Ashwagandha
Ashwagandha is a shrub that grows in Asia and Africa. Its name means “horse smell” in Sanskrit because the roots have a strong scent. It has long been used in traditional medicine as an adaptogen; a substance believed to help the body cope with stress. Today, ashwagandha is mainly taken as root extract in supplements and may help calm the brain, reduce inflammation, and support overall health.
Is this used to correct a deficiency or achieve supramaximal levels?
Supramaximal
Is it taken for life span or health span?
Healthspan, indirect lifespan benefits (chronic stress and poor sleep affect lifespan)
Is it targeting a specific disease? Or general health?
General health
Any genetic involvement?
N/A
Is there a biomarker to track its effects?
Self reported effects or sleep tracking devices
MOA of supplement
Ashwagandha is believed to work by increasing GABA activity in the brain, which has a calming effect, and potentially lowers cortisol levels, the stress hormone. Animal studies show it can promote deep and non-REM sleep, but these effects have not been fully confirmed in humans. Though some studies suggest a 40% reduction in morning cortisol, more research is needed to clarify its mechanisms and confirm these benefits in humans. Overall, while ashwagandha shows promise for stress and sleep, the exact mechanisms remain unclear.
Risk vs reward
+ Well tolerated by most
+ Anecdotally an effective sleep aid
- Many people report no noticeable effects
- Some studies have reported minor GI issues
- Can be quite expensive depending on brand and dose
- Variation in quality of supplementation. There are also different types of extracts
Evidence for it?
Meta analysis shows that Ashwagandha supplementation reduced anxiety and stress compared to placebo in a meta-analysis of 12 RCTs, though the certainty of evidence was low. Benefits for anxiety were seen up to 12,000 mg/day, while stress reduction was most effective at 300–600 mg/day. More high-quality studies are needed to confirm these effects.
RTC of 80 participants. Ashwagandha root extract significantly improved sleep quality and anxiety in both healthy individuals and those with insomnia, with stronger effects seen in the insomnia group. Key improvements included sleep onset latency, sleep efficiency, total sleep time, and mental alertness. The extract was well tolerated, but more studies with bigger populations are needed to confirm and generalise the results.
RCT This study investigated the effects of ashwagandha on anxiety and cortisol levels in stressed adults. Sixty participants took either 240 mg of ashwagandha or a placebo daily for 60 days. The results showed that ashwagandha significantly reduced anxiety, measured by the Hamilton Anxiety Rating Scale (HAM-A), and lowered morning cortisol levels compared to the placebo. These findings suggest that ashwagandha may help alleviate anxiety by influencing the hypothalamic-pituitary-adrenal axis.
Review This review highlights Ashwagandha’s potential cardiovascular benefits, including its ability to counteract oxidative stress and reduce ischemia/reperfusion-induced apoptosis, offering cardioprotective effects. Additionally, the herb shows promise in improving lipid metabolism, which may further support heart health.
Evidence against it?
RCT This randomised, placebo-controlled trial reviewed the effects of ashwagandha supplementation in overweight or mildly obese adults with high stress and fatigue. While ashwagandha did not significantly outperform placebo in reducing perceived stress, it did show a significant reduction in fatigue and an increase in heart rate variability—suggesting improved autonomic nervous system function. Additionally, men experienced a rise in free testosterone and luteinizing hormone. These findings suggest potential anti-fatigue and hormonal benefits of ashwagandha
RCT this 12-week randomized, placebo-controlled trial, ashwagandha (200 mg twice daily) did not significantly reduce perceived stress compared to placebo in overweight or mildly obese adults with high stress. However, it significantly reduced fatigue, increased heart rate variability, and in men, boosted free testosterone and luteinizing hormone levels. Ashwagandha was well-tolerated, suggesting potential anti-fatigue and hormonal benefits.
Best bioavailable form?
Capsule
Advice on taking it?
10–30 mg of withanolides per day