Ashwagandha: dose, KSM-66 vs Sensoril, timing, and who should skip it
Quick answer
Most ashwagandha trials use a standardized root extract at a specific dose — so the branded extract and the milligrams matter more than the brand. The honest buyer's guide, plus who shouldn't take it.
Alex Soto, Founder, VitaminDB
6 min readUpdated 6/28/2026 NIH-sourced
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Ashwagandha is the most popular adaptogen on the shelf, and the research is more specific than the marketing — which is good news, because it tells you exactly what to look for.
The dose and the extract are what matter
Almost every meaningful ashwagandha study uses a standardized root extract at a defined dose — not raw powder. So two numbers decide whether a product matches the evidence:
- Is it a standardized extract (with a stated withanolide percentage or a named branded extract)?
- Is the dose in the studied range — commonly 300–600 mg/day?
A "1,000 mg ashwagandha root powder" capsule with no standardization is not the same as 600 mg of a standardized extract, even though the bigger number looks more impressive.
KSM-66 vs Sensoril
The two branded extracts you'll see most:
- KSM-66 — a root-only extract, typically dosed around 300–600 mg/day. It's the extract behind much of the stress, sleep, and strength/resistance-training research.
- Sensoril — a root-and-leaf extract standardized to a higher withanolide content, used at lower doses (~125–250 mg), often positioned more for stress/relaxation.
Neither is categorically superior. Pick the extract whose studied dose and use-case match what you want, then check the milligrams are in range.
Timing
There's no hard rule. Many people take it in the evening for the calming/sleep angle; others split it morning and night. Take it consistently with food — the effects build over weeks, not from a single dose.
How to buy without overpaying
Because the effective dose is well-defined, ashwagandha is a clean cost-per-dose comparison: find a standardized extract (KSM-66 or Sensoril) at 300–600 mg, then compare what a real daily dose costs — not the bottle. Current picks are on the ashwagandha hub; we rank by cost per effective dose (methodology).
Who should skip it
This is the part the ads omit. Be cautious or avoid if you are pregnant, have a thyroid condition or take thyroid medication (ashwagandha can raise thyroid hormone levels), have an autoimmune condition, take sedatives, or have liver concerns (rare reports of liver injury exist). When in doubt, ask a clinician.
Bottom line
Buy a standardized extract (KSM-66 root-only or Sensoril root-and-leaf), dose it in the 300–600 mg research range, take it consistently — and skip it entirely if you're pregnant, on thyroid meds, or in the other caution groups above.
Covered nutrients: ashwagandha
See the live cost-per-dose data
This guide is editorial — the prices below are real and current.
Frequently asked questions
KSM-66 or Sensoril — which is better?
They're two standardized extracts studied at different doses. KSM-66 is a root-only extract typically used around 300–600 mg/day and is the one most associated with stress and strength studies. Sensoril is a root-and-leaf extract standardized to more withanolides, used at lower doses (~125–250 mg). Neither is universally "better" — match the form to the dose used in the research you care about.
How much ashwagandha per day?
Trials commonly use 300–600 mg/day of a standardized extract. More isn't clearly better. That's a general research reference, not medical advice.
Who should avoid it?
People who are pregnant, have thyroid conditions or take thyroid meds (it can raise thyroid hormones), have autoimmune conditions, or take sedatives — and anyone with liver concerns (rare liver-injury reports exist). Clear it with a clinician if any apply.
Deals on these nutrients
Now Foods, Ashwagandha, 450 mg, 180 Veg Caps
Cost per serving
$0.12
180 servings · ~180-day supply
Saffron Supplements with Ashwagandha & L-Theanine - 368.5MG…
Cost per serving
$0.17
90 servings · ~90-day supply
Saffron Gummies Supplements with 88.5 mg Saffron Extract
Cost per serving
$0.05
120 servings · ~120-day supply
Nature's Truth, Ashwagandha Root Quick Release, 920 Mg, 90…
Cost per serving
$0.12
90 servings · ~90-day supply
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