June 2014

St. John's Wort Commonly Mixed with Medications

St. John's wort is commonly taken with drugs that might cause dangerous interactions, according to a new study.

Extracts of Hypericum perforatum L. (St. John's wort) have been recommended traditionally for a wide range of medical conditions. The most common modern-day use of St. John's wort is for depression. Studies have shown St. John's wort may be equally effective as tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitor (SSRI) antidepressants for mild to moderate depression. St. John's wort may cause serious interactions with prescription drugs, herbs, or supplements. Therefore, people using any medications  should consult their healthcare providers, including a pharmacist, prior to starting therapy.

In a recent study, researchers analyzed data from the National Ambulatory Medical Care Survey, including patients who were prescribed to take St. John’s wort between 1993 and 2010. The authors reviewed which medications were also prescribed with St. John’s wort.

The researchers found that 28% of the people taking St. John’s wort also took a drug with the potential to cause a serious interaction. Some of these drugs included selective serotonin reuptake inhibitor (SSRI), benzodiazepines, warfarin, birth control pills, statins, verapamil, and digoxin.

The authors concluded that physicians should be aware of the potentially dangerous interactions associated with St. John’s wort and warn their patients before use.

For more information about St. John’s wort, please visit Natural Standard’s Foods, Herbs & Supplements Database.


  1. Davis SA, Feldman SR, Taylor SL. Use of St. John's Wort in Potentially Dangerous Combinations. J Altern Complement Med. 2014 Jun 23. 
  2. Natural Standard: The Authority on Integrative Medicine.

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