Herbal medicine. What is the evidence?

This is the final in the series of 13 articles looking at current herbal therapy. It reviews those plants with clinical and scientific evaluation sufficient to consider adoption into orthodox medicine. Surprisingly some commonly used herbs, such as the purple coneflower (Echinacea purpura), valerian and ginseng, do not as yet pass the test, but others such as St John's wort, ginkgo, saw palmetto now have sufficient clinical studies to consider orthodox use. With the huge interest in herbal treatment it is likely that other plants will join the list following adequate clinical evaluation.