Ashwagandha has been used as an adaptogen, diuretic, and sedative and is available in the United States as a dietary supplement. Trials supporting its clinical use are limited; however, many in vitro and animal experiments suggest effects on the immune and CNS systems, as well as in the pathogenesis of cancer and inflammatory conditions.
Dosing information is limited. W. somnifera root powder has generally been used at dosages of 450 mg to 2 g in combination with other preparations.
Contraindications have not been identified.
Limited clinical trials are available and case reports are lacking.
Acute toxicity of W. somnifera is modest; at reasonable doses, ashwagandha is nontoxic.
W. somnifera is an erect, greyish, slightly hairy evergreen shrub that grows to about 1.5 m in height and has fairly long tuberous roots. It is widely cultivated in India and throughout the Middle East and is found in eastern Africa. The small and greenish-yellow flowers can be single or in clusters. The fruit is smooth, round, and fleshy, with many seeds; it is orange-red when ripe and enclosed in a membranous covering. 1
The root of W. somnifera is used to make the Ayurvedic tonic ashwagandha , which has been translated to “smells like a horse.” 2 Ashwagandha has been used as an adaptogen, diuretic, and sedative and is available in the United States as a dietary supplement. Other parts of the plant (eg, seeds, leaves) have been used as a pain reliever, to kill lice, and in making soap. The fresh berries have been used as an emetic. 2 , 3
The principal bioactive compounds of W. somnifera are withanolides, which are triterpene lactones. More than 40 withanolides and approximately 12 alkaloids and several sitoindosides have been isolated and identified from W. somnifera . The withanolides are structurally related to the ginsenosides of Panax ginseng, hence the common name “Indian ginseng.” 3 , 4 Chemical constituents for the roots, fruits, seeds, and stem include withanone; withaferin A; withanolides A, D, an G; and sitoindosides IX, X, VII, and VIII. High performance liquid chromatography techniques to quantify constituents have also been established