Ashwagandha for Stress and Anxiety: Does It Actually Work?
Ashwagandha (Withania somnifera) has been used in Ayurvedic medicine for centuries, but its status in modern nutrition science is something unusual: it's an ancient herb with solid contemporary clinical trial data. The evidence for its effects on stress and anxiety is stronger than for most supplements in this category.
What Ashwagandha Is
Ashwagandha is classified as an adaptogen — a category of herbs that are thought to help the body adapt to physical and psychological stress. The active compounds, called withanolides, appear to modulate the HPA axis (hypothalamic-pituitary-adrenal axis), which is the central stress response system that governs cortisol production.
What the Research Shows
Multiple double-blind, placebo-controlled trials have found significant reductions in self-reported stress and anxiety with ashwagandha supplementation. A well-cited 2012 study found 300mg twice daily reduced stress scores by 44% and serum cortisol by 27.9% compared to placebo over 60 days. More recent trials using standardised extracts have shown similar results, with effects typically becoming noticeable after 4-8 weeks.
The effect on sleep quality has also been studied — several trials show improvements in sleep onset and quality, likely mediated by the cortisol-lowering effect.
What to Look For When Buying
Not all ashwagandha products are equal. Look for:
- KSM-66 or Sensoril — the two most studied standardised extracts, both used in clinical trials
- Standardised for withanolides — typically 5% or higher
- Third-party tested for heavy metals (ashwagandha can accumulate metals from soil)
- Avoid products without standardisation information — the withanolide content in unstandardised powder is highly variable
Dosage and Timing
Clinical trials typically use 300-600mg of standardised extract per day. Some use twice-daily dosing (morning and evening), others once daily. Most people take it with food to reduce the chance of mild stomach upset. Effects are gradual — expect 4-8 weeks before assessing whether it's working.
It can be taken long-term — most trials run 8-12 weeks with no concerning side effects in healthy adults.
Who Should Be Cautious
Ashwagandha is generally well tolerated, but avoid or consult a doctor if you have thyroid conditions (it may affect thyroid hormones), autoimmune disease, are pregnant, or take immunosuppressants or thyroid medications.
Our Stress Relief meal plan includes supplement recommendations alongside foods known to support healthy cortisol levels. Ashwagandha pairs well with a diet structured around reducing the physiological stress load.
Get the Stress Relief Meal Plan →Consult a healthcare provider before taking ashwagandha if you have thyroid conditions, autoimmune disease, or are pregnant.