Yes. Some herbal products can cause major problems during surgery. We are learning more about these products as they become more widely used. St. John’s wort and gingko biloboa are two herbal products that can definitely cause major problems with blood pressure during surgery. Because herbal products are sold over-the-counter and are largely unregulated, it is difficult for us to know their dosage. We expect you to discontinue all herbal products two weeks before surgery, unless otherwise directed by your surgeon.