Why we test for thallium

Every credible supplement brand tests for lead, arsenic, mercury and cadmium. Those four have legal limits, so testing for them is a compliance activity rather than a virtue.

Thallium has no such limit in a food supplement, which means nobody has to look for it, which means almost nobody does. It is also unusually relevant to this particular ingredient: published analysis has found thallium in finished shilajit supplements at higher concentrations than in the raw material they were made from — implying it arrived somewhere in processing rather than from the mountain.

So we test for it, and we publish the number alongside the other four, together with the limit of quantification. That last part matters more than people realise. “Not detected” is not a result; it is the absence of one. Without knowing the smallest amount the instrument could have found, it tells you nothing at all.

None of this is expensive. It is simply not required, and in a category where a great many things are not required, what a brand does anyway is most of what you have to go on.