Ashwagandha is an evergreen shrub that grows in Asia and Africa. The shrub's roots and berries are used to make an Ayurvedic medicine. Ayurveda is the traditional medical system of India. The name is derived from Sanskrit and translated as "smell of the horse."
(See also Overview of Dietary Supplements.)
Claims
Ashwagandha, also known as Withania somnifera, is said to enhance muscle strength, reduce stress, and improve sleep. There has been interest in ashwagandha use for osteoarthritis due to some preliminary chondroprotective activity.
Evidence
There is insufficient evidence that ashwagandha reduces stress, improves sleep, or is effective for treating any disease (1).
Ashwagandha in a combination supplement product demonstrated potential efficacy in relieving symptoms of osteoarthritis, but it is unclear if the benefit was due to ashwagandha or one of the other ingredients or the combination (2).
Ashwagandha was evaluated in a 12-week, randomized, placebo-controlled trial in 38 young, active males doing resistance training. The study reported that the ashwagandha group had significant improvements in muscle strength, bench-press power, squats, and recovery scores (3).
Adverse Effects
Adverse effects of ashwagandha may include diarrhea, headache, sedation, or nausea. Liver problems may occur. Ashwagandha may increase testosterone levels (Adverse effects of ashwagandha may include diarrhea, headache, sedation, or nausea. Liver problems may occur. Ashwagandha may increase testosterone levels (4).
Ashwagandha should not be used during pregnancy or breastfeeding.
Drug Interactions
Ashwagandha can interact with thyroid hormones and antihyperglycemic, antihypertensive, immunosuppressant, and sedative drugs. (See table Some Possible Dietary Supplement–Drug Interactions.)
References
1. Speers AB, Cabey KA, Soumyanath A, Wright KM: Effects of Withania somnifera (ashwagandha) on stress and the stress-related neuropsychiatric disorders anxiety, depression, and insomnia. Curr Neuropharmacol 19(9):1468-1495, 2021. doi: 10.2174/1570159X19666210712151556
2. Chopra A, Lavin P, Patwardhan B, et al: A 32-week randomized, placebo-controlled clinical evaluation of RA-11, an Ayurvedic drug, on osteoarthritis of the knees. J Clin Rheumatol 10(5):236-245, 2004. doi:10.1097/01.rhu.0000138087.47382.6d
3. Ziegenfuss TN, Kedia AW, Sandrock JE, et al: Effects of an aqueous extract of Withania somnifera on strength training adaptations and recovery: The STAR Trial. Nutrients 10(11):1807, 2018. doi:10.3390/nu10111807
4. Lopresti AL, Drummond PD, Smith SJ: A randomized, double-blind, placebo-controlled, crossover study examining the hormonal and vitality effects of ashwagandha (Withania somnifera) in aging, overweight males. Am J Mens Health 13(2):1557988319835985, 2019. doi:10.1177/1557988319835985
