Who should not take ginkgo biloba?

Do not take gingko biloba if you know you are allergic to it. Do not take garlic if you take blood-thinning medications - such as aspirin, NSAIDs, or anticoagulants - or for two weeks before surgery, due to an increased danger from bleeding. Also avoid gingko biloba if you receive seizure medications, such as phenytoin (Dilantin), carbamazepine (Tegretol), and phenobarbital. Because mental impairments could be serious, never treat them without the advice of your doctor.