Verma N, Gupta SK, Tiwari S, Mishra AK. Safety of ashwagandha root extract: A randomized, placebo-controlled, study in healthy volunteers. Complement Ther Med. March 2021;57:102642. doi: 10.1016/j.ctim.2020.102642.
Ashwagandha (Withania somnifera, Solanaceae) root has been used for centuries for its health benefits, which include immunomodulatory, stress-reducing, antioxidant, cardioprotective, anti-inflammatory, and antineoplastic activities. Although its efficacy has been demonstrated, few studies on the safety of ashwagandha have been reported. These authors conducted a randomized, double-blind, placebo-controlled clinical study to evaluate the safety of KSM-66® (Ixoreal Biomed Inc.; Los Angeles, California), an ashwagandha root extract, in healthy participants.
The study was conducted at King George's Medical University and at MV Hospital and Research Centre (Lucknow, Uttar Pradesh, India) as the safety arm of a larger trial that evaluated the impact of ashwagandha on the participants' immune system and its effects on muscle mass, strength, and stamina. Eligible participants were considered healthy, as determined by their medical history and physical, clinical, and laboratory examinations. Exclusion criteria included the following: pregnancy or breastfeeding; history of hypersensitivity to ashwagandha; use of medications, steroids, or supplements; history of drug abuse; smoking > 10 cigarettes or > 14 g alcohol daily; any clinical abnormalities (unspecified); current or recent participation in another trial; any history of heart disease, diabetes, stroke, neurological disorders, or depression.
Forty male-identifying and 40 female-identifying adults aged 18-45 years were enrolled in the study. Participants were evenly randomized to take 300 mg of KSM-66 or 300 mg of a starch placebo twice daily for eight weeks. The ashwagandha root extract KSM-66 is standardized to 5% withanolides.
Safety assessments at baseline and at the end of the study included evaluations of hemoglobin, neutrophil and platelet counts, alkaline phosphatase, serum glutamic oxaloacetic transaminase/aspartate aminotransferase, and serum glutamic pyruvic transaminase/alanine aminotransferase. The authors cite a case report of thyrotoxicosis associated with the use of ashwagandha in animals that suggested that the herb may induce thyroid hormone levels and explained that they were also assessing the serum levels of thyroid-stimulating hormone, triiodothyronine, and thyroxine in participants. All participants were asked to report adverse effects.
Mean ages of the participants were 31.80 ± 8.91 years in the ashwagandha group and 29.22 ± 7.51 years in the placebo group. Demographic characteristics were similar between the two groups. Vital signs of the participants were within normal limits at baseline and remained so during the study. All participants completed the study.
Hematological and biochemical safety measures, including thyroid function tests, remained within acceptable ranges throughout the study in the ashwagandha group, and no significant differences were observed between the two groups. No adverse effects were reported during the study.
The authors conclude that the use of ashwagandha root extract was found to be safe, tolerable, and free from any unwanted effects in healthy adult participants. They note that further large-scale study is required to generalize the obtained outcomes. The authors declare no conflicts of interest.