Botanical identity testing confirms that a herb is the plant species, and the plant part, that it claims to be. It uses methods such as visual examination, microscopy, chromatographic fingerprints and sometimes DNA testing.
It matters because cut and powdered herbs are easy to substitute or dilute. For dietary supplements in the US, identity testing of ingredients is a regulatory requirement, and many buyers elsewhere expect it too.
Why identity goes wrong
- Similar species: related plants look alike and are sold under the same common name.
- Wrong plant part: leaf or stem in a root product, or stem in a leaf product.
- Deliberate adulteration: cheaper plants or fillers added to increase weight.
- Mix-ups at collection: wild collectors may gather similar plants together.
- Cross contamination: mills that process many herbs on the same line.
The main methods
No single method suits every herb. Powders and extracts often need more than one. Pharmacopoeia monographs usually name the identity tests for each herb. Our guide to HPTLC explains the most common fingerprint method.
- Macroscopic examination: shape, colour, smell and texture of whole or cut material, compared with a reference.
- Microscopy: cell structures, hairs, crystals and starch grains that are typical of a species and part.
- HPTLC: a chromatographic fingerprint compared side by side with authenticated reference material.
- HPLC: measures marker compounds and their pattern.
- DNA testing: useful for whole and cut herbs, less reliable for heavily processed material and extracts.
Who requires it
In the US, the FDA's good manufacturing practice rule for dietary supplements requires manufacturers to verify the identity of each dietary ingredient. Medicines in most markets must meet pharmacopoeia identity tests. Food and tea brands are not always legally bound to the same level, but retailers and their own quality systems often ask for it. See rules for selling botanicals as supplements in the US.
How to build it into your order
- State the botanical name, including the author name where your standard uses it, and the plant part.
- Name the identity method and the reference material to be used.
- Ask for identity results on every lot, not one certificate for the year.
- Keep retained samples so tests can be repeated.
- Use a lab with experience of the herb, not just a general food lab.
What identity testing costs you, and saves
Identity tests add time and cost to each lot, so some buyers skip them on familiar herbs. That is when problems slip through. A failed identity test before shipment costs far less than a recall, a lost retail listing or a regulator's warning after the goods are sold.
If you buy many herbs, agree a testing plan with your lab that covers identity on every lot and fuller safety tests at a set frequency.
How Creston & Co helps
We draw samples from the lot itself and send them to NABL-accredited labs that run the identity method you name, then share the original reports. Discuss your herbs in a free sourcing review.