What ashwagandha actually does, by the evidence

What people ask us next.

Q01

Does ashwagandha actually work?

For short-term self-reported stress and anxiety, the pooled data say yes with low confidence. Twelve randomised controlled trials in 1,002 participants found reduced anxiety (SMD -1.55) and stress (SMD -1.75) versus placebo, but with heterogeneity of 93.8 and 83.1 percent and a certainty of evidence rated low by the authors, who called for further high-quality studies (Akhgarjand et al. 2022). For testosterone, vitality, or body composition, there is no comparable pooled support.

Q02

How much ashwagandha should you take?

The dose window with pooled support is 300 to 600 mg a day of a standardised root extract, identified by the dose-response analysis in the 12-trial meta-analysis (Akhgarjand et al. 2022). That matches the trials: 300 mg twice daily for 60 days (Chandrasekhar et al. 2012), and 125 or 300 mg twice daily for eight weeks (Salve et al. 2019). Doses well above that range have not been shown to work better; they are simply further from what was tested.

Q03

Does ashwagandha lower cortisol?

In the two most-cited trials, yes. Sixty-four adults with chronic stress taking 300 mg twice daily for 60 days had a substantial reduction in serum cortisol versus placebo (P=0.0006) alongside improvement on all stress scales (Chandrasekhar et al. 2012). Sixty stressed adults had cortisol reductions at both 250 mg and 600 mg a day over eight weeks (Salve et al. 2019). Note that the crossover trial in aging overweight men found no significant between-group cortisol difference (Lopresti et al. 2019), so the effect is not universal across populations.

Q04

Does ashwagandha raise testosterone?

One trial found the marker moved and nothing else did. In overweight men aged 40 to 70 with mild fatigue, eight weeks of an extract delivering 21 mg of withanolide glycosides daily was associated with an 18 percent greater rise in DHEA-S and a 14.7 percent greater rise in testosterone than placebo, with no significant between-group differences in fatigue, vigour, cortisol, estradiol, or sexual well-being; the authors asked for larger samples (Lopresti et al. 2019). That is a hormonal marker result, not a clinical one.

Q05

Is ashwagandha bad for your liver?

It carries a rare but documented risk. Five cases of liver injury attributed to ashwagandha-containing supplements were described from Iceland and the US Drug-Induced Liver Injury Network, all with jaundice plus nausea, lethargy, pruritus, and abdominal discomfort after 2 to 12 weeks of use, with cholestatic or mixed injury and prolonged itching and hyperbilirubinaemia for 5 to 20 weeks. No patient developed hepatic failure and liver tests normalised in 1 to 5 months (Björnsson et al. 2020).

Q06

How long does ashwagandha take to work?

The trials assess at eight weeks or 60 days, and that is the interval to judge it on. The 64-person trial measured outcomes on day 60 with telephone check-ins on days 15, 30, and 45 (Chandrasekhar et al. 2012); the dose-ranging trial assessed at four and eight weeks (Salve et al. 2019). Nothing in this literature supports an acute or same-day effect, so a two-week trial is not a test. Given the hepatic case latency of 2 to 12 weeks, that is also the window in which to watch for jaundice.