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What is it?


Withania somnifera (WS) is also commonly known as ashwagandha, “Indian Winter cherry” or “Indian Ginseng”. Its root, leaves, and seeds have been historically used as a tonic to assist with stress, neuroprotection, arthritis, pain, and inflammation. It is one of the most highly regarded ayurvedic medicines. (20) Withania somnifera extract contains numerous phytochemicals, such as alkaloids, flavonoids, steroidal lactones, saponins, neurotransmitters, essential and nonessential fatty acids, ergostane, and gamma amino butyric acid, which contribute to its many therapeutic effects. (3)

Not be confused with: Withania coagulans 

Main uses

Anxiety and stress
Cognition in neurological disorders
Joint pain and muscular performance


Bioavailability and safety
Non-proprietary standardized extracts
Withanolides absorbed rapidly, withaferin A had 1.5x higher bioavailability than withanolide A in mice (17)
High dose of 2000mg/kg of body weight of a standardized extract containing <3% of Withaferin A did not produce adverse effects or toxicity in rats (16)
KSM-66® (root extract containing a 5% concentration of withanolides)
No data on bioavailability currently available
Has been shown to be safe for 12 weeks (1)
Sensoril® (root and leaf extract containing a minimum of 8% concentration of withanolides) (5)
No data on bioavailability currently available
Has been shown to be safe for 12 weeks (18)(23)
Shoden® (root and leaf extract standardized to 35% withanolide glycosides) (14)
No data on bioavailability currently available
Has been shown to be safe for 8 weeks (14)

Dosing & administration

Adverse effects

Ashwagandha is generally reported to be safe, with only minor adverse effects of gastrointestinal distress, diarrhea, nausea, and vomiting associated with large doses. Rare cases of hepatotoxicity have been reported. (15)



  • Withaferin-A and withanolide A have been shown to be rapidly absorbed in mice. (10)
  • Oral bioavailability of witherfarin A has shown to be ~32% in rats but can easily pass through epithelial cells as shown in vitro. (9)


  • From highest to lowest concentrations, withaferin A has been shown to have tissue distribution in the stomach, heart, lung, kidney, small intestine, and spleen in rats. (21)


  • Intestinal and liver first-pass metabolism may contribute to low bioavailability of witherfarin A as shown in rats and in vitro. (9)


  • No data currently available
  1. Ambiye, V. R., Langade, D., Dongre, S., Aptikar, P., Kulkarni, M., & Dongre, A. (2013). Clinical evaluation of the spermatogenic activity of the root extract of Ashwagandha (Withania somnifera) in oligospermic males: A pilot study. Evidence-Based Complementary and Alternative Medicine, 2013, 1-6. ()
  2. Auddy, B., Hazra, J., Mitra, A., Abedon, B., & Ghosal, S. (2008). A standardized Withania somnifera extract significantly reduces stress-related parameters in chronically stressed humans: A double-blind, randomized, placebo-controlled study. Journal of American Nutraceutical Association, 11(1), 51-57. ()
  3. Azgomi, R. N., Zomorrodi, A., Nazemyieh, H., Fazljou, S. M., Bazargani, H. S., Nejatbakhsh, F., . . . Asrbadr, Y. A. (2018). Effects of Withania somnifera on reproductive system: A systematic review of the available evidence. BioMed Research International,2018, 1-17. ()
  4. Chandrasekhar, K., Kapoor, J., & Anishetty, S. (2012). A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of Ashwagandha root in reducing stress and anxiety in adults. Indian Journal of Psychological Medicine, 34(3), 255-262. ()
  5. Chengappa, K. N., Bowie, C. R., Schlicht, P. J., Fleet, D., Brar, J. S., & Jindal, R. (2013). Randomized placebo-controlled adjunctive study of an extract of Withania somnifera for cognitive dysfunction in bipolar disorder. The Journal of Clinical Psychiatry, 74(11), 1076-1083. ()
  6. Chengappa, K. N., Brar, J. S., Gannon, J. M., & Schlicht, P. J. (2018). Adjunctive use of a standardized extract of Withania somnifera (Ashwagandha) to treat symptom exacerbation in schizophrenia. The Journal of Clinical Psychiatry, 79(5). ()
  7. Choudhary, D., Bhattacharyya, S., & Bose, S. (2017). Efficacy and safety of ashwagandha (Withania somnifera (l.) dunal) root extract in improving memory and cognitive functions. Journal of Dietary Supplements, 14(6), 599-612. ()
  8. Choudhary, D., Bhattacharyya, S., & Joshi, K. (2016). Body weight management in adults under chronic stress through treatment with Ashwagandha root extract. Journal of Evidence-Based Complementary & Alternative Medicine, 22(1), 96-106. ()
  9. Dai, T., Jiang, W., Guo, Z., Wang, Z., Huang, M., Zhong, G., ... & Dai, R. (2019). Studies on oral bioavailability and first‐pass metabolism of withaferin A in rats using LC–MS/MS and Q‐TRAP. Biomedical Chromatography, 33(9), e4573. ()
  10. Dar, N. J., Hamid, A., & Ahmad, M. (2015). Pharmacologic overview of Withania somnifera, the Indian ginseng. Cellular and Molecular Life Sciences, 72(23), 4445-4460. ()
  11. Devkar, S., Kandhare, A., Sloley, B., Jagtap, S., Lin, J., Bodhankar, S., . . . Hegde, M. (2015). Evaluation of the bioavailability of major withanolides of Withania somnifera using an in vitro absorption model system. Journal of Advanced Pharmaceutical Technology and Research, 6(4), 159-164. ()
  12. Dongre, S., Langade, D., & Bhattacharyya, S. (2015). Efficacy and safety of Ashwagandha (Withania somnifera) root extract in improving sexual function in women: A pilot study. BioMed Research International, 2015, 1-9. ()
  13. Jahanbakhsh, S. P., Manteghi, A. A., Emami, S. A., Mahyari, S., Gholampour, B., Mohammadpour, A. H., & Sahebkar, A. (2016). Evaluation of the efficacy of Withania somnifera (Ashwagandha) root extract in patients with obsessive-compulsive disorder: A randomized double-blind placebo-controlled trial. Complementary Therapies in Medicine, 27, 25-29. ()
  14. Lopresti, A. L., Drummond, P. D., & Smith, S. J. (2019). A randomized, double-blind, placebo-controlled, crossover study examining the hormonal and vitality effects of Ashwagandha (Withania somnifera) in aging, overweight males. American Journal of Mens Health,13(2). ()
  15. National Institutes of Health. (2019). Livertox: clinical and research information on drug-induced liver injury. Nih. gov https://livertox. nih. Gov. Retrieved from ()
  16. Patel, S. B., Rao, N. J., & Hingorani, L. L. (2016). Safety assessment of Withania somnifera extract standardized for Withaferin A: Acute and sub-acute toxicity study. Journal of Ayurveda and Integrative Medicine,7(1), 30-37. ()
  17. Patil, D., Gautam, M., Mishra, S., Karupothula, S., Gairola, S., Jadhav, S., . . . Patwardhan, B. (2013). Determination of withaferin A and withanolide A in mice plasma using high-performance liquid chromatography-tandem mass spectrometry: Application to pharmacokinetics after oral administration of Withania somnifera aqueous extract. Journal of Pharmaceutical and Biomedical Analysis,80, 203-212. ()
  18. Ramakanth, G., Kumar, C. U., Kishan, P., & Usharani, P. (2016). A randomized, double blind placebo controlled study of efficacy and tolerability of Withania somnifera extracts in knee joint pain. Journal of Ayurveda and Integrative Medicine, 7(3), 151-157. ()
  19. Sharma, A. K., Basu, I., & Singh, S. (2018). Efficacy and safety of ashwagandha root extract in subclinical hypothyroid patients: A double-blind, randomized placebo-controlled trial. The Journal of Alternative and Complementary Medicine, 24(3), 243-248. ()
  20. Singh, N., Bhalla, M., Jager, P. D., & Gilca, M. (2011). An overview on Ashwagandha: A Rasayana (rejuvenator) of ayurveda. African Journal of Traditional, Complementary and Alternative Medicines,8(5S), 208-213. ()
  21. Wang, F., Zhao, J., Bai, J., Gao, K., Cui, D., Chen, Y., ... & Wen, A. (2019). Liquid chromatography-tandem mass spectrometry to assess the pharmacokinetics and tissue distribution of withaferin A in rats. Journal of Chromatography B, 1122, 90-95. ()
  22. Wankhede, S., Langade, D., Joshi, K., Sinha, S. R., & Bhattacharyya, S. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery: A randomized controlled trial. Journal of the International Society of Sports Nutrition, 12(1). ()
  23. Ziegenfuss, T., Kedia, A., Sandrock, J., Raub, B., Kerksick, C., & Lopez, H. (2018). Effects of an aqueous extract of Withania somnifera on strength training adaptations and recovery: The STAR trial. Nutrients, 10(11), 1807. ()

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