Want to learn about medical cannabis?

Example of the location of CB1 (blue) and CB2 (green) receptors of the endocannabinoid system throughout the body.

An Introduction to the
Endocannabinoid System

Endocannabinoids are natural chemical messengers that are produced by the body and interact with cannabinoid receptors and proteins within our endocannabinoid system (ECS).5,9 Cannabinoid receptors are found throughout the body including the central and peripheral nervous system, cardiovascular system, liver, kidney, gastrointestinal tract, reproductive system and in the skin.9 The balance, or homeostasis, of our ECS is maintained through interactions between the cannabinoid receptors and endocannabinoids.10 In particular, the ECS helps regulate multiple processes in the body.9,10

Example of the location of CB1 (blue) and CB2 (green) receptors of the endocannabinoid system throughout the body.

Three Major Cannabinoids

Endocannabinoids (Body)
Anandamide (AEA) 2-Araquinodilglicerol (2-AG)
Phytocannabinoids (Plant)
Cannabidiol (CBD) Tetrahydrocannabinol (THC) Cannabichromene (CBC) Cannabigerol (CBG) Epidiolex Nabiximols
Synthetic Cannabinoids
Dronabinol Nabilone

There are three major categories of cannabinoids that can interact with our bodies’ ECS.5,12 These include endocannabinoids that are produced by our own body, phytocannbinoids that are produced by plants and synthetic cannabinoids that are made through chemical synthesis.12,15-17 All of these forms of cannabinoids can interact with the ECS and can have an effect in our body.

Information About Medical Cannabis

Brief History of Cannabis
Regulatory Framework for Medical Cannabis in Canada
Medical Cannabis Use in Canada
Types of Medical Cannabis Products
Importance of Working with a Healthcare Practitioner
Dosage & Titration
Warnings & Precautions

Brief History of Cannabis

Example of various cannabis delivery forms including inhalables, orals and topicals.

Cannabis has been used as medical treatment for millennia by many cultures with innumerable historical anecdotes of success for a wide variety of conditions. About 80 years ago, cannabis as a treatment suffered a major setback when it was deemed of no medicinal value by the World Health Organization (WHO).1 Additionally, in 1971 the United States declared a war on drugs, ostensibly to eradicate the drug trade and drug use. As part of this campaign, cannabis was grouped with cocaine and other more addictive substances as a Schedule 1 drug in the Controlled Substances Act.1 As a consequence, it became difficult to conduct research on the potential of cannabis or its derivatives as medical treatments.

Despite this, in the ensuing years, studies were performed using whole plant extracts, cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC) isolates as treatments.2,3 Unfortunately, most of these studies were limited by several methodological problems including being underpowered, poorly designed, and inadequately blinded. However, since those early studies, ongoing clinical trials have demonstrated significant progress and generated evidence and with the evolving regulatory landscape it is now possible to conduct methodologically sound trials.4 More recently a 2017 review of cannabidiol by the World Health Organization (WHO) concluded that CBD does not appear to have abuse potential or cause harm, therefore recommending that CBD should no longer be internationally scheduled as a controlled substance.1, 23

Regulatory Framework for
Medical Cannabis in Canada

There are three major categories of cannabinoids that can interact with our bodies’ ECS.5,12 These include endocannabinoids that are produced by our own body, phytocannbinoids that are produced by plants and synthetic cannabinoids that are made through chemical synthesis.12,15-17 All of these forms of cannabinoids can interact with the ECS and can have an effect in our body.

Brief overview of recent major milestones related to Canadian medical cannabis regulations.

A survey completed by the Canadian Pharmacists Association found that 61% of medical cannabis users are currently self-medicating.8

Medical Cannabis Use in Canada

Currently, there are over 350,000 patients registered to use cannabis for medical purposes.7 Yet, the Canadian Pharmacists Association reported that 61% of medical cannabis users are self medicating without the guidance of healthcare practitioners (HCP).8 Prior to January 2020, the medical products available for patients were extremely limited, with product offerings consisting mainly of dried flower and basic oil drops. However, novel delivery forms and more advanced formulations can provide patients with other options. Indeed, over 75% of patients prefer smokeless and non-inhalation product alternatives for medical use.8


Phytocannabinoids are found in many plants, but the highest concentrations are found in cannabis. There are over 100 known phytocannabinoids produced in the cannabis plant that have been shown to interact with the ECS.11 Interestingly, individual cannabinoids have different potential benefits and side effect profiles.13,15,26 Often cannabinoids are consumed together and with the presence of terpenes.25 Together, the effect of these ingredients in a formulation may cause an entourage effect, or a synergistic effect.26-32

The most well-known phytocannabinoids are Tetrahydrocannabinol (THC) and Cannabidiol (CBD).12 THC, a partial agonist of the CB1 receptor, is known for its psychoactive effect or “high” sensation that alters mood or mental state. In contrast, CBD, a negative allosteric modulator of the CB1 receptor is non-psychoactive, meaning it does not produce a “high” feeling. More recently, other cannabinoids such as cannabigerol (CBG) have been identified for their potential therapeutic benefits.18-21 The potential interactions of CBG with the endocannabinoid system and beyond could provide additional benefits.18-21

Types of Medical Cannabis Products

Advances in medical cannabis have led to the creation of various type of products that provide smoke-free options while maintaining the plant derived nature of medical cannabis. There currently are various options including sublingual sprays, oil drops, capsules, topical creams and gels. These products provide better dose control, consistency, quality and are safer than smokable product options. Finally, HCP can help you select products to meet your specific symptom management needs. For example, if you require instant relief your HCP may provide you with a faster acting sublingual spray, whereas if you require longer relief you may be prescribed an oral drop or capsule that acts for a longer duration.

Properties of various medical cannabis delivery forms.4, 11, 18

Importance of Working with
a Healthcare Practitioner

Like any other prescription medication, medical cannabis products must be taken in consultation with a HCP. When determining whether medical cannabis products are appropriate for you to use, the HCP considers factors such as: age, history of psychiatric conditions, cardiovascular or cerebrovascular conditions, liver and kidney disease; pregnancy/ breastfeeding or planning to become pregnant; or a history of drug or substance disorder.5,22

Your HCP should also help to guide you with the following:

  • Product selection: determining the type of delivery method that is most appropriate for your treatment plan.  If your HCP doesn’t feel comfortable with helping decide which products you should take then you can seek support from our cannabis care team.
  • Titration: help you find the right dose to limit unwanted side effects while maximizing benefit.
  • Evaluate current medications: HCP will help identify whether any current or non-prescription drugs can result in potential negative interactions when taken together with medical cannabis.
  • Identify a Treatment Plan: HCP will assess the severity of specific conditions and indications, aid in the monitoring of treatment, and develop a plan to discontinue treatment should an adverse effect occur.

Patients should consult their practitioners about the following considerations when defining personalized medical cannabis regimens:

The various factors that HCP must consider when developing a treatment plan for patients.

Note: It is particularly important to take into consideration any other medications being used by the patient for any potential interaction with cannabis.

What do I need to do to get a medical document or authorization for medical cannabis?

Like any other prescription medication, medical cannabis products must be taken in consultation with a HCP. When determining whether medical cannabis products are appropriate for you to use, the HCP considers factors such as: age, history of psychiatric conditions, cardiovascular or cerebrovascular conditions, liver and kidney disease; pregnancy/ breastfeeding or planning to become pregnant; or a history of drug or substance disorder.5,22

Questions to ask your HCP

These are some examples of questions you can ask your HCP when they are providing a medical authorization form for you. If your HCP does not have the answer then you can call the MyMedi.ca Call Centre at 1-844-500-2040. Alternatively, if your HCP does not feel comfortable prescribing medical cannabis you can speak to a certified health care provider that is listed on our website.

  1. Do you have other patients for whom you have prescribed medical cannabis as a treatment?
  2. Will I experience any side effects when taking medical cannabis?
  3. Are you able to recommend a specific product, or will you help me
    find the right product to manage my particular symptoms?
  4. What type of product is best to address my needs?
  5. How much medical cannabis should I take?
  6. Will you help me adjust my dosage level if needed?
  7. What time of day should I take medical cannabis?
  8. How long does it take until I begin to feel any benefits?
  9. What are the therapeutic effects and how long do they last?
  10. How will this affect my everyday activities?
  11. How long will my authorization last?

Treatment Plan

Your HCP provider will be important in determining your treatment plan. HCP use a start low and go-slow approach to help determine an appropriate treatment dosing, while minimizing any side effects.22 As everyone’s response may be different, it is important to keep track of any side effects that you may experience. If you experience any serious adverse effects then you should immediately discontinue use and contact your HCP.

Dosage & Titration

In the absence of guidelines, it is recommended that patients take a “start low and go slow” approach in order to understand how their body reacts to cannabis. To achieve this, titration methods are used to find the right dose by which patients experience therapeutic effects with no or minimal adverse effects.

Guide to Start Low and Go Slow recommendations for prescribing medical cannabis.22

As everyone’s response to medical cannabis may be different, patients should start with a low dose and discontinue use if they experience any adverse effects. However, the period of observation may be shorter or longer depending on the formulation and delivery method. Use of cannabinoids should be both effect and product specific.

If you do not experience the desired therapeutic effect(s) after a predetermined period, patients may, depending on the individual context, try an alternative delivery form, or it may be recommended by their prescriber that use by the patient be discontinued.

Potential Side Effects of Medical Cannabis Use

Side effects associated with cannabis-based medicines, in particular with products containing high levels of THC.5, 22
Each product may cause different types of side effects to occur. Products that contain high amounts of THC are more commonly associated with a higher risk of side effects. If you experience serious adverse side effects and/or psychoactive effects, it is recommended to discontinue use of the product and immediately contact your HCP.5, 22

Warnings & Precautions

In addition to precautions taken with titration and dosing, your HCP would typically consider the following general contraindications that have been set forth by Health Canada before prescribing medical cannabis:5
  • Patients under the age of 25 years old
  • Previous history of psychiatric conditions including schizophrenia, bipolar disorder
    and psychosis
  • Severe hepatic or renal, cardiovascular or cerebrovascular disease putting you at
    a greater risk for hypertension, tachycardia, and stroke
  • Pregnant, trying to become pregnant, or breastfeeding;
  • and/or a history of drug or substance disorder
  • Co-administration of medical cannabis products (high in THC) with central nervous
    system depressants (i.e., alcohol, barbiturates, and benzodiazepines).4
  • Co-administration with stimulants such as cocaine, MDMA, and amphetamines can
    lead to increased risk of tachycardia.
  • Medical cannabis use may lead to dependence, tolerance, and withdrawal symptoms
    following heavy or frequent use.5


Travelling outside of Canada with medical cannabis is illegal. For more information on international travel while carrying medical cannabis, please visit travel.gc.ca. If you are travelling with medical cannabis within Canada, be prepared to show your medical documentation. Your documentation and the amount of cannabis you carry must be in accordance with the Access to Cannabis for Medical Purposes Regulations.

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