VendorInvestigate
The only contributor that routinely purchases material anonymously rather than accepting submitted samples. 601 reports in the index — 8.9 % of the total.
Identification and method basis
- Laboratory
- VendorInvestigate
- Short code in this index
- VendorInvestigate
- Location
- Riga, Latvia
- Founded
- 2022
- Reports contributed
- 601
- Share of index
- 8.9%
- Purity gradient
- 32min
- Mass resolution
- High resolution (ESI-TOF / QTOF)
- Stated turnaround
- 5–10 business days
- Measured offset vs reference
- -0.493 pp
- Within-lab repeatability
- 0.30pp
VendorInvestigate's methodological contribution to the index is procedural rather than instrumental: it purchases material anonymously, through unattributed channels, and controls the chain of custody from checkout to injection. Ninety-four per cent of VendorInvestigate reports in the index are buyer-sourced, against an index average of 85 %, and none are supplier-supplied.
That matters because the index can measure the difference. Across all paired comparisons where the same lot was assayed from both a supplier-supplied sample and an independently purchased vial, the supplier-supplied result reads a mean 0.31 pp higher (n=88, 95 % CI 0.19 to 0.43). VendorInvestigate's record set is the cleanest available subset for anyone who wants to exclude that effect entirely, and several of the index's supplier scorecards use it as a sensitivity check.
VendorInvestigate also performs a gravimetric fill check — weighing the vial before and after reconstitution — which is the only direct measurement of label-claim compliance in the index. It reveals that under-fill is more common than over-fill by roughly three to one.
Measured bias is −0.11 pp on 91 paired comparisons. The 32-minute gradient is the longest in use here and slightly better resolving than the reference, which is the likely source of the small negative offset: a longer gradient separates more, and separating more lowers the apparent main-peak area.
Methods offered
What a laboratory can measure decides what a record can establish. A submission that orders only purity produces a record that names nothing.
- RP-HPLC purity (%area, 214 nm)
- LC-MS identity (ESI-QTOF)
- blind-purchase chain of custody
- counter-ion by ion chromatography
- label-claim verification by gravimetric fill check
What this laboratory has measured
| Compound class | Reports | Median purity | Method suitability |
|---|---|---|---|
| Incretin analogues and co-agonists | 227 | 98.11 | ADEQUATE |
| Tissue-repair and immunomodulatory peptides | 113 | 98.82 | ADEQUATE |
| Growth-hormone axis peptides | 90 | 98.47 | ADEQUATE |
| Neuroactive and cognitive peptides | 43 | 98.85 | ADEQUATE |
| Melanocortin-receptor peptides | 40 | 98.88 | ADEQUATE |
| Non-peptide adjuncts | 29 | 98.60 | ADEQUATE |
| Metabolic and mitochondrial peptides | 26 | 98.39 | ADEQUATE |
| Short bioregulator peptides | 22 | 98.53 | ADEQUATE |
| Hypothalamic and posterior-pituitary hormones | 11 | 98.62 | ADEQUATE |
| Most-tested compounds here | Reports | Median purity |
|---|---|---|
| Semaglutide | 102 | 98.37 |
| BPC-157 | 51 | 98.79 |
| Retatrutide | 49 | 97.89 |
| Tirzepatide | 49 | 97.80 |
| TB-500 | 34 | 99.00 |
| Melanotan II | 21 | 98.73 |
| Ipamorelin | 18 | 99.13 |
| Semax | 17 | 98.85 |
| CJC-1295 (no DAC) | 15 | 98.39 |
| MK-677 (Ibutamoren mesylate) | 15 | 98.26 |
| GHRP-6 | 12 | 99.22 |
| KPV | 11 | 98.70 |
| Selank | 11 | 98.65 |
| PT-141 (Bremelanotide) | 10 | 99.03 |
| ARA-290 | 10 | 98.75 |
| Liraglutide | 9 | 98.69 |
Agreement with the other laboratories
Each row is a paired analysis: batches where this laboratory and another one both assayed the same physical lot. A difference on a matched pair is bias plus noise, and it is the only clean way to compare laboratories.
| Against | Paired lots | Mean difference (pp) | 95 % limits of agreement | Within 0.5 pp |
|---|---|---|---|---|
| Janoshik | 380 | -0.493 | -1.27 to 0.29 | 51% |
| PeptideMeter | 272 | -0.451 | -1.32 to 0.42 | 54% |
| Medutest | 249 | -0.559 | -1.45 to 0.33 | 44% |
| Nordanalyt | 174 | -0.498 | -1.26 to 0.27 | 51% |
| Kestrel | 143 | -0.913 | -1.94 to 0.11 | 21% |
Positive means VendorInvestigate read higher. The full paired analysis, with its assumptions →
Provenance of what this laboratory receives
A laboratory that mostly receives supplier-supplied samples produces a record set with a known upward pressure on it, however good its analysis is. This is a property of the submission channel and not of the laboratory.
| Provenance | Reports | Share | Evidentiary weight | |
|---|---|---|---|---|
| Buyer-sourced | 568 | 94.5% | Strongest available evidence in this index. | |
| Supplier-supplied | 0 | 0.0% | Weaker evidence. Read with the caveat below. | |
| Laboratory-retained | 33 | 5.5% | Provenance documented, selection uncontrolled. |