There are several routes of delivery available for patients to safely and effectively consume their medical cannabis. The amount of cannabinoids such as THC received by the patient depends on the route of administration taken.

Combustion

Combustion can be in a variety of forms, such as a pipe, water bong or rolled cannabis joint. It is generally not recommended as smoking can contribute to COPD and produces undesirable compounds that can be irritating to the lungs.

• Up to 30% of the active ingredients are lost in sidestream smoke and combustion
• Effects are usually felt within 30 to 60 seconds and fully develop within 10 to 15 minutes
• Effects typically last between 2 to 3 hours

Vaporization

A vaporizer is a device that heats the dried cannabis matter without causing combustion, producing a vapour rich in cannabinoids that can be inhaled directly. Several models of vaporizers are available and can be chosen based on the preferences of the patient.

• Much more efficient than smoking as there is no loss of cannabinoids due to pyrolysis
• Effects are usually felt within 30 to 60 seconds and fully develop within 10 to 15 minutes
• Effects typically last between 2 to 3 hours
• Does not produce undesirable compounds that can cause lung irritation

Edible Items

Whereas effects occur within minutes when smoking or vaporizing marijuana, these effects have a slower onset and a longer duration in the case of oral ingestion. For orally administered cannabinoids, data shows that a maximum of 20% of the administered dose enters the systemic circulation, indicating extensive first-pass metabolism. Hence, this requires much larger amounts of dried marijuana to be used when preparing orally ingestible items to achieve comparable effects to vaporizing or smoking.

Note that when ingested orally, THC is primarily metabolized to 11-hydroxy-THC, a metabolite that can be 3 to 4 times more potent and result in a much more intense effect as compared to smoking or vaporizing. This makes it essential to manage oral doses carefully, with a rule of thumb being beginning with half or a quarter of a piece of an edible containing 1 gram of marijuana and waiting at least 60 minutes before ingesting higher amounts of edible items.