Literally "extracting the essence," this type of ritual has as its goal the extraction of the potency or "essence" (bcud) from substances (such as flowers, mercury, the elements, and so forth), generally with the goal of using that substance for nourishment, to increase one's lifespan, or to strengthen one's body. Such practices are especially popular with hermits who have only limited access to ordinary food.

The category of "alchemy" is very broad, and can refer to practices that simply transform substances (such as transforming iron into gold); in addition, it can refer to practices where a yogi subsists on extracted esences, and to sexual practices that involve extracting energetic potencies from a consort.