Both are standardized, well-studied extracts. KSM-66 is a root-only extract often used for stress and strength; Sensoril includes leaf and is higher in withanolides, sometimes favored for calm and sleep. Either is a reasonable, tested choice.

Many people use it in cycles (weeks on, then a break) rather than continuously, partly because long-term safety data are limited. There's no strict rule, but cycling is a common, cautious approach.

Can I take it with thyroid medication?

Be careful — ashwagandha can raise thyroid hormone levels, which may interact with thyroid conditions or medication. Check with your provider first.

Ashwagandha: Benefits, Dosing & Evidence

What it is

Ashwagandha is a root used in Ayurvedic tradition and classed as an adaptogen — an herb thought to help the body cope with stress. Standardized extracts (such as KSM-66 and Sensoril) are the forms most studied.

How it works

Ashwagandha is classed as an adaptogen — a plant thought to help the body regulate its stress response. Its active compounds (withanolides) appear to modulate the HPA axis, the hormonal system that governs cortisol, your main stress hormone. In trials it's associated with lower perceived stress and reduced cortisol, along with effects on calming, GABA-related pathways.

What it's been studied for

Taken to support stress resilience, a calmer mood, and sleep, and sometimes for exercise recovery.

What the evidence shows

A meta-analysis of randomized trials found ashwagandha reduced measures of stress and anxiety compared with placebo — one of the better-supported stress botanicals, though trials are relatively short.

Who should consider it

It's most used by people dealing with everyday stress, feeling 'wired but tired,' or wanting steadier mood and sleep; some athletes use it for recovery. It is not a treatment for diagnosed anxiety or depression — those deserve professional care. It's generally aimed at otherwise-healthy adults under ordinary stress.

Amounts commonly studied

Studies commonly use 300-600 mg per day of a standardized root extract.

How to take it

Studies commonly use 300-600 mg per day of a root extract standardized to withanolides (KSM-66 and Sensoril are the researched brands). It can be taken once or split, and some take it in the evening for sleep. It's typically used in cycles — for example a few weeks to a couple of months — rather than indefinitely. Take it with food if it bothers your stomach.

Forms & absorption

Look for a standardized extract (KSM-66 or Sensoril) with the withanolide content stated, rather than raw powder of unknown potency.

Food sources

None — ashwagandha (Withania somnifera) is a medicinal root, not a dietary food. It's taken only as a supplement, tea, or traditional preparation.

Safety & interactions

Generally well tolerated short-term. It isn't recommended in pregnancy, and people with thyroid conditions or on thyroid medication should use it only with guidance, since it may affect thyroid hormone. Rare reports of liver issues exist.

Myths & what it won't do

Myth: ashwagandha meaningfully boosts testosterone in most men. Reality: a few small studies show modest changes, mainly in specific groups; it isn't a reliable testosterone booster. Myth: natural means risk-free. Reality: it can raise thyroid hormone levels, isn't advised in pregnancy, and rare cases of liver injury have been reported — so it isn't for everyone.

Common questions

KSM-66 or Sensoril?: Both are standardized, well-studied extracts. KSM-66 is a root-only extract often used for stress and strength; Sensoril includes leaf and is higher in withanolides, sometimes favored for calm and sleep. Either is a reasonable, tested choice.
Should I cycle it?: Many people use it in cycles (weeks on, then a break) rather than continuously, partly because long-term safety data are limited. There's no strict rule, but cycling is a common, cautious approach.
Can I take it with thyroid medication?: Be careful — ashwagandha can raise thyroid hormone levels, which may interact with thyroid conditions or medication. Check with your provider first.

The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.

Ashwagandha