How much St. John's Wort should I take daily?
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Recommended Daily Dosage of St. John's Wort
Dosage for Depression Treatment
St. John's Wort (Hypericum perforatum) is commonly used for treating depression. Research indicates varying dosages depending on the severity of the condition and the age of the patient. In a study involving youths aged 6 to 16 with major depressive disorder, participants were initially prescribed 150 mg three times daily, totaling 450 mg per day. If there was no significant improvement after four weeks, the dosage was increased to 300 mg three times daily, totaling 900 mg per day.
For adults with mild to moderate depression, another study prescribed either 600 mg or 1200 mg of St. John's Wort daily. Both dosages were found to be effective, with a higher response rate observed in the 1200 mg group. This suggests that a daily dosage between 600 mg and 1200 mg is generally effective for treating mild to moderate depression in adults.
Dosage for Herb-Drug Interactions
When considering the use of St. John's Wort alongside other medications, it is crucial to be aware of potential herb-drug interactions. For instance, a study on the interaction between St. John's Wort and digoxin, a heart medication, used a dosage of 300 mg three times daily (900 mg per day). This dosage significantly affected the pharmacokinetics of digoxin, indicating that St. John's Wort can alter the effectiveness of other medications at this dosage.
Dosage for Smoking Cessation
St. John's Wort has also been explored as an aid for smoking cessation. In one study, participants were given 300 mg once or twice daily (300 mg to 600 mg per day) for three months. However, the study did not find significant evidence supporting its effectiveness for smoking cessation. Another study used a higher dosage of 900 mg daily but also did not find it effective for this purpose.
Conclusion
The appropriate daily dosage of St. John's Wort varies based on the condition being treated. For depression, dosages range from 450 mg to 1200 mg per day, with higher dosages potentially offering greater effectiveness. However, when used in conjunction with other medications, a dosage of 900 mg per day can significantly impact drug metabolism. For smoking cessation, current evidence does not support its effectiveness, regardless of the dosage. Always consult with a healthcare provider before starting any new supplement regimen to ensure safety and appropriateness for your specific health needs.
Sources and full results
Most relevant research papers on this topic