Every named impurity on this record has a mass defect consistent with its structural assignment. That is the check that distinguishes an assignment from a guess.
AX-2024-004687
MK-677 (Ibutamoren mesylate) · 250 mg declared · Hunan Aslsen Technology Co., Ltd. · lot HOMO-2401-J3421
FAILVERIFIED
- Report ID
- AX-2024-004687
- Compound
- MK-677 (Ibutamoren mesylate)
- Compound class
- Non-peptide adjuncts
- Supplier
- Homopeptide — Hunan Aslsen Technology Co., Ltd.
- Batch / lot
- HOMO-2401-J3421
- Declared label claim
- 250mg
- Laboratory
- PeptideMeter
- Assay date
- 07 Apr 2024
- Submitted
- 24 Apr 2024
- Quarter
- 2024-Q2
- Submitter
- c18_2p6
- 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.
| Parameter | Method | Result | Unit | Index spec | |
|---|---|---|---|---|---|
| Purity | RP-HPLC, 28 min gradient, 214 nm | 99.76 | % area | ≥ 98.5 | PASS |
| Total impurities | RP-HPLC, sum of reported peaks | 0.24 | % area | ≤ 1.5 | PASS |
| Largest single impurity | RP-HPLC — residual DMF (process solvent) | 0.14 | % area | ≤ 1.00 | PASS |
| Identity — theoretical monoisotopic mass | calculated from molecular formula | 624.2181 | Da | — | NOT TESTED |
| Identity — observed monoisotopic mass | LC-MS, high resolution (ESI-TOF/QTOF) | 624.2203 | Da | — | NOT TESTED |
| Mass accuracy | observed vs theoretical | +3.5 | ppm | ± 10 | PASS |
| Total peptide content | by difference from the gravimetric mass balance | 80.68 | %w/w | — | NOT TESTED |
| Target-compound content | total peptide content × purity | 80.49 | %w/w | — | NOT TESTED |
| Gross fill (as weighed) | five-place balance, under nitrogen | 280.95 | mg | 250 mg declared | NOT TESTED |
| Recovered target peptide | gross fill × target content | 226.137 | mg | 250 mg claim | NOT TESTED |
| Recovery against label claim | recovered ÷ claim | 90.5 | % | 90.0 – 110.0 | PASS |
| Water content | Karl Fischer, coulometric, duplicate | 3.83 | % | ≤ 10.0 | PASS |
| Counter-ion (mesylate) | anion-exchange ion chromatography | 15.17 | % | ≤ 12.0 | FAIL |
| Residual solvent + inorganic residue | estimated — see /methods/residual-solvents-q3c/ | 0.32 | % | — | NOT TESTED |
| Endotoxin | not ordered on this submission | not determined | — | ≤ 5.0 | NOT TESTED |
| Sterility | not ordered on this submission | not determined | — | no growth | NOT TESTED |
| Appearance | visual, diffuse light, black and white background | White lyophilised cake, intact | — | white to off-white intact cake | PASS |
| Reconstitution clarity | reconstituted per submitter procedure | Visible particulates, did not clear | — | clear, no visible particulates | FAIL |
| pH (reconstituted, 1 mg/mL) | potentiometric, two-point calibration | 5.33 | — | 2.5 – 8.0 | PASS |
| Retention time (observed) | RP-HPLC, 28 min gradient | 13.11 | min | 13.01 ± 0.30 (normalised) | PASS |
| Peak asymmetry (10 % height) | Ph. Eur. 2.2.46 | 1.26 | — | 0.80 – 1.50 | PASS |
| Plate count, main peak | N = 5.54 (t/w½)² | 75,844 | — | ≥ 20,000 | PASS |
| Resolution to nearest impurity | vs free base (des-mesylate, −96 Da) | 0.19 | — | 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.
| # | Peak | RT | Area (µV·s) | % area | Δ mass (Da) |
|---|---|---|---|---|---|
| 1 | MK-677 (Ibutamoren mesylate) — main peak | 13.11 | 4,848,645 | 99.76 | — |
| 2 | residual DMF (process solvent) | 5.46 | 6,804 | 0.14 | -551.000 |
| 3 | free base (des-mesylate, −96 Da) | 13.15 | 2,916 | 0.06 | -96.011 |
| 4 | sulfonamide hydrolysis product (+18 Da) | 12.31 | 1,944 | 0.04 | +18.011 |
| 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 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.
| Charge | Theoretical m/z | Observed m/z | Δ m/z | Rel. abundance (%) |
|---|---|---|---|---|
| 2+ | 313.1163 | 313.1174 | 0.0011 | 62.0 |
| 1+ | 625.2254 | 625.2276 | 0.0022 | 100.0 |
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.
| Component | Determination | %w/w of cake |
|---|---|---|
| Water | Karl Fischer | 3.83 |
| Counter-ion (mesylate) | ion chromatography | 15.17 |
| Residual solvent + inorganic residue | estimated | 0.32 |
| Total peptide content | by difference | 80.68 |
| 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) | 99.90 | 99.76 | divergence +0.05 pp vs batch median |
| Total impurities (% area) | 0.10 | 0.24 | |
| Largest single impurity (% area) | 0.03 | 0.14 | |
| Water (%) | 4.2 | 3.83 | |
| Counter-ion (%) | 7.0 | 15.17 | |
| Peptide content (%w/w) | 88.2 | 80.68 | |
| Endotoxin (EU/mg) | 0.19 | not determined | |
| Method stated on certificate | YES | — | 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
- Retail purchase → submitter (2–8 °C, 32 d) → laboratory (courier, ambient, 7 d) → assay.
- Assay date
- 07 Apr 2024
- Submitted to the index
- 24 Apr 2024
- Laboratory
- PeptideMeter, Tallinn, Estonia
- Method basis
- 28 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.
Where two laboratories tested the same retail lot, the paired difference is a clean estimate of inter-lab bias with no selection term in it at all. Those pairs are the backbone of the agreement analysis.
A retail vial is also a test of the label. Declared claim 250 mg against what the gravimetry recovers is a question only a purchased vial can answer honestly.
Retail purchases test the retail channel. Manufacturer-tier material bought at kilogram scale is a different product with different documentation, and this index sees very little of it.
Section 7
Related records
Same batch — lot HOMO-2401-J3421 n=6
| Report | Lot | Lab | Quarter | Purity % | Water % | Recovery % | Provenance | Flags | Result |
|---|---|---|---|---|---|---|---|---|---|
| AX-2024-004688 | HOMO-2401-J3421 | VendorInvestigate | 2024-Q2 | 99.27 | 4.46 | 95.1 | Buyer-sourced | 0 | FAIL |
| AX-2024-004689 | HOMO-2401-J3421 | PeptideMeter | 2024-Q2 | 99.93 | 4.28 | 105.9 | Buyer-sourced | 0 | FAIL |
| AX-2024-004690 | HOMO-2401-J3421 | Janoshik | 2024-Q2 | 99.77 | 4.40 | — | Buyer-sourced | 0 | FAIL |
| AX-2024-004691 | HOMO-2401-J3421 | PeptideMeter | 2024-Q2 | 99.93 | 4.56 | — | Buyer-sourced | 0 | FAIL |
| AX-2024-004692 | HOMO-2401-J3421 | Kestrel | 2024-Q2 | 99.93 | 4.73 | — | Buyer-sourced | 1 | FAIL |
| Report | Supplier | Lot | Lab | Quarter | Purity % | Water % | Recovery % | Provenance | Flags | Result |
|---|---|---|---|---|---|---|---|---|---|---|
| AX-2026-041633 | FGP | FGP-2604-K8509 | PeptideMeter | 2026-Q2 | 99.81 | 4.91 | 96.2 | Buyer-sourced | 0 | FAIL |
| AX-2026-041733 | TFS | TFS-{CAT}-1096 | PeptideMeter | 2026-Q2 | 99.07 | 3.93 | 95.1 | Laboratory-retained | 0 | FAIL |
| AX-2026-043468 | BCH | BCH-2511-G5204 | Medutest | 2026-Q2 | 98.85 | 4.30 | 96.5 | Buyer-sourced | 1 | FAIL |
| AX-2026-042647 | SWB | SWB-2605-B7365 | Nordanalyt | 2026-Q2 | 99.28 | 2.86 | 93.1 | Buyer-sourced | 0 | FAIL |
| AX-2026-041634 | FGP | FGP-2604-K8509 | PeptideMeter | 2026-Q2 | 99.86 | 5.17 | — | Buyer-sourced | 0 | FAIL |
| AX-2026-043469 | BCH | BCH-2511-G5204 | Medutest | 2026-Q2 | 98.51 | 4.86 | — | Buyer-sourced | 1 | FAIL |
| AX-2026-042648 | SWB | SWB-2605-B7365 | Janoshik | 2026-Q2 | 99.93 | 2.60 | 96.9 | Supplier-supplied | 0 | FAIL |
| AX-2026-041732 | TFS | TFS-{CAT}-1096 | Janoshik | 2026-Q2 | 99.48 | 3.16 | 106.4 | Buyer-sourced | 0 | FAIL |
| Report | Compound | Lot | Lab | Quarter | Purity % | Water % | Recovery % | Provenance | Flags | Result |
|---|---|---|---|---|---|---|---|---|---|---|
| AX-2026-042437 | Retatrutide | HOMO-2605-V4718 | Nordanalyt | 2026-Q3 | 98.68 | 3.67 | 102.8 | Buyer-sourced | 0 | PASS |
| AX-2026-042424 | Semaglutide | HOMO-2604-X3806 | PeptideMeter | 2026-Q3 | 98.85 | 4.87 | 92.0 | Buyer-sourced | 0 | PASS |
| AX-2026-042503 | IGF-1 LR3 | HOMO-2607-P5131 | Janoshik | 2026-Q3 | 99.36 | 5.99 | — | Buyer-sourced | 0 | PASS |
| AX-2026-042492 | SS-31 (Elamipretide) | HOMO-2604-D5484 | Medutest | 2026-Q3 | 99.93 | 2.40 | — | Buyer-sourced | 0 | PASS |
| AX-2026-042491 | SS-31 (Elamipretide) | HOMO-2604-D5484 | Kestrel | 2026-Q3 | 99.93 | 3.24 | — | Supplier-supplied | 0 | PASS |
| AX-2026-042473 | LL-37 | HOMO-2602-G5165 | Janoshik | 2026-Q3 | 99.01 | 5.00 | — | Buyer-sourced | 0 | PASS |
| AX-2026-042441 | Retatrutide | HOMO-2605-V4718 | Medutest | 2026-Q3 | 98.93 | 4.22 | — | Buyer-sourced | 0 | PASS |
| AX-2026-042474 | LL-37 | HOMO-2602-G5165 | Janoshik | 2026-Q3 | 99.18 | 5.44 | — | Buyer-sourced | 0 | PASS |