Ashwagandha
Ashwagandha (Withania somnifera) is an adaptogenic herb used in Ayurvedic medicine for over 3000 years. It helps the body manage stress, can lower cortisol, and supports sleep, energy, and cognitive function.
What is Ashwagandha?
Ashwagandha (Withania somnifera), also called Indian ginseng or winter cherry, is one of the most used herbs in Ayurvedic medicine. It is classified as an adaptogen — a substance that helps the body adapt to physical and mental stress.
How does ashwagandha work?
The active compounds in ashwagandha are called withanolides. These act through several mechanisms:
- HPA axis — Ashwagandha modulates the hypothalamic-pituitary-adrenal axis, which controls the body's stress response. This can lower cortisol levels.
- GABA receptors — Withanolides can bind to GABA receptors in the brain, producing a calming effect and potentially improving sleep.
- Thyroid function — Ashwagandha may stimulate the thyroid and support the production of T3 and T4.
- Antioxidant — Protects cells from oxidative stress and free radicals.
Scientifically proven benefits
Stress reduction and cortisol
Several double-blind, placebo-controlled studies show that ashwagandha can reduce cortisol levels by 11-32%. In one study with 60 participants taking 300 mg ashwagandha extract (KSM-66) twice daily for 60 days, cortisol levels decreased significantly compared to the placebo group.
Sleep
Ashwagandha has been shown to improve sleep quality. A 2021 meta-analysis confirmed that ashwagandha enhances sleep, with the strongest effect in individuals with sleep problems (insomnia).
Physical performance
Studies indicate that ashwagandha can increase muscle strength, VO2 max, and recovery after exercise. One study showed a 17% greater increase in testosterone levels and 18% greater muscle growth compared to placebo.
Cognitive function
Ashwagandha may improve attention, memory, and reaction time. The effect is believed to be due to antioxidant protection of brain cells and modulation of neurotransmitters.
Dosage
- Stress reduction: 300-600 mg standardized extract (KSM-66 or Sensoril) per day
- Sleep: 300-600 mg, taken in the evening
- Physical performance: 300-600 mg per day
- Root powder: 1-6 g per day (lower concentration of withanolides)
Side effects and precautions
Ashwagandha is generally well tolerated. Possible side effects include mild gastrointestinal discomfort, diarrhoea, and drowsiness. It should be avoided by pregnant women, individuals with autoimmune diseases, and those taking thyroid medication without medical consultation.