Adverse reactions to St John's Wort

Objective: To report 2 cases of adverse reactions to St John's wort, a popular herbal treatment for depression. Method: We present 2 case histories and review the existing literature regarding St John's wort. Results: St John's wort may cause serotonin syndrome in sensitive patients. In addition, St John's wort may be associated with hair loss. Conclusions: For clinical reasons, it is important to recognize and report adverse reactions to herbal remedies and to document that these treatments have side effects commensurate with their potent action on brain neurochemistry.