VendorInvestigate
The only contributor that routinely purchases material anonymously rather than accepting submitted samples. 593 reports in the index — 9.0 % of the total.
Identification and method basis
- Laboratory
- VendorInvestigate
- Short code in this index
- VendorInvestigate
- Location
- Riga, Latvia
- Founded
- 2022
- Reports contributed
- 593
- Share of index
- 9.0%
- Purity gradient
- 32min
- Mass resolution
- High resolution (ESI-TOF / QTOF)
- Stated turnaround
- 5–10 business days
- Measured offset vs reference
- -0.142 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 | 210 | 98.50 | ADEQUATE |
| Growth-hormone axis peptides | 101 | 98.95 | ADEQUATE |
| Tissue-repair and immunomodulatory peptides | 97 | 99.10 | ADEQUATE |
| Metabolic and mitochondrial peptides | 41 | 98.70 | ADEQUATE |
| Neuroactive and cognitive peptides | 41 | 99.11 | ADEQUATE |
| Non-peptide adjuncts | 34 | 98.95 | ADEQUATE |
| Melanocortin-receptor peptides | 33 | 99.29 | ADEQUATE |
| Hypothalamic and posterior-pituitary hormones | 18 | 99.25 | ADEQUATE |
| Short bioregulator peptides | 18 | 99.37 | ADEQUATE |
| Most-tested compounds here | Reports | Median purity |
|---|---|---|
| Semaglutide | 78 | 98.71 |
| Tirzepatide | 60 | 98.41 |
| BPC-157 | 47 | 98.92 |
| Retatrutide | 37 | 98.34 |
| CJC-1295 (no DAC) | 28 | 98.88 |
| TB-500 | 24 | 99.42 |
| Semax | 21 | 99.09 |
| GHRP-6 | 18 | 99.59 |
| Ipamorelin | 17 | 99.22 |
| MOTS-c | 13 | 98.58 |
| AOD-9604 | 12 | 99.02 |
| GHRP-2 | 11 | 98.80 |
| PT-141 (Bremelanotide) | 11 | 99.16 |
| Melanotan II | 11 | 98.99 |
| SS-31 (Elamipretide) | 9 | 98.63 |
| Epitalon | 9 | 99.48 |
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 | 382 | -0.142 | -0.81 to 0.52 | 84% |
| PeptideMeter | 275 | -0.105 | -0.84 to 0.63 | 82% |
| Medutest | 258 | -0.212 | -1.02 to 0.59 | 73% |
| Nordanalyt | 179 | -0.134 | -0.91 to 0.64 | 82% |
| Kestrel | 143 | -0.546 | -1.58 to 0.49 | 48% |
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 | 557 | 93.9% | Strongest available evidence in this index. | |
| Supplier-supplied | 0 | 0.0% | Weaker evidence. Read with the caveat below. | |
| Laboratory-retained | 36 | 6.1% | Provenance documented, selection uncontrolled. |