Adaptogens

Ashwagandha — timing, dose & interactions

Ayurvedic adaptogen studied for stress, anxiety and sleep in short trials. Can raise thyroid hormone levels; rare cases of liver injury are reported.

Also known as Withania somnifera, KSM-66, Sensoril

Timing

When to take it

Evening is common for sleep and stress; take with food if it upsets your stomach.

Interactions

Ashwagandha with other supplements

Safety

Medications & health conditions

CautionThyroid hormone

Ashwagandha may raise thyroid hormone levels. Ashwagandha has increased T3/T4 in some studies. Combined with thyroid medication, this could push levels too high — get your levels checked.

Human data
NoteBlood pressure medication

Ashwagandha may lower blood pressure. Possible additive effect with blood pressure medication.

Mechanism-based
CautionDiabetes medication

Ashwagandha may lower blood sugar. Additive glucose-lowering could increase hypoglycemia risk with insulin or sulfonylureas. Monitor glucose.

Human data
CautionSedatives or sleep medication

Ashwagandha may add to sedation. Combining with benzodiazepines or other sedatives may increase drowsiness.

Human data
CautionImmunosuppressants

Ashwagandha may stimulate the immune system. It could counteract immunosuppressive drugs. Avoid unless your doctor approves.

Mechanism-based
CriticalPregnant or breastfeeding

Avoid ashwagandha during pregnancy. Ashwagandha may have abortifacient effects and is not recommended in pregnancy or while breastfeeding.

Human data
CriticalLiver disease

Ashwagandha has been linked to liver injury. Case series describe cholestatic liver injury, sometimes severe. Avoid with existing liver disease.

Human data
CautionHyperthyroidism or autoimmune thyroid disease

Ashwagandha may raise thyroid hormone levels. Avoid with hyperthyroidism; use caution with autoimmune thyroid disease.

Human data
CautionSurgery in the next 2 weeks

Stop ashwagandha before surgery. May add to the effects of anesthesia and sedatives — pause 2 weeks before.

Mechanism-based

Buying guide

What to look for on the label

  • Ashwagandha

    • Standardized root extract (KSM-66 or Sensoril)

FAQ

Common questions

When is the best time to take Ashwagandha?

Bedtime. Evening is common for sleep and stress; take with food if it upsets your stomach.

Should Ashwagandha be taken with food?

It can be taken with or without food. Evening is common for sleep and stress; take with food if it upsets your stomach.

Can you take Ashwagandha with L-Theanine?

Yes — just be aware the calming effects may add up, especially at night. Start one at a time. Avoid combining with alcohol or sleep medications without advice.

Sources

References

  1. 01NIH Office of Dietary Supplements — Ashwagandha Fact Sheet for Health Professionals
  2. 02Philips CA et al. Ashwagandha-induced liver injury — a case series from India and literature review. Hepatol Commun 2023.