Alchemy has been practiced in ancient Egypt, Mesopotamia (modern Iraq), India, Persia (modern Iran), China, Japan, Korea, the classical Greco-Roman world, the medieval Islamic world, and then medieval Europe up to the 20th century, in a complex network of schools and philosophical systems spanning at least 2,500 years.

Although these were not the only uses for the discipline, they were the ones most documented and well-known. Certain Hermetic schools argue that the transmutation of lead into gold is analogical for the transmutation of the physical body.

Alchemists contributed distillation to Western Europe. The double origin of Alchemy in Greek philosophy as well as in Egyptian and Mesopotamian technology set, from the start, a double approach: the technological, operative one, which Marie-Louise von Franz call extravert, and the mystic, contemplative, psychological one, which von Franz names as introvert.

The word alchemy derives from the Old French alquimie, which is from the Medieval Latin alchimia, and which is in turn from the Arabic al-kimia (الكيمياء). This term itself is derived from the Ancient Greek chemeia (χημεία).