Ashwagandha dosage safety
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Ashwagandha Dosage Safety in Animal Studies
Animal studies have shown that ashwagandha root extract is safe at high doses. In repeated-dose toxicity studies, rats given up to 2000 mg/kg body weight per day for 90 days showed no adverse effects, with no observed toxicity in clinical signs, blood tests, or organ health 13. Similarly, sub-acute toxicity studies in rats using doses up to 800 mg/kg body weight per day for 28 days found no major abnormalities or signs of intoxication 6. Whole-plant extracts were also found safe up to 1000 mg/kg/day in rats over 28 days 5.
Ashwagandha Dosage Safety in Human Clinical Trials
Human clinical trials have tested ashwagandha root extract at various dosages and durations. In healthy adults, taking 300 mg twice daily (600 mg/day) for 8 weeks did not cause any significant changes in blood tests, liver function, thyroid function, or vital signs, and no adverse events were reported 2. Another study in patients with insomnia and anxiety used the same dose (300 mg twice daily) for 10 weeks and found the supplement was well tolerated, with no significant side effects 8. In subclinical hypothyroid patients, 600 mg daily for 8 weeks was also found to be safe, with only mild and temporary adverse effects reported in a small number of participants 7.
A study using a lower dose of 120 mg once daily for 6 weeks in healthy adults also reported no treatment-related adverse events, with all safety parameters remaining within normal limits 10.
Mutagenicity and Genotoxicity Safety
Ashwagandha root extract did not show any mutagenic or genotoxic effects in laboratory tests, even at high concentrations. Acute oral toxicity studies in animals found no mortality or morbidity up to 2000 mg/kg, further supporting its safety profile 3.
Sustained-Release Formulations and Safety
A pharmacokinetic study comparing sustained-release and standard ashwagandha capsules (each 300 mg) in healthy men found no adverse events with single doses, suggesting that both formulations are well tolerated 4.
Review of Safety and Toxicity Data
Comprehensive reviews of ashwagandha’s pharmacological and safety data confirm that the herb is generally safe at recommended dosages, with a low risk of toxicity or serious side effects in both preclinical and clinical settings 9.
Conclusion
Current evidence from animal and human studies indicates that ashwagandha root extract is safe at commonly used dosages (up to 600 mg/day in humans and up to 2000 mg/kg/day in animals) for periods up to 10 weeks. No significant adverse effects, toxicity, or mutagenic risks have been observed at these levels. However, long-term safety and effects at higher dosages require further research.
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