An herb is a plant or plant part used for its scent, flavor, or therapeutic properties. Herbal medicines are one type of dietary supplement. They are sold as tablets, capsules, powders, teas, extracts, and fresh or dried plants. People use herbal medicines to try to maintain or improve their health.

About 100 years ago, natural herbs were the main remedy for treating human diseases. It has been estimated that 25% of modern medicines are made from plants first used traditionally [1], such as aspirin, artemisinin, ephedrine, and paclitaxel. However, there is limited scientific evidence to establish the safety and efficacy of most herbal products [2]. With the wide application of chemical drugs, herbal medicine and other traditional therapies have shown sharp contraction.

As a country with rich herbal resource, China is not an exception. In recent decades, spectrum of disease has shifted and the complex chronic diseases have become the main part. The effect of Western medicine treatment is not satisfactory and problems of the adverse drug reaction are also very prominent. The complementary and alternative treatment, especially the herbal medicine, has gained more attention and has also become popular.