What is the TD50 (Median Toxic Dose) of Ashwagandha?

From the Research

The TD50 for ashwagandha is not well-established in humans, but based on available research, ashwagandha appears to have a good safety profile at typical therapeutic doses of 300-600 mg daily of root extract. The most recent and highest quality study on the safety of ashwagandha root extract was conducted in 2021 1, which found no statistically significant change or abnormality in hematological and biochemical parameters, including thyroid hormonal profile, in healthy adults taking 300 mg of ashwagandha root extract twice daily for 8 weeks.

Key Findings

• Acute toxicity studies in animals suggest the LD50 is relatively high, with values reported between 1,000-1,750 mg/kg in rodents, indicating a wide therapeutic window 1.
• For human use, doses up to 1,000 mg daily of standardized root extract have been used in clinical trials without serious adverse effects, though mild side effects like gastrointestinal discomfort, drowsiness, and headache may occur 2, 3, 4.
• The safety margin appears substantial, but individual sensitivity varies, and those with autoimmune conditions, thyroid disorders, or taking medications should exercise caution as ashwagandha may interact with certain drugs and affect thyroid hormone levels 1, 2, 3, 4.
• Pregnant and breastfeeding women should avoid ashwagandha due to insufficient safety data 1, 2, 3, 4.

Recommendations

• Always start with lower doses and consult a healthcare provider before beginning supplementation 1, 2, 3, 4.
• Be aware of the variability in ashwagandha products and quality controls, as well as the reported evidence regarding use, safety profile, and clinical implications in stress reduction 5.