The inhalation route of administration is probably still the most popular way to use medical cannabis. The fast onset of effects after a single inhalation makes it easy and intuitive for patients to titrate small doses over a short time and adequately treat their symptoms.This also makes inhalation the preferred route for treating acute symptoms. Vape cartridges and concentrates are becoming more popular but flower is the choice of many patients today.


Combustion, that is burning the cannabis and inhaling the smoke produced is the most commonly used inhalation technique. Smoking cannabis is simple for most patients and the apparatus required is low cost. Smoking does have some issues which limit its usefulness. It is not very discreet, producing significant environmental smoke and odor. Smoking is not very efficient with up to 70% of cannabinoids and terpenes being lost through the process. The smoke can be irritating to the throat and lungs, causing coughing. This is a particular problem for patients with asthma and COPD, as the coughing can irritate the airways, worsening the symptoms. These patients will often find vape cartridges and concentrates no better. Fortunately, there is an alternative.

Dry Herb Vaporization

The other inhalation technique which uses flower is Dry Herb Vaporization (DHV). In this case the flower is not burned. It is heated to the point that the cannabinoids and terpenes boil from the flower (the heat applied also decarboxylates the cannabinoids) in a vapor form. Only the vapor is inhaled. It retains all of the benefits of the inhalation route of flower administration but with more efficiency, in a more discreet fashion which is much less irritating to the airways.

Dry herb vaporizers are electronic devices with an oven chamber into which a small amount of flower is placed. The oven is heated to the temperature at which the cannabinoids and terpenes will vaporize (180C – 185C typically) and the vapor produced is inhaled. There are of course disadvantages. The quality DHV devices are not inexpensive, they do require a charged battery or household current to operate, they require occasional cleaning/maintenance and there is a learning curve in becoming proficient.


Any patient who requires or prefers the inhalation route should consider DHV. They are more efficient, discreet and cause less coughing. Patients who have had issues with combustion causing coughing should consider trying DHV with a high pinene chemovar to open up those airways.