Ashwagandha: dose, KSM-66 vs Sensoril, timing, and who should skip it

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:

1. Is it a standardized extract (with a stated withanolide percentage or a named branded extract)?
2. 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. Two things come straight from NCCIH: there is not enough information to draw conclusions about ashwagandha's long-term safety, and although it is rare, a number of cases have linked liver injury to ashwagandha supplements. 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.