Even single herbs should be used with caution, or best left to the experts to match them to an individual's chemistry. For instance, kelp, in addition to containing appreciable amounts of iodine and bromine, raises potassium and sodium, while alfalfa also raises potassium, but lowers sodium. Most people are aware now that licorice, by raising sodium and depleting potassium, could be bad news for patients who retain too much sodium, or suffer from kidney-related disorders. Milk thistle, if used by the wrong patient, could induce iron-deficiency anemia, devil's claw taken over time could worsen hepatitis, cirrhosis, or migraines, while Kava Kava could cause congestive liver disease... Full Text