Neidan is the Taoist term for internal alchemy, a practice of cultivating spiritual transformation within the body.
The word neidan literally means “inner elixir” or “internal alchemy.” Taoist practitioners developed it as an inward counterpart to waidan, or external alchemy, which used substances and laboratory-like methods in attempts to produce an elixir of longevity.
Neidan practices commonly use symbolic language drawn from alchemy, cosmology, and traditional Chinese medicine. They may describe refining essence, energy, and spirit, often through meditation, breath regulation, visualization, and moral cultivation. The goal varies among traditions, but commonly involves spiritual transformation, longevity, or union with the Tao.
Neidan should not be treated as the same thing as qigong. Qigong is a broader category of exercises involving breath, movement, and energy, while neidan refers specifically to an internal-alchemical framework within Taoist practice.