Most clinical trials on ashwagandha use standardized root extracts in doses ranging from 200 to 600 mg per day, taken as one or two capsules. The specifics of how you take it, when you take it, and which extract you choose all affect your experience. Here’s what the evidence supports.
Dosage by Extract Type
Ashwagandha supplements are not all the same. Different brands use different patented extracts, each standardized to contain a specific concentration of withanolides, the active compounds responsible for the plant’s effects. The amount you take depends on which extract you’re using.
KSM-66 is one of the most widely studied root extracts, standardized to more than 5% withanolides per 300 mg capsule. It’s been tested for sleep quality, anxiety, and mental alertness. A typical dose is 300 to 600 mg daily.
Sensoril uses both root and leaf, delivering a higher withanolide concentration at lower milligram amounts. Doses in studies typically range from 125 to 250 mg.
Shoden is a highly concentrated root and leaf extract, with 21 mg of withanolide glycosides packed into just a 60 mg capsule. It’s been studied primarily for sleep, including time to fall asleep and total sleep duration.
If you’re using a generic or store-brand ashwagandha, check the label for withanolide content. Products standardized to at least 2.5% to 5% withanolides tend to align with what’s been used in clinical research. Raw root powder, sold in bulk, requires higher amounts (often 1,000 mg or more) because it’s far less concentrated.
When to Take It
There is no universally agreed-upon best time of day. Some clinical trials had participants take ashwagandha in the evening after dinner, while others split the dose into morning and night. If your primary goal is better sleep, taking it in the evening makes intuitive sense. If you’re using it for daytime stress or focus, a morning dose is reasonable. Many people take it with a meal to reduce the chance of stomach discomfort, which is the most common side effect at higher doses.
The honest answer is that you may need to experiment. Try one timing for a couple of weeks, then adjust if it’s not working or if you notice drowsiness at an inconvenient time.
How Long Before You Notice Results
Ashwagandha is not something you feel on the first day. Most people notice a difference after four to twelve weeks of consistent daily use. The effects tend to be subtle at first: you may realize you’re sleeping more soundly, or that your baseline stress feels slightly lower. Experts in integrative medicine generally recommend committing to at least three months before deciding whether it’s working for you.
Capsules, Powder, or Liquid
Capsules are the most popular format for good reason. They’re pre-dosed, tasteless, and easy to travel with. The main downside is a slightly higher price compared to bulk powder.
Powder is cheaper and can be mixed into smoothies, tea, or coffee, but ashwagandha has a bitter, earthy taste that many people find unpleasant. Measuring accurate doses with a spoon is also trickier than swallowing a capsule with a known milligram count.
Liquid extracts are more concentrated, so you take smaller volumes, but they’re typically the most expensive option and still carry that strong taste. For most people, capsules with a standardized extract offer the best balance of convenience, consistency, and cost.
Cycling On and Off
Taking ashwagandha continuously for months without breaks raises some concerns. Chronic use can potentially affect thyroid hormone levels and other hormonal pathways. A common cycling approach is two weeks on, two weeks off. This pattern helps reduce the risk of liver stress or hormonal disruption while still allowing the supplement to do its work during “on” periods. If you prefer a gentler approach, some people take it five days a week with weekends off, though this is based more on practical caution than clinical trials.
Side Effects and Liver Risk
At normal doses, ashwagandha is generally well tolerated. The most common complaints are nausea, vomiting, and digestive upset, especially at higher doses or on an empty stomach.
A more serious concern involves the liver. Over 70 case reports in the medical literature have linked ashwagandha to liver injury, ranging from mildly elevated liver enzymes to jaundice and, in rare cases, acute liver failure requiring a transplant. The NIH classifies ashwagandha as a grade B liver toxicity risk, meaning it is a likely cause of clinically apparent liver injury in some people. Hepatologists at CU Anschutz Medical Campus have noted seeing patients with liver damage where ashwagandha was the only identifiable risk factor.
This doesn’t mean ashwagandha will harm your liver. Most users experience no issues. But if you notice yellowing of your skin or eyes, dark urine, or unusual fatigue, stop taking it and get your liver enzymes checked.
Who Should Avoid Ashwagandha
Ashwagandha is not recommended for people with autoimmune disorders or thyroid conditions. It can stimulate the immune system and alter thyroid hormone levels, which could worsen conditions like Hashimoto’s thyroiditis, lupus, or rheumatoid arthritis. People scheduled for surgery should also stop taking it beforehand, as it may interact with anesthesia and other perioperative medications.
Ashwagandha can interact with several types of medication:
- Thyroid medications: it may raise thyroid hormone levels, throwing off your prescribed dose
- Diabetes medications: it can lower blood sugar, increasing the risk of hypoglycemia
- Blood pressure medications: it may amplify their effects
- Sedatives and anti-seizure medications: combined sedative effects could become excessive
- Immunosuppressants: ashwagandha may counteract drugs designed to suppress immune activity
Pregnant and breastfeeding women are typically advised to avoid ashwagandha due to insufficient safety data.
A Practical Starting Plan
If you’re trying ashwagandha for the first time, start with a standardized root extract (KSM-66 is the most studied) at 300 mg once daily, taken with food. After a week with no stomach issues, you can increase to 600 mg daily, split into two doses or taken at once. Take it in the evening if sleep is your priority, or in the morning for stress and focus. Plan to cycle off for at least two weeks after every two to four weeks of use, and give it a full eight to twelve weeks before evaluating whether it’s making a meaningful difference.