, 35 min gradient15.82min15.99 ± 0.30 (normalised)PASS
Peak asymmetry (10 % height)Ph. Eur. 2.2.461.100.80 – 1.50PASS
Plate count, main peakN = 5.54 (t/w½)²51,832≥ 20,000PASS
Resolution to nearest impurityvs free base (des-mesylate, −96 Da)0.16no 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.

01553310746606213 MK-677 (Ibutamoren mesylate)15.82 min · 97.67 % 15.216.25 same trace · ×50 vertical expansion, baseline-corrected · main peak off-scale reporting threshold 0.05 % area 0510152025303540 Retention time (min) Response (mAU)
Figure 1. RP-HPLC trace, 35 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 51,832, and skew follows the reported asymmetry factor of 1.10. 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 1.05 % impurity against a 97.67 % main peak is a line two pixels tall; the main peak runs off-scale there by design.
#PeakRTArea (µV·s)% areaΔ mass (Da)
1MK-677 (Ibutamoren mesylate) — main peak15.824,747,06597.67
2O-desmethyl metabolite analogue (−14 Da)15.2151,0331.05-14.016
3spiroindane regioisomer16.3325,7600.530.000
4free base (des-mesylate, −96 Da)15.8714,5810.30-96.011
5sulfonamide hydrolysis product (+18 Da)14.8211,6650.24+18.011
6residual DMF (process solvent)6.2510,2070.21-551.000
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 624.2181 Da, computed from C27H36N4O5S · CH4O3S. All ppm figures on this site are against monoisotopic values — see why that matters.

0255075100250325400475550625700 [M+1H]1+625.23[M+2H]2+313.12 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 624.2202 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 (%)
2+313.1163313.11740.001157.8
1+625.2254625.22750.0021100.0
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 Fischer3.95
Counter-ion (mesylate)ion chromatography14.85
Residual solvent + inorganic residueestimated0.99
Total peptide contentby difference80.21
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)97.8497.67divergence -0.14 pp vs batch median
Total impurities (% area)2.162.33
Largest single impurity (% area)1.321.05
Water (%)2.03.95
Counter-ion (%)3.114.85
Peptide content (%w/w)97.680.21
Endotoxin (EU/mg)1.001.56
Method stated on certificateYEScolumn, 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
Retail purchase → submitter (ambient, 32 d) → laboratory (hand-carried, 4 d) → assay.
Assay date
22 Feb 2026
Submitted to the index
05 Mar 2026
Laboratory
Nordanalyt Laboratories, Uppsala, Sweden
Method basis
35 min gradient · high-resolution MS
Verification status
VERIFIED
Section 6

Annotations 4

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.

iqr_watcher
One low result does not characterise a supplier and one high one does not either. The question is whether this lot sits in the left tail of a tight distribution or in the middle of a wide one, and the scorecard's IQR answers it.
isotope_cluster
The isotope pattern is consistent with the elemental composition of MK-677 (Ibutamoren mesylate). That is a second, independent check on identity and it agrees with the mass.
Where two compounds elute within a third of a minute, a mass at this accuracy is what separates them. Retention alone would not have.
fill_homogeneity
One retail vial is one draw from a fill. Two or three from the same lot would separate fill variation from lot quality, and that is the cheapest useful experiment in this whole field.
Section 7

Related records

Same batch — lot BCH-2601-G7291 n=7

ReportLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043697BCH-2601-G7291PeptideMeter2026-Q198.264.31Buyer-sourced1FAIL
AX-2026-043699BCH-2601-G7291PeptideMeter2026-Q198.093.9897.5Buyer-sourced1FAIL
AX-2026-043700BCH-2601-G7291Medutest2026-Q197.983.5989.1Buyer-sourced2FAIL
AX-2026-043701BCH-2601-G7291Janoshik2026-Q197.974.13101.5Buyer-sourced1FAIL
AX-2026-043702BCH-2601-G7291Medutest2026-Q198.413.7192.0Laboratory-retained1FAIL
AX-2026-043703BCH-2601-G7291Janoshik2026-Q197.974.1497.4Buyer-sourced1FAIL
Other recent MK-677 (Ibutamoren mesylate) records in the index.
ReportSupplierLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-041754FGPFGP-2604-K9878Janoshik2026-Q299.895.0693.8Buyer-sourced0FAIL
AX-2026-042619SWBSWB-2605-B6440Janoshik2026-Q299.303.05Buyer-sourced0FAIL
AX-2026-041756FGPFGP-2604-K9878Janoshik2026-Q299.624.4189.4Buyer-sourced1FAIL
AX-2026-041751FGPFGP-2604-K9878Janoshik2026-Q299.795.6988.7Buyer-sourced1FAIL
AX-2026-043676BCHBCH-2511-G7498Medutest2026-Q298.864.8199.6Buyer-sourced1FAIL
AX-2026-043678BCHBCH-2511-G7498Kestrel2026-Q298.743.73Buyer-sourced0FAIL
AX-2026-041753FGPFGP-2604-K9878Janoshik2026-Q299.935.7288.7Buyer-sourced1FAIL
AX-2026-043677BCHBCH-2511-G7498Janoshik2026-Q298.834.58Supplier-supplied0FAIL
Other recent BCH records in the index.
ReportCompoundLotLabQuarterPurity %Water %Recovery %ProvenanceFlagsResult
AX-2026-043691BPC-157BCH-2603-L7768Janoshik2026-Q398.665.12Supplier-supplied1MARGINAL
AX-2026-043693BPC-157BCH-2603-L7768PeptideMeter2026-Q397.825.2194.9Buyer-sourced0FAIL
AX-2026-043686BPC-157BCH-2603-L7768VendorInvestigate2026-Q397.645.27Buyer-sourced0FAIL
AX-2026-043695BPC-157BCH-2603-L7768Janoshik2026-Q397.615.42Buyer-sourced0FAIL
AX-2026-043726N-Acetyl Semax AmideBCH-2602-E8475Janoshik2026-Q397.899.67104.2Buyer-sourced0FAIL
AX-2026-043688BPC-157BCH-2603-L7768Janoshik2026-Q397.945.56Buyer-sourced0FAIL
AX-2026-043658BPC-157BCH-2603-G6644Janoshik2026-Q398.454.37101.8Supplier-supplied0PASS
AX-2026-043692BPC-157BCH-2603-L7768VendorInvestigate2026-Q397.605.61Buyer-sourced0FAIL