Ashwagandha has a long history of use in traditional Indian medicine (Ayurveda). While a large body of clinical research is lacking, investigations for the use of Ashwagandha continue in immune, anxiety, stress, neurodegenerative disorders such as Parkinson’s and Alzheimer’s disorders, inflammatory conditions, and others.
History of Use
Ashwagandha (Withania somnifera) has been a popular herb in Ayurvedic herbal medicine for hundreds of years, where it is considered a general tonic. It has earned the title of the “Indian ginseng” in the west and has many of the same properties as Panax ginseng. Ashwagandha has been used as a general adaptogen, sedative and sleep aid, diuretic, and for pain. Ashwagandha has been researched as an ergogenic, libido, brain health aid.
The bioactive compounds in Ashwagandha under investigation are called withanolides (chemically classified as triterpene lactones). The withanolides are structurally similar to ginsenosides (found in Panax ginseng). Ashwagandha is high in iron.
Most research has used between 450 to 2,000 milligrams of Ashwagandha.
Studies, in animals and humans, have suggested that Ashwagandha may possess antioxidant, anti-inflammatory, stress reducing, and immunomodulatory effects. Some preliminary studies suggest that Ashwagandha may have some effects on the central nervous system and fertility, although a mechanism of action has yet to be elucidated.
Central Nervous System: A few small studies on the effects of Ashwagandha and brain health have been undertaken. To date, no study constitutes a strong recommendation for the use of Ashwagandha in brain health, but the studies appear to support some of the traditional uses of the herb.
- A preliminary double blind, placebo-controlled, randomized study of sixty patients with bipolar disorder were supplemented with 500 milligrams of Ashwagandha a day for eight weeks. At the end to the treatment period, those patients receiving Ashwagandha scored significantly better on three cognitive tasks (backward digit span, Flanker neutral response time and social cognition response) suggesting a role for Ashwagandha in maintaining cognitive function.
- The action of Ashwagandha (20 and 50 milligram/kg) were compared in rats to those elicited by lorazepam (0.5 mg/kg) and imipramine (10 mg/kg). Ashwagandha had a comparable anxiolytic effect to lorazepam in elevated plus-maze, social interaction, and feeding latency tests. Ashwagandha also had similar effect to forced swim, learned helplessness tests.
- Animal studies have shown cholinesterase inhibitory properties suggesting Ashwagandha as a potential Alzheimer’s adjuvant therapy.
Fertility: Two clinical studies in humans support the notion that Ashwagandha may improve sperm quality (but not sperm count).
- 180 infertile men were supplemented with five grams a day of Ashwagandha for three months in a non-placebo controlled trail. The men showed improved the quality of semen following treatment.
- Supplementation with Ashwagandha in 75 men undergoing fertility screening reduced oxidative stress and increased levels of testosterone, luteinizing hormone, folic stimulating hormone and prolactin (indicators of semen quality).
Toxicity studies suggest that Ashwagandha appears to be safe with very little side effects or adverse reports.
- Pregnancy: Avoid use, abortifacient properties have been suggested for Ashwagandha.
 Chengappa KN, Bowie CR, Schlicht PJ, Fleet D, Brar JS, Jindal R. Randomized placebo-controlled adjunctive study of an extract of withania somnifera for cognitive dysfunction in bipolar disorder. J Clin Psychiatry. 2013 Nov;74(11):1076-83. PMID: 24330893.
 Bhattacharya SK, Bhattacharya A, Sairam K, Ghosal S. Anxiolytic-antidepressant activity of Withania somnifera glycowithanolides: an experimental study. Phytomedicine. 2000 Dec;7(6):463-9. PMID: 11194174.
 Choudhary MI, Nawaz SA, ul-Haq Z,et al. Withanolides, a new class of natural cholinesterase inhibitors with calcium antagonistic properties. Biochem Biophys Res Commun. 2005 Aug 19;334(1):276-87. PMID: 16108094.
 Gupta A, Mahdi AA, Shukla KK, et al. Efficacy of Withania somnifera on seminal plasma metabolites of infertile males: a proton NMR study at 800 MHz. J Ethnopharmacol. 2013 Aug 26;149(1):208-14. PMID: 23796876.
 Ahmad MK, Mahdi AA, Shukla KK, et al. Withania somnifera improves semen quality by regulating reproductive hormone levels and oxidative stress in seminal plasma of infertile males. Fertil Steril. 2010 Aug;94(3):989-96 PMID: 19501822.
 Sharada AC, Solmon FE, Devi PU. Toxicity of Withania somnifera root extract in rats and mice. Int J Pharmacognosy . 1993;31(3):205-212.
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