Herbal supplements are "safe" and "harmless," and UK use is rising. Some natural remedies are dangerous. Ethnic cures sometimes include heavy metals, Western medications, and banned animals and plants. Certain plants interact with prescription medicines and harm the liver or kidneys. Patients whose symptoms may be related to herbal products might benefit from the clinical laboratory's assistance in learning about the effects of herbal products on laboratory tests and receiving recommendations for further study. Physicians must take a medication and herbal history.