Ashwagandha Side Effects
Ashwagandha is generally well-tolerated with minimal side effects in healthy adults at standard doses (300-600 mg daily), though it carries sedative properties that can potentiate anesthesia, and rare but serious neurological complications including acute dystonia have been reported. 1, 2, 3
Common and Mild Side Effects
The most frequently reported adverse effects are mild and include:
- Gastrointestinal discomfort - This is the most common complaint across dietary supplements including ashwagandha 1
- Sedation and drowsiness - Ashwagandha has independent sedative properties that can cause daytime sleepiness 1
- No serious adverse events were reported in an 8-week safety trial of 80 healthy adults taking 300 mg twice daily 2
- No abnormalities in vital signs, hematological parameters, liver enzymes, or thyroid function were observed in controlled trials 2, 4
Serious and Rare Adverse Effects
Neurological Complications
- Acute-onset dystonia has been documented following ashwagandha supplementation, presenting as sustained involuntary muscle contractions and abnormal posturing that resolved upon discontinuation 3
- This represents a rare but clinically significant adverse effect requiring immediate recognition and cessation of the supplement 3
Perioperative Risks
- Enhanced sedation during anesthesia - Ashwagandha has sedative properties independent of anesthesia and can alter the safety profile of prescribed anesthetic medications through pharmacokinetic interactions 1
- Cytochrome P-450 interactions - Many anesthetic agents are metabolized via CYP450 pathways, and ashwagandha may attenuate or enhance sedative properties of anesthetics 1
- Perioperative cessation is recommended for supplements with sedative properties to avoid unpredictable interactions with anesthesia 1
Theoretical Risks Requiring Monitoring
Hypotension
- While not directly documented for ashwagandha, dietary supplements can cause unintended hypotensive effects 1
- Monitor blood pressure in patients taking ashwagandha, particularly those on antihypertensive medications 1
Hypoglycemia
- Dietary supplements used in diabetes management can cause hypoglycemia 1
- Exercise caution in patients with diabetes or those taking glucose-lowering medications 1
Clinical Considerations and Monitoring
When prescribing or counseling patients about ashwagandha:
- Start with standard doses (300 mg once or twice daily) that have been studied in clinical trials 2, 4, 5
- Assess for sedation particularly in the first 2-4 weeks of use 4, 5
- Discontinue before surgery due to sedative properties and potential anesthetic interactions 1
- Monitor for dystonia or other movement disorders, though rare 3
- Counsel patients to report any neurological symptoms immediately 3
Safety Profile Summary
- Short-term use (8-12 weeks) at doses of 300-600 mg daily appears safe based on controlled trials 2, 4, 5, 6
- No hepatotoxicity was observed in safety studies, unlike some other botanical supplements 2
- No thyroid dysfunction was detected in controlled trials 2
- Mild adverse effects are comparable to placebo in most studies 2, 4, 5
Important Caveats
- Long-term safety data beyond 12 weeks is limited and requires further investigation 2
- Lack of FDA regulation means product quality, purity, and actual withanolide content varies significantly between manufacturers 1
- Drug interactions beyond anesthetics are not well-characterized and warrant caution 1
- Pregnancy and lactation safety has not been established 2