Allopathic medicine is an expression commonly used by homeopaths and proponents of other forms of alternative medicine to refer to mainstream medical use of pharmacologically active agents or physical interventions to treat or suppress symptoms or pathophysiologic processes of diseases or conditions. The expression was coined in 1810 by the creator of homeopathy, Samuel Hahnemann (1755–1843). Never accepted as a mainstream scientific term, it was adopted by alternative medicine advocates to refer pejoratively to mainstream medicine. In such circles, the expression “allopathic medicine” is still used to refer to “the broad category of medical practice that is sometimes called Western medicine, biomedicine, evidence-based medicine, or modern medicine”.

The practice of medicine in both Europe and North America during the early 19th century is sometimes referred to as heroic medicine because of the extreme measures (such as bloodletting) sometimes employed in an effort to treat diseases. The term allopath was used by Hahnemann and other early homeopaths to highlight the difference they perceived between homeopathy and the medicine of that time. With the term allopathy (meaning “other than the disease”), Hahnemann intended to point out how physicians with conventional training employed therapeutic approaches that, in his view, merely treated symptoms and failed to address the disharmony produced by the underlying disease.

Homeopaths saw such symptomatic treatments as “opposites treating opposites” and believed these conventional methods were harmful to patients. Practitioners of alternative medicine have used the term “allopathic medicine” to refer to the practice of conventional medicine in both Europe and the United States since the 19th century. The term allopathic was used throughout the 19th century as a derogatory term for the practitioners of heroic medicine, a precursor to modern medicine that did not rely on evidence.