In detail

Withanolides are a family of steroidal lactones found in Withania somnifera. Commercial root extracts are typically standardized to 2.5% or 5% total withanolides by HPLC, with withaferin A often reported separately. The plant part matters: root-only material is a different label ingredient from root-plus-leaf material.

A withanolide percentage is only comparable when the method and plant part are stated. UV methods can produce different numbers from HPLC, and a high percentage does not by itself establish root sourcing. For premium positioning, ask for the plant part, the HPLC result, and a chromatogram.

Why it matters to a buyer

  • It is the marker most buyers print on an ashwagandha label.
  • Root versus root-plus-leaf is a labeling and cost issue, not a detail.
  • Method and marker definition affect comparability between suppliers.

What to ask a supplier

01

Is the material root-only, and how is that verified?

02

Which withanolides are included in the total, and by which method?

03

Can you provide a chromatogram and the withaferin A result?

Cite this page

Rainwood Botanical. "Withanolides." Botanical extract glossary, October 2026. https://ingredients.rainwoodbio.com/resources/glossary/withanolides/