Ashwagandha is the most traded Ayurvedic root in the world, and a commodity that busy is worth cheapening. The adulteration is rarely dramatic. It is a leaf fraction here, a carrier there, an assay method chosen for the number it gives. Each has a test that catches it, and a specification clause that makes the test binding.
1. Leaf in the root
Leaf is cheaper, more abundant and richer in withaferin A, a cytotoxic withanolide that many buyers cap because of its safety profile. A leaf fraction lifts the total withanolide number while lowering the cost of goods, so the incentive is obvious. The tell is the withanolide profile: root extracts carry withanolide A and the withanosides with withaferin A low; a high withaferin A share is leaf material, whatever the label says. Specify root only, ask for withaferin A as a number, and set a maximum. The root versus leaf guide covers the pharmacology behind the distinction.
2. Carrier dilution
Maltodextrin, silica and rice flour are legitimate processing aids at declared levels. Undeclared, they are dilution. The signals are a lighter colour, a milder taste, an unusually high water solubility for a hydroalcoholic extract, and a herb-to-extract ratio that does not add up. Ask the supplier to declare carriers and their percentage on the specification, and to state the herb-to-extract ratio; a 5% extract from root that assays around 0.3 to 0.5% withanolides cannot plausibly be a 4:1.
3. The assay that flatters
Gravimetric “total withanolides” weighs a solvent fraction, so anything that co-extracts into that fraction counts. It is a legitimate trade method and reads higher than HPLC on honest material; the abuse is presenting a gravimetric figure against a buyer’s HPLC specification, or not stating the method at all. Write the method into the specification and require it on the COA. Our note on gravimetric versus HPLC shows how far apart the numbers can sit on the same lot.
4. Species substitution
Less common in extract than in crude root, but it happens where root is bought in bulk from aggregators: Withania coagulans and unrelated roots have been reported as admixtures in market samples. TLC or HPTLC against a W. somnifera reference standard is the routine control; DNA-based identification is available for disputes but not needed lot by lot.
5. Spiking
Isolated withanolides or a high-potency leaf fraction added to a weak root extract to meet a number. The profile again gives it away: a spiked material shows a distorted ratio between glycosides and aglycones, or a single peak out of proportion to the rest. An HPLC report with the individual withanolides listed, not just a total, is the defence.
The controls, in one table
| Failure mode | Test that catches it | Specification clause |
|---|---|---|
| Leaf substitution | Withaferin A by HPLC; profile review | Root only; withaferin A NMT (agreed value) |
| Carrier dilution | Solubility, ash, taste; declared carriers | Carriers and % declared; herb-to-extract ratio stated |
| Assay inflation | HPLC against reference standards | Assay method named; HPLC report per lot |
| Species substitution | TLC / HPTLC vs reference | Identity by TLC to comply with reference material |
| Spiking | Individual withanolide breakdown | Glycoside and aglycone split reported |
What a clean supply looks like
Root sourced from known cultivation belts, extracted in a facility you can name a certificate for, assayed by a method written on the COA, and tested by a third party when you ask. That is the whole of it. SV Botanica’s ashwagandha is root only, the 2.5% export grade is assayed by HPLC with its COA published, and the 5% standard grade carries an HPLC profile per lot on request.
Root-only Ashwagandha Extract, profile-verified
Withaferin A reported on request, HPLC profile per lot, third-party testing available.