Health Reference LibraryHow much ashwagandha should I take, and can you take too much?
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
Two hundred and forty to six hundred milligrams a day of a standardised root extract, most often 300 mg twice a day or 600 mg once for eight weeks, is what the stress and sleep trials used, and the withanolide content on the label matters more than the milligrams. Ashwagandha is a herb with no reference intake and no upper limit, and safety beyond three months has not been studied, so take it as a defined course of eight to twelve weeks and then stop and judge. Rare liver injury has been reported with ashwagandha products, it is not for pregnancy, and anyone whose GP manages a thyroid condition or their mood asks first.
Dose calculator: capsules to reach your ashwagandha target
Enter the daily amount of ashwagandha you are aiming for and see how many servings of each Nutri Tailor product reach it. Nothing you enter leaves this device. No AI is used.
This tool does arithmetic on the label figures. It is not personal dosing advice and it knows nothing about your history or blood results. The reference intake, the safe upper guide and the trial doses are on this page; talk to your GP or a registered nutritional therapist before changing what you take.
Effective dose
The reference intake is none; ashwagandha is a herb, not a nutrient, and has no reference intake. The stress and sleep trials used 240 to 600 mg a day of a standardised root extract, most often 300 mg twice a day or 600 mg once, for eight weeks. What matters is the withanolide content on the label, because 600 mg of a weak powder and 300 mg of a concentrated extract are not the same dose. Take it for a defined course of eight to twelve weeks, then stop and see what changed.
Safety profile
How much is too much: no upper limit has been set; the trials used 240 to 600 mg a day of standardised root extract for eight to twelve weeks, and safety beyond three months has not been studied. Ashwagandha is well tolerated in the trials, with drowsiness and stomach upset the usual complaints. Two things to know: rare cases of liver injury have been reported with ashwagandha products, so stop and see your GP if you notice yellowing, dark urine or persistent nausea; and it should not be taken in pregnancy. Anyone under the care of a GP for a thyroid condition or whose GP manages their mood asks first. It is not a supplement to take indefinitely.
Guideline positions
NHS vitamins and minerals guidance for ashwagandha. NIH Office of Dietary Supplements fact sheet for ashwagandha where one exists. The trial doses quoted above are from the sources listed on this page.
Practical framework
Capsules to reach the dose, from the Nutri Tailor range, all made in the UK: [ashwagandha capsules](/products/ashwagandha), 450 mg of a 10 to 1 root extract standardised to 1.5 percent withanolides per capsule, one to two a day for a course of eight to twelve weeks. To read your own result against the UK ranges, use the free blood test result interpreter. This is a summary of published research, not personal health advice. Talk to your GP or a registered nutritional therapist before changing what you take, especially if you are pregnant, have a diagnosed condition or are under ongoing care.
Common misconceptions
That more ashwagandha works faster: above the doses the trials used there is no extra effect, only more side effects. That the front of the bottle states the dose: read the per capsule figure and the serving size on the back. That the NHS figure is a toxic threshold: it is the level below which harm is unlikely, which is a different thing.
Sources
- 2026. Does ashwagandha work for stress and sleep, and what dose did the trials use?. Nutri Tailor Health Reference Library.