A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults

Objective: Non-restorative sleep (NRS) affects 10% people worldwide, leading to poor sleep quality, as well as physical and cognitive fatigue. This is the first human study in which an extract of ashwagandha (Withania somnifera Dunal L.) was evaluated for effects in improving overall sleep quality in subjects with NRS.

Methods: In this randomized, double-blind, placebo-controlled trial, 150 healthy subjects scoring high on non-restorative sleep measures were given 120 mg of standardized ashwagandha extract (Shoden®) once daily for six weeks. Subjects were evaluated using the Restorative Sleep Questionnaire-weekly version and World Health Organization Quality of Life-Bref (WHOQOL) scale. Sleep actigraphy was used to measure the onset of sleep latency, sleep efficiency, total sleep time and wake after sleep onset. Safety of the treatment was determined by testing of vitals, hematology, biochemistry and urinalysis.

Results: A total of 144 subjects completed the study, with no dropouts due to adverse events. A 72% increase in self-reported sleep quality was found for the treatment group, compared with 29% in the placebo group (p < 0.001). Based on activity monitoring data, the treatment group showed significant improvement in sleep efficiency (SE) (p < 0.01), total sleep time (p < 0.001) and sleep latency (p < 0.01) and wake after sleep onset (WASO) (p < 0.05) versus placebo after six weeks. In the ashwagandha group quality of life (QOL) scores showed significant improvement in physical (p < 0.001), psychological (p < 0.001), and environment domains (p < 0.01).

Conclusions: Supplementation with the standardized ashwagandha extract for six weeks improved the overall quality of sleep by significantly improving the NRS condition in healthy subjects. No treatment related adverse events were reported in the study.

Trial registration: Clinical Trials Registry-India (www.ctri.nic.in). Registration number: CTRI/2017/02/007801.

Keywords: Actigraphy; Ashwagandha; Non restorative sleep; RSQ; Sleep quality.