The buds of the flowering tops of the female of the Cannabis indica species of hemp, considered as a drug. (The buds of some C. sativa strains may also be considered marijuana; however, they are much less potent.) Marijuana has been used as a medicine and a recreational drug throughout human history. Its medical uses and cultural importance are discussed elsewhere in this node (and other nodes); this writeup discusses the technology of its use.

The pharmacologically active ingredients of marijuana are tetrahydrocannabinol (THC) as well as various cannabinoids. To be of use, these chemicals must be unbound from the cells of the plant. (Eating marijuana raw is not very effective, as the human digestive system cannot break down the plant's cell walls.) Most marijuana users do this by smoking the buds; however, THC can also be extracted through vaporization, cooking in oil, or by dissolving it out in alcohol. THC is also present in hashish, the resin of the marijuana buds, which is not discussed below.

Smoking: Marijuana is usually smoked in cigarettes, pipes, or water pipes. When smoked in cigarettes, it may be mixed with tobacco; this "joining" of two herbs gives rise to the term "joint", which is still used even though this mixing is rare nowadays. Pipes for marijuana smoking take many forms, but tend to be compact in size. Unlike tobacco pipes, which are designed to preserve and improve the flavor of the smoke, marijuana pipes are designed for concealment or to intensify the "hit" of smoke. Some pipes, known as stash pipes, have a chamber in the stem which may be also filled with marijuana. As the smoke passes over the stored herb, THC-bearing resin is deposited in it, making it more powerful.

Water pipes deserve special notice. All water pipes cool the smoke by bubbling it through water. (Other fluids are rarely used. The use of alcoholic beverages in a water pipe is counterproductive, as THC dissolves in alcohol; see below.) There are two major varieties of water pipe -- the bong or bhong, which has a single fixed cylindrical mouthpiece; and the hookah, which may have several mouthpieces on hoses, for multiple smokers. The design of some bongs and hookahs is quite elaborate, and in some cases quite decorative as well.

Marijuana smokers have also been known to improvise smoking implements when no proper one is available. Marijuana may be smoked out of a cored-out apple, an empty soda can with holes punched in it, or any number of similar kludges.

Vaporization: The most recently devised way to consume marijuana is to volatilize the active ingredients out from it without burning. This may be done with electric heating devices which resemble bongs or hookahs, or with special pipes similar to crack pipes. Vaporization may be more healthful than smoking, since it avoids the production of tar, carbon monoxide, and other smoke constituents.

Cooking: When marijuana is added to oily or fatty foods and cooked, the THC dissolves into the oil. Some marijuana eaters use the more fragrant varieties of the plant as a spice, particularly on pizza or other foods where oregano might be used. It has also been baked into cookies, fried in butter which is then used in other foodstuffs, and melted into cheese. When cooking with marijuana, more THC will be extracted if one grinds the herb finely first; this increases the surface area accessible to the oil.

Dissolving: THC is insoluble in water, but very soluble in ethanol. It may thus be extracted by steeping the plant in vodka or any other relatively neutral spirit. Enterprising users have found this a useful way to extract THC from the stems and leaves, which are not preferred for smoking: by steeping the otherwise useless plant parts in vodka for a matter of weeks, they produce a beverage which causes the drinker to become both stoned and drunk. Extraction into oil or other solvents is also practical, and is used in the preparation of Marinol.