Herbalism (‘herbology’ or ‘herbal medicine’) is the use of plants for medicinal purposes, and the study of such use. It covers all sorts of medicinal plants, natural remedies or cures, traditional and alternative medicines. Modern medicine tends to categorise herbalism firmly as an ‘alternative therapy’ as its practice is not strictly based on evidence gathered using the scientific method. Modern medicine does make use of many plant-derived compounds however, as the basis for evidence-tested pharmaceutical drugs. Phytotherapy also works to apply modern standards of effectiveness testing to medicines derived from natural sources.

Medicinal plants have been identified and used throughout human history. Archaeological evidence indicates that the use of medicinal plants dates at least to the Paleolithic age, approximately 60,000 years ago. Written evidence of herbal remedies dates back over 5,000 years to the Sumeranians, who created long lists of useful plants. A number of ancient cultures wrote on plants and their medical uses. In ancient Egypt, herbs are mentioned in Egyptian medical papyri, depicted in tomb illustrations, or on rare occasions found in medical jars containing trace amounts of herbs. The earliest known Greek ‘herbals’ were those of Diocles of Carystus, written during the third century BC, and one by Krateuas from the first century BC. Only a few fragments of these works have survived intact, but from what remains scholars have noted that there is a large amount of overlap with the Egyptian herbals.