Best Ashwagandha Supplements
Ashwagandha is the best-studied herb in the adaptogen category. The trials are encouraging and modest, and there is a rare liver risk every buyer should know about.
Quick Summary
A standardized root extract around 300 to 600 mg a day is what the stress and sleep trials used. Know the liver warning signs before you start.
What the research shows
| Feature | Evidence | Limits |
|---|---|---|
| Perceived stress | 12 randomized trials, 1,002 people, lower scores than placebo. | Studies differed widely. Many were industry-funded. Mostly 6 to 12 weeks. |
| Sleep | 5 trials, 400 people, a small benefit. | Clearer at 600 mg a day or more for at least 8 weeks. Self-reported. |
| Testosterone | One crossover trial: 14.7% greater testosterone increase and 18% greater DHEA-S increase than placebo. | 57 men enrolled, 50 finished 8 weeks, 43 finished 16 weeks. No significant difference in fatigue, vigor, sexual well-being, cortisol, or estradiol. |
Stress and sleep counts are from Akhgarjand 2022 (doi:10.1002/ptr.7598) and Cheah 2021 (PMC8462692). We did not re-download those PDFs on October 21. The testosterone row is from Lopresti 2019, which we did re-open.
The testosterone trial, with its limits
Lopresti and colleagues (American Journal of Men's Health, 2019, doi:10.1177/1557988319835985) ran a crossover study in overweight men aged 40 to 70 with mild fatigue. The extract was Shoden, 21 mg of withanolide glycosides a day, 8 weeks per period. Testosterone and DHEA-S rose more than with placebo. Fatigue, vigor, sexual well-being, cortisol, and estradiol did not differ between groups. The extract supplier did not design, analyze, or write the paper. This is one small trial, not a reason to expect a change in how you feel.
Side effects, including liver injury
Stomach upset, diarrhea, and drowsiness are the common complaints. Thyroid hormone levels can change. Ask first if you have a thyroid condition or take thyroid medicine.
Bjornsson and colleagues published five cases of liver injury attributed to ashwagandha supplements: three from Iceland (2017 to 2018) and two from the US Drug-Induced Liver Injury Network (2016). All developed jaundice after a latency of 2 to 12 weeks. Injury was cholestatic or mixed. No patient developed liver failure. Tests normalized within 1 to 5 months in four patients (PMC8041491). The NIH LiverTox monograph text would not load on October 21, 2026, so we are not quoting it separately.
Stop and get medical care for yellow skin or eyes, dark urine, or itching. Avoid ashwagandha if you already have liver disease. Also ask first in pregnancy, with autoimmune disease, with sedatives or immunosuppressants, and before surgery.
The label we could verify
| Feature | Dose | Testing | Price |
|---|---|---|---|
| Double Wood KSM-66 | Organic root-only extract, 5% withanolides, 600 mg per 2 capsules, 120 capsules. | Every batch tested by ISO/IEC 17025 labs. COAs published, brand-stated. We did not open a certificate. | $19.95 |
Gaia and Goli product feeds did not state milligrams per serving in this check, so those rows are omitted rather than filled with guesses.
Who this is for
Who Might Like This
- ✓Healthy adults looking for modest support with perceived stress or sleep, who will stop if liver symptoms appear.
Who Should Consider Alternatives
- ×Thyroid disease, autoimmune disease, sedatives, or immunosuppressants. Ask first.
- ×Pregnancy, existing liver disease, or a past reaction to ashwagandha.
Our verdict
Ashwagandha has better trial support than most herbs for stress and sleep scores, and the effects are modest. Double Wood's KSM-66 label was the clearest one we could read: 600 mg, 5% withanolides, $19.95, with a brand-stated testing program we did not independently open. Know the liver warning signs.
Related guides
Sources
How we checked
On October 21, 2026, we re-opened the Bjornsson case series (five patients, jaundice after 2 to 12 weeks, no liver failure) and confirmed Double Wood KSM-66 at $19.95, 600 mg per 2 capsules, 5% withanolides, root-only, with a brand-stated ISO/IEC 17025 testing line.
Lopresti's 2019 trial was checked against the paper: 57 enrolled, 50 finished the first 8 weeks, 43 finished 16 weeks, Shoden at 21 mg withanolide glycosides, 14.7% greater testosterone increase, 18% greater DHEA-S increase, and no between-group difference on fatigue, vigor, sexual well-being, cortisol, or estradiol.
The 12-trial and 5-trial counts were not re-downloaded as PDFs in this build. Gaia and Goli doses were not on the feeds we opened, so they are omitted. LiverTox text would not load.
Frequently Asked Questions
A standardized root extract around 300 to 600 mg a day, with testing you can open. On October 21, 2026, Double Wood KSM-66 stated 600 mg per 2 capsules and 5% withanolides at $19.95. We did not confirm Gaia or Goli milligrams.
Stomach upset and drowsiness are the common ones. Rare liver injury has been documented, with jaundice starting 2 to 12 weeks after use in a five-patient series. Stop and see a doctor if that happens.
In one small trial of overweight men aged 40 to 70, testosterone and DHEA-S rose more than with placebo. Fatigue, vigor, and sexual well-being did not. That is not a performance claim.
Only if they contain a trial-level dose. We could not confirm a gummy milligram amount, so we are not recommending one.
The stress trials mostly ran 6 to 12 weeks. The sleep analysis found a clearer signal after 8 weeks at 600 mg a day or more.
Ashwagandha has more trials. Shilajit's evidence is narrower. See the shilajit guide.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Evident does not sell any of these products and uses no affiliate links.