The most standard method of cannabis application is through inhalation-either by cigarette, pipe, or vaporizer. These methods are most preferred by patients due to the immediate effects they impart after inhalation, making it easier to adjust dosage as needed or with preference. The effects will also be stronger immediately, offering much faster relief from such symptoms as pain and nausea.
Unfortunately a person is still ingesting smoke no matter the method of inhalation they choose, and it is possible for this smoke to be noxious. To date, however, all studies and research have failed to link inhalation of marijuana (even over extended periods of time) to the typical negative pulmonary effects of tobacco smoking. In fact, moderate cannabis smoking (or smoking at least one joint per day for seven years or one joint per week for 49 years) was shown to be completely unrelated to any negative pulmonary function by a study conducted in 2012 by the Journal of American Medical Association (JAMA). Inhalation has also been shown to lack association with increased prevalence of various strains of cancer such as melanoma or breast cancer and no relation to tobacco-associated cancers such as lung cancer. The largest case-controlled study ever to investigate the respiratory effects of cannabis inhalation, held in 2006, confirmed the lack of association between marijuana and lung-related cancers, even in subjects who had reported smoking over 22,000 joints in their lifetimes. The study was initially hypothesized to show a positive link between lung cancer and marijuana use, but actually showed the reverse, even hinting at evidence of a protective effect on the user.
In the pipe variation of ingesting cannabis, especially in the water-pipe filtration system, the cannabis smoke is cooled to a comfortable level for the throat and lungs but unfortunately is ineffective at eliminating the toxic combustion byproducts. Because of this, many cannabis user choose to utilize a vaporizer instead, whose technology heats the plant enough to form cannabinoid vapors, but not enough for combustion. This allows consumers to experience the immediate effects of smoking while still avoiding the coughing and wheezing typical of smokers. Vaporization has been proven in multiple clinical studies to be a safe and effective delivery system for marijuana while also boasting a higher plasma concentration of THC than smoking.
Another method of cannabis medication and consumption is oral ingestion through foods or tinctures. These methods offer a much different and possibly more intense effects than inhalation, but the outcome is not felt until at least 45 minutes after ingestion. The dosage is therefore much more difficult to determine not only because of this delayed effect but also because orally consumed cannabinoids are typically much stronger and have longer-lasting effects than through inhalation. This more powerful result is mainly caused by how differently the human body metabolizes alternate forms of THC. Inhaled THC passes immediately from the lungs to the bloodstream and brain, but a large amount of THC ingested orally is changed into metabolite 11-hydroxy-THC before it enters the brain, which is considered more potent than standard THC and induces magnified physical and psychoactive effects due to a greater blood-brain penetrability.