Get Involved
About Us
Our Members

Ashwagandha Root Extract Improves Sleep Quality in People with Insomnia


Reviewed: Langade D, Thakare V, Kanchi S, Kelgane S. Clinical evaluation of the pharmacological impact of ashwagandha root extract on sleep in healthy volunteers and insomnia patients: A double-blind, randomized, parallel-group, placebo-controlled study. J Ethnopharmacol. January 2021;264:113276. doi: 10.1016/j.jep.2020.113276.

Insomnia is a common sleep disorder characterized by difficulty falling asleep, staying asleep, or both. Pharmacotherapy and psychotherapy are the conventional treatment options for insomnia. However, pharmacological treatments can have adverse effects including dependency, and people with insomnia may have difficulty finding or affording psychotherapeutic options due to the lack of practitioners trained in cognitive behavioral therapy for insomnia.

Herbal medicinal approaches can provide an alternative to these conventional treatments. Ashwagandha (Withania somnifera, Solanaceae) root is a popular Ayurvedic herb. It often is used as an adaptogen (a substance that increases the state of nonspecific resistance to stress) and contains constituents such as alkaloids, steroidal lactones, and saponins, which may help alleviate insomnia. However, controlled human clinical trials on the effects of ashwagandha on sleep are lacking. Therefore, the purpose of this randomized, double-blind, placebo-controlled, parallel-group study was to examine the safety and efficacy of ashwagandha root extract for insomnia and anxiety.

People who visited the outpatient facility of the D. Y. Patil Medical College and Hospital in Nerul, Navi Mumbai, India, were recruited for the study. Participants aged 18 to 50 years with and without insomnia were eligible for inclusion. Insomnia was diagnosed based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria. Participants were excluded if they had sleep disorders other than primary insomnia, known clinical illnesses, psychiatric disorders associated with insomnia, or a history of seizures or significant head trauma. Other exclusion criteria included use of tobacco (Nicotiana tabacum, Solanaceae) during night awakenings or any medications on a regular basis except drugs for cardiovascular prophylaxis or diabetes management, among other criteria.

Participants were separated into two study arms: Arm-A (healthy participants) and Arm-B (participants with insomnia). Both study arms were randomly assigned to receive either ashwagandha root extract capsules (KSM-66®, standardized to a withanolide content of > 5%; Ixoreal Biomed Inc.; Los Angeles, California) or placebo (starch capsules). The treatment and placebo capsules were the same size, shape, odor, color, and taste. How the placebo capsules were made to have a similar odor and taste as the root extract was not described. Participants were instructed to take one 300-mg capsule twice daily with milk or water for eight weeks.

The primary outcome measure was the change in sleep onset latency (SOL, the length of time it takes to transition from full wakefulness to sleep) assessed through actigraphy (a non-invasive technique that continuously measures cycles of activity and rest). The secondary outcome measures were total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE, the ratio of total time spent asleep to the total time spent trying to sleep). The Pittsburgh Sleep Quality Index (PSQI) and Hamilton Anxiety Scale (HAM-A) questionnaires also were administered, along with scales that assessed mental alertness on rising and sleep quality. All outcome measurements were assessed at baseline, week one, week four, and week eight.

Of the 116 participants who were assessed for eligibility, 64 were healthy and 52 were diagnosed with insomnia. Eighty were recruited (n = 40 in both arms). Of these, 36 healthy participants (n = 18 ashwagandha, n = 18 placebo) and 37 participants with insomnia (n = 20 ashwagandha, n = 17 placebo) were included in the per-protocol analysis. No significant differences between the groups were observed for age, body mass index (BMI), blood pressure, pulse rate, or respiratory rate. At baseline, SOL and WASO were higher, and TST, total time in bed, and SE were significantly lower (P < 0.0001) in the participants with insomnia (Arm-B) compared with the healthy participants (Arm-A).

In both Arm-A and Arm-B, SOL and WASO significantly decreased with ashwagandha versus placebo (P < 0.0001) after eight weeks. Additionally, increases in TST, total time in bed, and SE were observed over eight weeks in both the ashwagandha and placebo groups (P < 0.0001). A significant decrease (improvement) in mean PSQI scores from baseline was observed for the ashwagandha treatment groups in both Arm-A and Arm-B (P < 0.0001 for both). A significant decrease (improvement) in HAM-A scores in the ashwagandha group in Arm-B was observed, whereas no improvement was found in the ashwagandha group in Arm-A. The mental alertness outcome in the ashwagandha group in both arms was significantly improved compared with placebo (P < 0.0001). The sleep quality assessment outcome also was significantly improved in the ashwagandha group in both arms, especially in participants with insomnia compared with placebo (P < 0.0001). No adverse events were reported in the study.

Ashwagandha supplementation for eight weeks was associated with significant improvements in measures of sleep quality, including SOL, WASO, and total PSQI scores, in both healthy participants and participants with insomnia, with a more pronounced effect in participants with insomnia. Other measures, including SE, TST, and mental alertness on rising, also were improved from baseline with ashwagandha. To the authors’ knowledge, this is the first clinical trial conducted to assess the effects of ashwagandha root extract on sleep quality in both healthy participants and participants with insomnia.