When buyers ask about lab testing they usually mean potency – is the milligram content accurate? That is only half of what a certificate of analysis is for. The other half is purity, and heavy metals are the clearest example of why.
Why plants contain metals at all
Plants take up minerals from soil through their roots. That process is not selective: alongside the nutrients a plant needs, it can also accumulate metals that are present in the soil, including lead, cadmium, arsenic and mercury.
This is true of all botanical products – tea, rice, cocoa, herbal supplements, and kratom leaf. It is not a sign of a bad farm. It is a natural phenomenon that needs to be measured.
What the panel tests for
| Metal | Why it is tested |
|---|---|
| Lead | Accumulates in soil, particularly in areas with industrial history |
| Cadmium | Readily taken up by plants; a common finding in botanical products |
| Arsenic | Naturally occurring in some soils and groundwater |
| Mercury | Less common in plants, but included in standard panels |
Why the extraction process matters
Concentrating alkaloids also concentrates whatever else is in the input material. If the leaf carries elevated metals, an extract made from it can carry them at higher concentration. This is precisely why testing the finished extract – not only the raw leaf – is the meaningful check.
What a good report looks like
- Each metal reported individually, with a numeric result
- Units stated – typically parts per million or micrograms per gram
- Reporting limits included
- A clear pass/fail or “below limit” determination
- Matched to a specific batch number
What a poor report looks like: a single line saying “heavy metals: pass” with no numbers. That is not a measurement, it is an assertion.
Why this matters even though you take milligrams
The amount of product used per serving is small, which is genuinely reassuring. But exposure accumulates over time, and the point of testing is to eliminate the question rather than to estimate it away. If a batch carries elevated metals, the correct action is to reject it – not to calculate whether the exposure is probably acceptable.
How to check your vendor
- Ask for the batch-matched COA – see how to request one.
- Check that the heavy metals panel is present, not just potency.
- Check that results are numeric and below stated limits.
- Check that the laboratory is independent and verifiable.
- If a vendor’s report has no numbers, treat the testing claim as unverified.
Our position
Every batch we sell is screened for heavy metals as part of a full purity panel. We will not sell a batch that fails. Reports are available on request from the Lab Results page.
Related reading
See our lab results
Independently tested, batch by batch, with purity panels available on request.



