Plants have been used for medicinal purposes for as long as history has been recorded. There is evidence from the Sharnidar Cave in Iraq that suggests Neanderthals living 60,000 years ago used medicinal plants. A body that was unearthed there had been buried with eight species of plants which are still widely used in folk medicine around the world (Medicinal plants in a Middle Paleolithic grave ShanidarIV?, Lietava J., J Ethnopharmacol. 1992 Jan;35(3):263-6., PMID 1548898).
Many of the pharmaceuticals currently available to physicians have a long history of use as herbal remedies, including opium, aspirin, digitalis and quinine. In fact, at least 7,000 of medical compounds in the modern medicine are derived from plants sources (Summary Report for the European Union, 2000-2005, QLK5-CT-2000-00111). The majority of these medicinal plants came to the attention of researchers because of their use in traditional medicine (Summary Report for the European Union, 2000-2005, QLK5-CT-2000-00111).