Herbal medicine is one of the oldest forms of healthcare, second only to hands on medicine. Every culture has developed a relationship with the plants and herbs indigenous to their geographic location. Chinese Herbal medicine is unique because it is a compendium of herbal medicine from nearly every climate zone on the planet. In China the study of herbs and their medicinal uses has advanced over time from singe herb use to the use of herbal formulas and complex combinations. Most of the pharmacopoeia of Western Bio-medicine in the 20th century was developed primarily by isolating active chemical compounds from native plants and herbs, then synthetically reproducing them for mass distribution and uniformity of concentration. Herbal medicine continues to influence the medicines of today. Many prescription drugs in the United States have at least one active ingredient that comes from plant extracts or synthesized plant compounds.