From the Manufacturer:
Popularly known as “Indian Ginseng” because of its widespread use as an adaptogen, Ashwagandha comes from the roots and leaves of Withania somnifera. It is concentrated and standardized for 4.5 mg withanolides per tablet, the active constituents of the plant. By standardizing the withanolide content in the product, researchers have been able to substantiate the traditional applications for Ashwagandha. This premium product, from the authentic Ayurvedic source, guarantees a consistent dosage in a fast-acting, assimilable form.