Ashwagandha Root vs Leaf Extract & the Withaferin A Tell

Same Plant, Different Parts

Withania somnifera yields several distinct ingredients depending on the part used. The traditional Ayurvedic material is the root. Leaf and whole-plant (aerial + root) extracts also exist and are legitimate ingredients in their own right — but they are not interchangeable with a root extract, because their withanolide composition differs.

Root vs Leaf at a Glance

Withaferin A: The Analytical Tell

The most reliable way to distinguish the parts is withaferin A. This specific withanolide concentrates in the leaves, so a high withaferin A share in a powder sold as "root extract" is a strong signal that leaf or whole-plant material is present. For a genuine root grade, buyers should look for a low or limited withaferin A — and can specify a withaferin A ceiling on the purchase order. Only HPLC resolves withaferin A individually; a gravimetric total will not, which is one reason the assay method matters.

The Colour & Odour Test

Genuine ashwagandha root extract is a light to dark brown fine powder with a characteristic, slightly horsey odour. A pronounced green or olive tint often indicates leaf or whole-plant content. As with any botanical, colour is a fast first screen rather than proof — pair it with the CoA and, where it matters, an HPLC withaferin A figure.

The Root-and-Leaf Argument, and Why We Still Specify Root

Several branded ashwagandha ingredients are now made from root and leaf, and their makers publish trials and patents to support that choice. It is a legitimate product class, and a buyer who wants it should buy it knowingly. What it is not is the same material as a root extract, and the difference is measurable rather than rhetorical.

The pharmacopoeial position is root. The United States Pharmacopeia, the British Pharmacopoeia and the Ayurvedic Pharmacopoeia of India define ashwagandha as the dried root of Withania somnifera. A 2025 study from the National Center for Natural Products Research applied both the BP and USP HPLC methods to commercial supplements and found that only two of twenty-five products could be confirmed as root-derived; the rest contained varying, often undisclosed, proportions of aerial parts, and the leaf-derived withanolide sulfate that co-elutes in those samples was the reason many products failed the monographs. The chemistry is different. A validated chromatographic comparison of the same plants grown under the same conditions found the highest withaferin A in leaves and the highest withanolide A and B in roots, which is exactly the profile difference this page describes. The safety literature is watching the plant part. Reviews of herb-induced liver injury in Indian systems of medicine now list ashwagandha among the herbs with reported cases, and part-of-plant and adulteration are among the variables those reviews ask suppliers to control.

None of this makes a root-and-leaf extract a bad product. It makes it a different product, one that should be specified, labelled and priced as such, with its own withaferin A figure on the certificate. SV Botanica supplies root-only material because that is what the monographs describe, what the traditional dose history refers to, and what a buyer can verify with a withaferin A number. The references at the end of this article carry the studies cited here.

Authenticating Before You Buy

• Specify the part. "Withania somnifera root extract" on the spec and PO, not just "ashwagandha extract".
• Request identity testing. TLC or HPLC identification confirming Withania somnifera.
• Ask for withaferin A. Low/limited for a root grade; request it by HPLC if it is critical.
• Screen the colour. Brown, not green; characteristic odour.
• Get a batch CoA. Part used, assay method, contaminant panel and traceability.

SV Botanica supplies a root-only 5% withanolide grade. For the full purchasing checklist, see the buyer's guide.