The most effective dose of ashwagandha for stress and anxiety is 300 to 600 mg per day of a root extract standardized to around 5% withanolides. That range comes from an international psychiatric taskforce recommendation and aligns with clinical trials where benefits were consistently greater at 500 to 600 mg per day compared to lower doses. But getting the dose right is only part of the picture. The form you choose, when you take it, and how long you stay on it all affect your results.
Choosing the Right Form
Ashwagandha supplements come as root powder, root extract capsules, gummies, and liquid tinctures. Standardized root extracts are the most reliable option because their active compounds (called withanolides) are measured and consistent from batch to batch. Raw root powder requires much higher amounts to get the same effect. In one trial, participants used 12,000 mg of whole root granules per day, which is equivalent to just 6,000 mg of root powder, far more than anyone wants to swallow in capsules.
Three patented extracts dominate the market, and each has a slightly different profile:
- KSM-66 is a root-only extract designed to preserve the natural ratio of compounds found in the root. It tends to feel more energizing and has clinical data supporting cognitive function, stress management, endurance, and recovery.
- Sensoril uses both root and leaf material and is higher in compounds called glycowithanolides. Most people find it more calming, which makes it a better fit if your main goal is sleep or anxiety relief.
- Shoden contains at least 35% withanolides, far more concentrated than the other two. It shows bioactivity at lower doses, so capsules are typically smaller (around 120 to 240 mg).
Any of these can work well. The key is matching the extract to your goal: KSM-66 if you want daytime stress support without drowsiness, Sensoril if sleep and calm are the priority, or Shoden if you prefer a lower-volume capsule.
How Much to Take
Clinical trials have tested doses ranging from 240 mg to 1,250 mg per day, but the sweet spot for most people is 300 to 600 mg of a standardized extract. If you’re new to ashwagandha, starting at 300 mg per day for the first week or two lets you gauge how your body responds before increasing.
Pay attention to the withanolide percentage on the label. A capsule standardized to 5% withanolides at 600 mg delivers 30 mg of withanolides. A Shoden capsule at 35% withanolides delivers similar active compounds in a much smaller pill. The withanolide content matters more than the total milligrams of powder in the capsule, so comparing products by weight alone can be misleading.
When to Take It
There is no single “best” time of day established by research. Most clinical trials simply instruct participants to take their dose once or twice daily with meals, without specifying morning or evening. In practice, timing depends on your goal and how the supplement affects you personally.
If you’re taking ashwagandha primarily for daytime stress and focus, a morning dose with breakfast is a reasonable starting point. If sleep quality is your main concern, taking it in the evening (about an hour before bed) makes more sense, especially with a calming extract like Sensoril. Some trials used a split dose, such as one capsule in the morning and one in the evening. Splitting can help maintain steadier levels throughout the day and may reduce any mild stomach discomfort that occasionally comes with a full dose on its own.
Taking ashwagandha with food is generally recommended. It’s a fat-soluble extract, and a small amount of dietary fat can improve absorption while buffering your stomach.
How Long to Use It
Most clinical trials run 8 to 12 weeks, and that’s a practical window for your own use as well. Stress and sleep benefits typically emerge within the first few weeks, though some people notice changes sooner. After 8 to 12 weeks, consider taking a break of 2 to 4 weeks before restarting.
The reasoning behind this cycling approach is threefold. First, some people report that the effects feel less noticeable over time, and a break can help restore responsiveness. Second, periodic pauses reduce the chance of side effects accumulating. Third, stopping for a few weeks gives you a chance to honestly assess whether the supplement is still doing something useful or whether the underlying stress has resolved on its own.
If you feel significantly better after a cycle and have no side effects, you can either continue with periodic check-ins or follow a structured on/off schedule. Restarting only makes sense if the symptoms you were targeting actually return during your break.
Safety and Side Effects
Ashwagandha is well tolerated by most healthy adults at recommended doses. The most common side effects are mild: stomach upset, drowsiness, or loose stools, particularly at higher doses or on an empty stomach.
Liver safety has received some attention in recent years. A 2025 meta-analysis in Frontiers in Nutrition reviewed the evidence and found that reported cases of liver toxicity were rare and almost always involved confounding factors like pre-existing liver conditions, use of multiple supplements, or unusually high doses. In clinical monitoring, only mild, reversible elevations in liver enzymes were observed in a small number of participants, and those normalized after stopping the supplement. Notably, the potentially problematic compounds identified in ashwagandha were not predicted to be present in root-only extracts, which is one reason root extracts are generally preferred over leaf-based products.
Who Should Avoid Ashwagandha
Ashwagandha is not appropriate for everyone. You should avoid it if you are pregnant or breastfeeding, have an autoimmune disease, or have a thyroid disorder. It can stimulate thyroid hormone production, which is dangerous if your thyroid is already overactive or if you’re on thyroid medication.
It also has the potential to interact with several categories of medication: drugs for diabetes and high blood pressure, immunosuppressants, sedatives, and anti-seizure medications. Because ashwagandha may increase testosterone levels, people with hormone-sensitive prostate cancer should not use it. If you’re scheduled for surgery, stop taking it beforehand, as it may affect sedation and blood pressure during the procedure.
Putting It Together
A practical starting protocol looks like this: choose a root extract standardized to at least 2.5 to 5% withanolides, begin at 300 mg per day with food, and take it at whatever time of day matches your goal. After a week, you can increase to 600 mg if needed, either as a single dose or split into two. Plan to use it for 8 to 12 weeks, then take a 2 to 4 week break to reassess. Keep an eye on how you feel in the first few days, especially any stomach discomfort or unusual drowsiness, and adjust your timing or dose accordingly.