Can ashwagandha (Withania somnifera) cause heart palpitations (tachycardia)?

Ashwagandha and Heart Palpitations

Yes, ashwagandha can cause heart palpitations and tachycardia in some individuals, particularly through its effects on thyroid function and autonomic nervous system. 1

Mechanism of Action

Ashwagandha (Withania somnifera) can potentially cause heart palpitations through several mechanisms:

1. Thyroid Stimulation: Ashwagandha has been documented to cause thyrotoxicosis, which can present with supraventricular tachycardia 1. This herb may increase thyroid hormone levels, particularly thyroxine (T4), which can lead to tachycardia and palpitations.

2. Autonomic Nervous System Effects: Ashwagandha has been shown to affect heart rate variability 2, suggesting it impacts the autonomic nervous system which controls heart rhythm.

3. Cardioactive Properties: Research indicates ashwagandha has cardiotropic and cardioprotective properties 3, which while potentially beneficial in some contexts, may alter cardiac function in others.

Clinical Evidence

The most compelling evidence comes from a case report of a 73-year-old female who developed supraventricular tachycardia and symptoms of hyperthyroidism after two years of using ashwagandha root extract as a self-administered treatment for hypothyroidism 1. Her symptoms resolved completely after discontinuation of the supplement.

While some studies suggest ashwagandha may have beneficial cardiovascular effects, including potential reduction in systolic blood pressure when combined with other herbs 4, the risk of tachycardia and palpitations cannot be ignored.

Risk Factors and Monitoring

Individuals at higher risk for experiencing palpitations with ashwagandha include:

• Those with pre-existing thyroid disorders, particularly subclinical hypothyroidism
• Patients with known cardiac arrhythmias
• Individuals taking medications that affect heart rate
• Those with anxiety disorders (as palpitations may worsen anxiety symptoms)

Management of Ashwagandha-Induced Palpitations

If palpitations occur while taking ashwagandha:

1. Discontinue Use: Immediate cessation of ashwagandha is recommended 1
2. Medical Evaluation: A 12-lead ECG should be obtained to assess for arrhythmias 5, 6
3. Thyroid Function Testing: Check thyroid function to rule out thyrotoxicosis 6
4. Cardiac Monitoring: Consider 24-hour Holter monitoring if symptoms persist 6

Prevention and Recommendations

For individuals considering ashwagandha use:

• Pre-existing Cardiac Conditions: Those with known arrhythmias, structural heart disease, or cardiovascular disease should avoid ashwagandha or use with extreme caution
• Medication Interactions: Be aware that ashwagandha may interact with cardiac medications and thyroid medications
• Dosage Considerations: Start with lower doses and monitor for symptoms
• Regular Monitoring: Those on long-term ashwagandha should have periodic assessment of thyroid function and cardiovascular parameters

Safety Profile

While ashwagandha is generally considered safe for short-term use in many studies 7, the potential for cardiovascular side effects exists. Common adverse effects reported include:

• Somnolence and drowsiness
• Gastrointestinal discomfort
• Mild and transient side effects in most cases

However, the case report of supraventricular tachycardia 1 highlights that more serious cardiovascular effects can occur, particularly with long-term use or in susceptible individuals.

In conclusion, while ashwagandha has many purported benefits, its potential to cause heart palpitations through thyroid stimulation and direct cardiac effects warrants caution, particularly in those with pre-existing cardiac or thyroid conditions.