Benefits
Perceived stress scores in stressed adults
In an 8-week double-blind trial funded by Natreon, 131 adults with chronic stress took 125, 250 or 500 mg/day of Sensoril or placebo. All three doses lowered Perceived Stress Scale, anxiety and depression rating scores more than placebo, with larger stress-score drops at higher doses. Only 98 people completed the per-protocol analysis.
Cortisol and other stress markers
In the same 8-week trial, all three Sensoril doses lowered blood cortisol, ACTH and salivary alpha-amylase compared with placebo. Cortisol was not lowered further at higher doses. These are markers measured in one maker-funded trial.
Sleep quality scores in stressed adults
As a secondary outcome of the 8-week stress trial, a sleep rating scale improved at all three doses and the Pittsburgh Sleep Quality Index improved at 250 and 500 mg compared with placebo. This is a single maker-funded trial in stressed adults, not a study of people with sleep problems.
Strength gains with resistance training
In a 12-week double-blind trial funded by Natreon, 38 recreationally active men doing resistance training took 500 mg/day of Sensoril or placebo. Squat and bench press strength rose more with Sensoril. Power, cycling time trial and recovery scores improved only within the Sensoril group, not versus placebo.
Working memory and reaction time in an adjunctive trial
In an 8-week double-blind trial, 60 adults with bipolar disorder in remission took 500 mg/day of Sensoril or placebo alongside their usual medicines; 53 completed. Sensoril improved 3 of many cognitive tasks, including a working memory test and a reaction time measure. The authors called the results preliminary.
Knee joint comfort scores
In a 12-week double-blind trial, 60 people with knee joint pain took Sensoril at 125 or 250 mg twice daily, or placebo. Both doses reduced WOMAC pain, stiffness and function scores and a knee swelling index versus placebo, with the higher dose working sooner. Natreon supplied the capsules.
Mechanism of action
Stress hormone (HPA axis) markers
In the 8-week stress trial, Sensoril lowered cortisol and ACTH, hormones of the hypothalamic-pituitary-adrenal (HPA) axis that drive the stress response, and the authors attribute its effect to modulation of this axis. Exactly how the extract acts on the axis is not known.
Withanolides and other compounds
Withanolides are steroid-like compounds considered the main active constituents of ashwagandha. Sensoril's water extraction of root and leaf yields withanolide glycosides and oligosaccharides; which compounds drive the effects seen in trials has not been established.
Inflammatory markers
In the stress trial, the 250 and 500 mg doses lowered IL-6, TNF-alpha and hs-CRP in a mixed-model analysis, and all doses lowered IL-1 beta, compared with placebo. These are blood markers from one trial, not evidence of an effect on any disease.
Clinical trials
8-week randomized, double-blind, placebo-controlled trial of 125, 250 or 500 mg/day, funded by Natreon (Pandit et al. 2024, Nutrients)
131 adults aged 18 to 60 with chronic stress (Perceived Stress Scale score of 28 or more) in Kolkata, India; 98 in the per-protocol analysis.
All doses lowered Perceived Stress Scale, HAM-A and HAM-D scores and cortisol, ACTH and salivary amylase versus placebo, with dose-related differences in stress score. As secondary outcomes, a sleep rating scale improved at all doses and the PSQI at 250 and 500 mg. Dropout was high, partly due to COVID-19, and no serious adverse events were reported.
12-week randomized, double-blind, placebo-controlled trial of 500 mg/day, product and funding from Natreon (Ziegenfuss et al. 2018, Nutrients)
38 recreationally active men (19 per group) following a 4-day-per-week resistance training program.
Squat 1-RM rose 19.1 kg versus 10.0 kg on placebo (p=0.009) and bench press 12.8 kg versus 8.0 kg (p=0.048). Other body composition, recovery and mood measures did not differ between groups; power, time trial and recovery improved only within the Sensoril group. Well tolerated.
8-week randomized, double-blind, placebo-controlled trial of 500 mg/day added to usual treatment, registered as NCT00761761 (Chengappa et al. 2013, J Clin Psychiatry)
60 euthymic adults with bipolar disorder enrolled; 53 completed (24 Sensoril, 29 placebo).
Sensoril improved digit span backward (a working memory test, p=0.035), Flanker neutral reaction time (p=0.033) and a social cognition rating (p=0.045) versus placebo; the other cognitive tasks did not differ. Mood stayed stable and adverse events were minor. The authors called the results preliminary.
12-week randomized, double-blind, placebo-controlled trial of 125 mg or 250 mg twice daily, capsules supplied by Natreon (Ramakanth et al. 2016, J Ayurveda Integr Med)
60 patients with knee joint pain and discomfort.
Both doses reduced modified WOMAC and knee swelling index scores versus placebo and baseline, and pain, stiffness and disability ratings fell; the 250 mg dose acted earliest (by 4 weeks). All treatments were well tolerated.