To be exact about it, the single strongest value proposition of Janoshik is that they publish all results in a database indexed by vendor and compound, which lets you compare your result to hundreds of other users.
The cost of testing is by sample submitted, not by parameter measured, so a single Janoshik result gives you purity, content and identity for less than most suppliers charge for purity alone.
It helps to be literal here: comparison across time on the same vendor's material — three lots of vendor X spread over six months — shows whether quality is trending or stable.
The database has been publicly available for long enough that systematic biases in their reporting would be apparent and would have been flagged by users.
The practical summary: submit your first lot to Janoshik and check the database for that vendor.
edited 28 Jul 2026 by Dr_Tomas_Kral — tightened the wording; no substantive change