GSP-2501-R2783
MK-677 (Ibutamoren mesylate) · 1000 mg declared · GenScript Biotech Corporation · manufactured 18 Jan 2025
- Lot code
- GSP-2501-R2783
- Supplier
- GSP — GenScript Biotech Corporation
- Compound
- MK-677 (Ibutamoren mesylate)
- Compound class
- Non-peptide adjuncts
- Declared label claim
- 1000mg
- Manufacture date
- 18 Jan 2025
- Index quarter
- 2025-Q1
- Independent assays
- 10
- Laboratories involved
- Medutest, Janoshik, VendorInvestigate, PeptideMeter, Nordanalyt
- Provenance mix
- Buyer-sourced ×7 · Supplier-supplied ×1 · Laboratory-retained ×2
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.
Member reports 10
Every report the index holds on this lot. Each is a page carrying its own chromatogram, mass spectrum, mass balance, provenance and caveats.
| Report | Lot | Lab | Quarter | Purity % | Water % | Recovery % | Provenance | Flags | Result |
|---|---|---|---|---|---|---|---|---|---|
| AX-2025-019057 | GSP-2501-R2783 | Medutest | 2025-Q1 | 99.45 | 6.07 | 96.3 | Buyer-sourced | 0 | FAIL |
| AX-2025-019058 | GSP-2501-R2783 | Janoshik | 2025-Q1 | 99.62 | 6.26 | 105.6 | Laboratory-retained | 0 | FAIL |
| AX-2025-019059 | GSP-2501-R2783 | VendorInvestigate | 2025-Q1 | 98.90 | 5.43 | 103.0 | Buyer-sourced | 0 | FAIL |
| AX-2025-019060 | GSP-2501-R2783 | PeptideMeter | 2025-Q1 | 99.43 | 5.64 | 90.3 | Buyer-sourced | 0 | FAIL |
| AX-2025-019061 | GSP-2501-R2783 | Janoshik | 2025-Q1 | 99.49 | 5.70 | — | Buyer-sourced | 0 | FAIL |
| AX-2025-019062 | GSP-2501-R2783 | Medutest | 2025-Q1 | 99.85 | 5.91 | — | Buyer-sourced | 0 | FAIL |
| AX-2025-019063 | GSP-2501-R2783 | Medutest | 2025-Q1 | 99.93 | 4.98 | — | Supplier-supplied | 1 | FAIL |
| AX-2025-019064 | GSP-2501-R2783 | PeptideMeter | 2025-Q1 | 99.41 | 5.84 | — | Buyer-sourced | 0 | FAIL |
| AX-2025-019065 | GSP-2501-R2783 | Nordanalyt | 2025-Q1 | 99.26 | 6.13 | — | Laboratory-retained | 0 | FAIL |
| AX-2025-019066 | GSP-2501-R2783 | Medutest | 2025-Q1 | 99.62 | 6.02 | 91.2 | Buyer-sourced | 0 | FAIL |
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.
| Laboratory | Reports | Purity results (% area) | Median | Gradient | Published bias (pp) | Bias-adjusted |
|---|---|---|---|---|---|---|
| Medutest | 4 | 99.45, 99.85, 99.93, 99.62 | 99.73 | 25min | +0.08 | 99.66 |
| Janoshik | 2 | 99.62, 99.49 | 99.56 | 30min | +0.00 | 99.56 |
| VendorInvestigate | 1 | 98.90 | 98.90 | 32min | -0.11 | 99.01 |
| PeptideMeter | 2 | 99.43, 99.41 | 99.42 | 28min | -0.05 | 99.47 |
| Nordanalyt | 1 | 99.26 | 99.26 | 35min | +0.02 | 99.24 |
This lot contributes 10 paired comparisons to the inter-lab analysis.
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.
| Figure | Supplier COA | This report | Index note |
|---|---|---|---|
| Purity (% area) | 100.0 | 99.45 | divergence +0.53 pp vs batch median |
| Total impurities (% area) | not stated | 0.55 | |
| Largest single impurity (% area) | not stated | 0.34 | |
| Water (%) | 4.6 | 6.07 | |
| Counter-ion (%) | 3.3 | 15.64 | |
| Peptide content (%w/w) | 91.5 | 77.88 | |
| Endotoxin (EU/mg) | 0.87 | 1.57 | |
| Method stated on certificate | YES | — | column, gradient and wavelength given |
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 impurity | Reported in | Median % area | Range |
|---|---|---|---|
| spiroindane regioisomer | 10 / 10 | 0.17 | 0.03–0.50 |
| O-desmethyl metabolite analogue (−14 Da) | 9 / 10 | 0.04 | 0.02–0.25 |
| residual DMF (process solvent) | 9 / 10 | 0.07 | 0.05–0.11 |
| free base (des-mesylate, −96 Da) | 9 / 10 | 0.18 | 0.04–0.28 |
| sulfonamide hydrolysis product (+18 Da) | 2 / 10 | 0.04 | 0.03–0.05 |