Ashwagandha dosage: how much KSM-66 per day?
Dosage is where most people get ashwagandha wrong. Either they take too little to notice anything, or they assume more is always better. Here is what the studies actually used – and how to translate that into capsules.
How much ashwagandha per day?
The benchmark is 240 to 600 mg of standardised root extract per day. That is the range that has produced results in placebo-controlled trials. For KSM-66, the most studied extract, most trials sit at 600 mg per day. If you stay within that range, you are on well-tested ground.
Note that this applies to extract, not raw root powder. Powder is much weaker and is dosed in grams – more on that further down.
Unlike vitamins and minerals, there is no official reference intake for ashwagandha. Neither EFSA nor national nutrition guidelines specify a daily amount, because the herb is not a nutrient. The study doses are therefore the best benchmark available.
Which doses have been used in the studies?
The table shows the doses behind the most cited results.
| Goal | Dose per day | Study |
|---|---|---|
| Stress and cortisol | 600 mg KSM-66 | Chandrasekhar 2012, 60 days |
| Sleep | 600 mg KSM-66 | Langade 2019, 10 weeks |
| Anxiety and stress | 240 mg extract | Lopresti 2019, 60 days |
| Strength and training | 600 mg KSM-66 | Wankhede 2015, 8 weeks |
| Stress resilience, dose comparison | 250 or 600 mg | Salve 2019, 8 weeks |
An interesting detail from the 2019 dose comparison: both 250 and 600 mg lowered cortisol and perceived stress, but 600 mg gave the clearest effect. Going above 600 mg, however, has not shown better results in studies. Doubling the dose does not double the effect – it only raises the risk of stomach upset.
Extract or powder – why does it matter?
Raw ashwagandha powder contains roughly 0.3 per cent withanolides, the active compounds. A standardised extract like KSM-66 contains at least 5 per cent. The difference is more than tenfold.
That means 600 mg of extract corresponds to several grams of raw powder. With a standardised extract you also know exactly what each capsule contains – powder varies from harvest to harvest. Our ashwagandha contains 500 mg of KSM-66 per capsule, which makes dosing simple.
KSM-66 root extract with 500 mg per capsule – GMP-manufactured and third-party tested.
See current price »One or two doses per day?
In most studies the daily dose was split: 300 mg in the morning and 300 mg in the evening. But there is nothing to suggest the split is decisive. What matters is the total daily dose, taken every day.
In practice that means: one 500 mg capsule once a day is enough for many people. If you want to mirror the 600 mg used in the studies, take one capsule in the morning and one in the evening. Which time of day suits you best depends on your goal – we cover that in the article on when to take ashwagandha.
How long can you take ashwagandha?
The studies ran for 8 to 12 weeks, and daily intake was well tolerated during that time. However, safety data covering several years of continuous use does not exist.
A common approach is therefore: take the supplement daily for two to three months, evaluate the effect, then build in a break of a few weeks if you want to continue. That is not a rule from the research, but a sensibly cautious way to use the herb.
Can you take too much ashwagandha?
Doses above 600 mg of extract per day add nothing according to the studies – but they do increase the risk of stomach upset, loose stools and drowsiness. At very high doses, isolated cases of liver effects have been reported, usually with products of unclear quality.
Stick to the study doses. And do read our overview of ashwagandha side effects before you start, especially if you take medication. Pregnant and breastfeeding women should avoid it entirely, and if you have a medical condition or take medicines, your doctor or pharmacist is the right first stop.
If you forget a dose
No panic. Take the next dose as usual – do not double up to compensate. One missed day does not undo the effect, but several missed days a week does. The effect is built on steady intake over time.
The easiest trick is to tie the capsule to a fixed habit: put the jar next to the coffee maker or your toothbrush. The people who manage to keep the routine going for eight weeks are also the ones who can tell whether the supplement makes a difference.
Tea and powder – do they work too?
Ashwagandha is also sold as loose powder for smoothies and tea. It works in theory, but the dosing becomes a lottery. The withanolide content of raw powder varies widely between batches, and the taste is bitter and harsh.
If you want to compare your dose with the study results, standardised capsules are the only practical choice. You know what you are getting, every day, without having to mask any flavour.
Three practical dosing tips
- Take the capsule with food. It reduces the risk of nausea and may aid absorption.
- Be consistent. The effect builds up over weeks. An occasional dose makes no difference.
- Count withanolides, not just milligrams. Compare products on the extract's standardisation. In our guide to the best ashwagandha you can see how products differ in dose, extract and price.
Frequently asked questions
How many 500 mg KSM-66 capsules should I take?
One capsule a day is a good start and sits close to the 240 to 500 mg that produced effects in several studies. If you want to reach the 600 mg used in most KSM-66 studies, take one capsule in the morning and one in the evening. Start low the first week and notice how your body responds.
Do you need to take breaks from ashwagandha?
No, the research imposes no such requirement. The studies ran for 8 to 12 weeks with daily intake and no problems. Since long-term data is lacking, many people still choose to pause for a few weeks after two to three months. That is a precaution rather than a rule, and you lose nothing by doing it.
When do you notice the effect of the right dose?
Expect four to eight weeks of daily use. In the 2012 stress study, the large drop in cortisol was measured after 60 days, and the sleep studies ran for eight to ten weeks. If you notice nothing after two months on 600 mg per day, it is reasonable to reconsider whether ashwagandha is right for you.
Can I combine ashwagandha with magnesium?
Yes, the combination is common and there are no known negative interactions between them. Many people take both in the evening, since magnesium contributes to normal muscle function and to a reduction of tiredness and fatigue, while ashwagandha has been linked to better sleep in studies. If you take medication, check with your pharmacist first, as always.
Sources
- Chandrasekhar K et al. (2012). A prospective, randomized double-blind, placebo-controlled study of ashwagandha root extract in reducing stress and anxiety. Indian J Psychol Med.
- Langade D et al. (2019). Efficacy and safety of ashwagandha root extract in insomnia and anxiety. Cureus.
- Lopresti AL et al. (2019). An investigation into the stress-relieving and pharmacological actions of an ashwagandha extract. Medicine (Baltimore).
- Wankhede S et al. (2015). Examining the effect of Withania somnifera supplementation on muscle strength and recovery. J Int Soc Sports Nutr.
- Salve J et al. (2019). Adaptogenic and anxiolytic effects of ashwagandha root extract in healthy adults. Cureus.
- Cheah KL et al. (2021). Effect of ashwagandha extract on sleep: a systematic review and meta-analysis. PLoS One.
- Swedish Food Agency – on dietary supplements.