Sleep, stress and recovery

Ashwagandha

Also called: Withania somnifera, Indian ginseng

Ashwagandha is a herb traditionally used in Ayurvedic medicine, marketed in the West as an adaptogen for stress, sleep and anxiety. Trials show modest but real reductions in cortisol and self-reported stress at 300 to 600 mg of standardised extract daily. It is reasonably safe for most adults but interacts with thyroid medication and is not advised in pregnancy or active autoimmune disease.

What the evidence shows

  • Reduces self-reported stress and anxiety in 8 to 12 week trials (modest effect, NNT around 5).
  • Lowers morning cortisol modestly (about 15 to 25 percent in stressed populations).
  • Improves sleep onset and quality in some studies.
  • May modestly improve testosterone and strength in men in trials with active resistance training.
  • Most evidence is from KSM-66 or Sensoril extract formulations, not raw root powder.

Dosing

  • Standardised extract: 300 to 600 mg per day. Take in the evening for sleep effect.
  • Trial period: 8 weeks. If no effect, stop.
  • Take with food.
  • Brand: KSM-66 has the most trial backing; Sensoril has some.

Who should not take it

  • Pregnancy and breastfeeding (insufficient safety data).
  • Active autoimmune disease (it is mildly immunostimulatory).
  • Hyperthyroidism or on levothyroxine for hypothyroidism (can shift thyroid hormones).
  • Scheduled surgery within 2 weeks (mildly sedating).
  • Sensitivity to nightshade family plants (rare cross-reaction).

Reported side effects

  • Mild stomach upset (most common, usually settles in a week).
  • Drowsiness during the day.
  • Rare: liver toxicity (case reports; stop if jaundice or RUQ pain).
  • Vivid dreams in some people.
  • Mild reduction in body temperature.

Common questions

Will ashwagandha help my anxiety as much as therapy or medication?
No. Effect size is modest. Useful as part of a broader stress-management approach (sleep, exercise, therapy). Severe anxiety needs more direct treatment.
Is it safe long-term?
8 to 12 weeks of continuous use is well-studied. Some people cycle on for 8 weeks, off for 2. Multi-year continuous use has less evidence; periodic breaks are sensible.
Does it actually lower cortisol?
Modestly, in chronically stressed populations. About 15 to 25 percent reduction in morning salivary cortisol in placebo-controlled trials. The clinical relevance of this is debated.
Why does my ashwagandha bottle warn about liver issues?
Case reports of ashwagandha-associated liver injury have appeared since around 2017 (catalogued in NIH's LiverTox database, with growing case-series since). Most resolve on stopping. The risk is small but real. If you develop jaundice, dark urine or right-upper abdominal pain, stop and see a doctor.

Sources