How can cannabis be taken as a medication?

Here, we show general ways in which medical cannabis products can be administered. These instructions can be used for reference after your medical consultation, but do not replace your doctor’s instructions, which always take precedence over these general instructions. Always contact your doctor if you experience severe adverse reactions.

Please note that the effects of your medicine may not be felt immediately but might develop over time or with adjustments of the dose; this is done in collaboration with the doctor.

The handling and intake of your medical cannabis product depends on the route of administration.

Inhalation

A fast onset of action can be obtained by inhaling cannabis. Cannabis can be inhaled through either smoking or vaporisation. Smoking cannabis involves burning the flowers (600-900°C) and inhaling the active components with the smoke. This is not recommended, as some combustion products are carcinogenic and can harm the lungs. Instead, vaporisation is the recommended path of inhalation, as the plant material is not burnt. Rather, it is heated at a lower temperature, with the active ingredients in the plant released as steam that the patient can inhale1.

Medical cannabis products in 'flower' ('flos') form should ideally be inhaled using a vaporiser licenced as medical device2.

Using a vaporiser

  1. 1We always recommend that you follow your doctor’s instructions, which can be supported by the written instructions issued by the manufacturer of the vaporiser.

  2. 2Unprocessed flower should be ground before use to improve dosage consistency. A herb grinder can be used for this purpose.

  3. 3Store products as recommended. If possible, it may be helpful to store the unprocessed flowers in the refrigerator or freezer, as this makes grinding easier2. Pharmacies can prepare ground flowers as indicated in your prescription.

  4. 4Ground flower is placed in a heating chamber (maximum capacity defined by manufacturer), which is then inserted into the vaporiser.

  5. 5The chamber is heated to 160-230°C (your doctor will advise you on the exact temperature) to decarboxylate and vaporise the cannabinoids2. The exact temperature can usually be set on the device.

  6. 6Inhale the steam and hold your breath for approximately 5 seconds for optimal absorption of the cannabinoids into the bloodstream through the lung alveoli. Note that the steam can irritate the respiratory tract and cause coughing.

  7. 7Once there is no steam visible when exhaling, the material in the vaporisation chamber is considered used up.

  8. 8The device should be cleaned and stored according to manufacturer instructions after each use.
Whole and ground cannabis flower

Whole and ground cannabis flower.

Oral

Medical cannabis to be taken orally is available in tincture (alcohol-based solution), oil or capsule form.

Patients who use medical cannabis to treat chronic pain often prefer oral ingestion because of the long-lasting effect, so they will not have to consume the medication as often. The long onset of action might mean that it takes longer to find the right dose, however. This needs to be considered when adjusting the dose2.

Using oils

  1. 1It is recommended to dispense the oil (gently shake the sealed vial before use) onto a teaspoon by holding the dropper or pipette vertically over the spoon for accurate dosing. Please note that droplet sizes may change when switching to another dripping device. The oil may be viscous, which results in slow dripping.

  2. 2After dosing, you may insert the spoon into your mouth and swallow the oil.

Cannabis oil

Hold the dropper vertically over the spoon for accurate dosing.

Preparation of tea

Cannabis tea offers a way to ingest cannabis flowers orally. Please note that because the solubility of THC and CBD in water is low, there is a risk of wasting some of the cannabinoids, as they are not released from the flowers. The risk of inconsistent dosing and incomplete decarboxylation (conversion of cannabinoids into neutral forms) are other factors to bear in mind when considering tea as a route of administration3.

  1. 1Grind the plant material to homogenise it and dose it as advised by your doctor. Grinding may increase the dosing consistency.

  2. 2Add boiling water and cover with a lid to prevent evaporation of the terpenes.

  3. 3After 15 minutes of boiling, strain out the solid plant parts using a strainer or a sieve3.

  4. 4The tea may taste a little harsh, depending on the medical cannabis cultivar used. You can improve the taste by adding honey, milk, or flavoured tea.

  5. 5The shelf life and solubility of the cannabinoids increase when milk, cream or other fatty compounds are added3.

Oromucosal

Cannabis can be administered as oromucosal products, such as oromucosal sprays and sublingual extracts. In these products, some of the cannabinoids are absorbed directly from the mouth into the bloodstream via the mucosal barrier, and another portion of the cannabinoids is washed by the saliva flow into the gastrointestinal tract and absorbed there.

Using sublingual extracts

Sublingual means ‘under the tongue’. The product typically comes in a glass bottle with a dripping device or a pipette for accurate dosing.

  1. 1It is recommended to dispense the oil (gently shake the sealed vial before use) onto a teaspoon by holding the dripping device or pipette vertically over the spoon for accurate dosing. Please note that droplet sizes may change when switching to another dripping device. The oil may be viscous, which can result in slow dripping.

  2. 2After dosing, you can insert the spoon into your mouth under your tongue and remove it slowly.

  3. 3Waiting a few minutes before swallowing might increase the absorption of cannabinoids across the mucosal barrier.

Using oromucosal sprays

  1. 1It is recommended to hold the spray between your thumb and middle finger. Your index finger is placed on the nozzle.

  2. 2You need to prime the pump and check for functionality the first time you use the spray. This is done by holding the spray upright and spraying into a tissue a couple of times until a fine mist appears.

  3. 3The spray is now ready to use and should be held upright when pointing the nozzle under your tongue or towards the inside of your cheek.

  4. 4Press the nozzle down firmly to dose accurately.

Oromucosal administration of cannabis

Oromucosal administration of cannabis.

Please contact your doctor or pharmacy with any questions about how to administer your medical cannabis.



References

1. Grotenhermen & Häußermann. Verordnungshilfe für Ärzte. (2017).

2. MacCallum, C. A. & Russo, E. B. Practical considerations in medical cannabis administration and dosing. European Journal of Internal Medicine vol. 49 12–19 (2018).

3. Hazekamp, A., Bastola, K., Rashidi, H., Bender, J. & Verpoorte, R. Cannabis tea revisited: A systematic evaluation of the cannabinoid composition of cannabis tea. Journal of Ethnopharmacology 113, 85–90 (2007).