Most ashwagandha studies use between 300 and 600 mg per day of a standardized root extract, and that range is a solid starting point for most people. But the right dose for you depends on what type of extract you’re taking, since different products concentrate the active compounds at very different levels. Understanding those differences is the key to getting the dose right.
Why the Type of Extract Matters More Than the Number
Ashwagandha’s effects come from compounds called withanolides. A raw root powder contains a relatively small percentage of these compounds, so you need a larger dose. A concentrated extract packs more withanolides into a smaller capsule. Clinical trials have used anywhere from 120 mg to 1,250 mg per day of extract, or up to 6,000 mg of root powder, and those aren’t interchangeable numbers. A 600 mg dose of one product can deliver a completely different amount of active compounds than 600 mg of another.
Three branded extracts dominate the market, and each has its own concentration and dose range:
- KSM-66: Standardized to 5% withanolides. The most widely studied form, typically dosed at 300 mg twice daily (600 mg total). This is the extract behind the majority of published research.
- Sensoril: Standardized to 10% withanolides (made from both root and leaf). Effective doses start as low as 125 mg for stress-related benefits and go up to 500 mg for strength and physical performance.
- Shoden: Standardized to 35% withanolides, meaning it works at much lower doses. Studies have used 60 mg for hormonal effects, 120 mg for sleep (producing a 42% increase in restorative sleep in one trial), and 240 mg for stress response.
If your supplement label doesn’t specify which extract it uses, look for the withanolide percentage. A product standardized to 5% withanolides will need roughly six times the dose of one standardized to 35%.
Doses Used for Stress and Anxiety
Most people searching for ashwagandha are looking for help with stress. The adaptogenic effects, meaning ashwagandha’s ability to help your body regulate its stress response, show up consistently in the 300 to 600 mg per day range of a root extract. One study found significant reductions in stress and anxiety after just six to eight weeks at these doses. The mechanism involves lowering cortisol, the hormone your body produces under stress, and modulating the signaling system that connects your brain to your adrenal glands.
If you’re using Sensoril, you can start at the lower end (125 mg) and see if that’s enough. For KSM-66, 300 mg twice a day is the most replicated protocol in the research.
Doses Used for Sleep
Ashwagandha can improve sleep quality, but it takes longer to kick in than most people expect. Some reviews suggest you need at least six to eight weeks of consistent use to notice meaningful changes, and studies lasting beyond eight weeks tend to show stronger sleep improvements than shorter ones. Drowsiness is actually listed as a common side effect, which in this case works in your favor.
For sleep specifically, 120 mg of Shoden taken daily improved restorative sleep in a six-week trial. With KSM-66 or a standard root extract, 300 to 600 mg daily is the typical range. Taking your dose after dinner or before bed makes practical sense if sleep is your primary goal, though no study has rigorously compared morning versus evening timing.
Doses Used for Exercise and Testosterone
Ashwagandha has a surprisingly solid evidence base for physical performance. In studies of both trained athletes and untrained adults, doses from 120 to 1,250 mg per day over two to eight weeks improved aerobic capacity, exercise recovery, and physical strength. For testosterone, studies showing increases in levels and sexual function used higher doses, ranging from 600 to 5,000 mg per day over 8 to 12 weeks.
If you’re taking ashwagandha for gym performance, 600 mg of a standard root extract is a reasonable middle ground. Sensoril at 500 mg has also been studied specifically for strength. Higher doses (above 1,000 mg) have been used, but with less certainty around long-term safety.
Take It With Food
Ashwagandha can cause mild stomach discomfort when taken on an empty stomach. Taking it with a meal, a snack, or blended into a smoothie helps avoid nausea and loose stools. There’s no strong evidence that taking it with fat specifically improves absorption, but eating something alongside it is a simple way to reduce the most common side effects.
You can split your dose (for example, 300 mg in the morning and 300 mg in the evening) or take it all at once. If you’re using it for sleep, evening dosing makes sense. For stress or exercise, the timing is less important than consistency.
How Long You Can Safely Take It
Ashwagandha is considered safe for up to three months of continuous use at 300 to 600 mg per day. Beyond that, the safety data gets thin. Most clinical trials last 8 to 12 weeks, and the NIH notes that long-term safety is simply not well established.
This is not a trivial concern. Liver injury has been reported in a small number of people taking 450 to 1,350 mg daily for periods ranging from one week to four months. Some of those individuals had pre-existing liver conditions, but not all. Symptoms included jaundice, nausea, fatigue, and abdominal discomfort. There have also been three case reports of thyroid overactivity in women taking ashwagandha, one involving an unusually high dose of 1,950 mg per day for more than two months.
Because of these reports, many practitioners suggest cycling: using ashwagandha for two to three months, then taking a break for a few weeks before starting again. There’s no formal clinical guideline for cycling, but it’s a reasonable precaution given the limited long-term data.
Who Should Avoid Ashwagandha
The NIH recommends against ashwagandha for people with autoimmune disorders, thyroid conditions, or upcoming surgery. Because it can influence thyroid hormone levels, it may interfere with thyroid medications. It also appears to raise testosterone, so men with hormone-sensitive prostate cancer should not take it.
Ashwagandha can interact with medications for anxiety and thyroid function. One of the reported liver injury cases involved a young man combining ashwagandha with multiple anti-anxiety drugs, making it hard to pin down ashwagandha as the sole cause but raising a real flag about drug interactions. If you take prescription medications, especially for thyroid, mood, or liver-related conditions, this is worth a conversation with your prescriber before starting.