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Beginner’s Guide to Cannabis

Learn about medical cannabis, how it works, and what it can do for you.

About cannabis

What is cannabis?

The term “cannabis” covers a range of medicinal and recreational products made from the plant, cannabis sativa. While it has a number of different names (e.g. pot, marijuana, weed), the medical community prefers the term “cannabis”. 

Cannabis is grown until it produces a tight cluster of flower buds where most of the plant’s therapeutic compounds are found. These flowers are then harvested and transformed into products for consumption: dried flower, oils, capsules or softgels, edibles, concentrates (e.g. hash) and topicals.

Over 600 chemical compounds have been found within cannabis which can be divided into three basic categories: major cannabinoids [ka-na-bin-oids], minor cannabinoids, and terpenes [ter-peens]. 

Like most plants, cannabis can be bred to display specific characteristics and tone down others (think of apple varieties at the grocery store). This is why there are so many cannabis products to choose from: each has its own signature concentration of compounds that can be tailored to meet your medical treatment goals.  

Cannabis products can be inhaled, ingested or applied to the skin.

Is medical cannabis different from recreational cannabis?

Medical cannabis—or more accurately, cannabis that has been prescribed (or ‘authorized’) for patient use by a doctor or nurse practitioner—is made from the same plant as recreational cannabis, cannabis sativa. Some licensed producers in Canada manufacture cannabis products strictly for the medical market, while others manufacture products for both medical and recreational consumers. 

Authorized medical cannabis isn’t necessarily more concentrated, or “potent”, than what’s available for recreational purposes—although it could be. Like any other medication, what a healthcare practitioner prescribes for specific health conditions depends on the needs of each individual patient. And, like any other medication, a cannabis prescription (usually called an authorization) is not for sharing with others. 

Medical cannabis follows federal regulations, which adhere to strict quality and safety standards and rigorous testing of cannabinoid (THC and CBD) concentrations, along with testing for any pesticides, heavy metals and microbes such as mold or bacteria. Medical cannabis may also be eligible for insurance coverage or compassionate care pricing. 

Whenever you have questions about your cannabis prescription, ask your healthcare practitioner, or consult our Medical Cannabis by Shoppers™ team.

Uses for medical cannabis

Studies involving medical cannabis are ongoing, revealing its ability to help manage symptoms of various conditions. Medical cannabis is often prescribed to patients suffering from: 

  • Pain and inflammation

  • Anxiety

  • Sleep disorders

  • Poor appetite

  • Nausea and vomiting

  • Epilepsy

  • Gastrointestinal disorders (e.g. Crohn's disease)

  • Migraines

  • Mood disorders

  • Neurodegenerative disorders (e.g. Multiple Sclerosis; Parkinson’s)

  • PTSD

What are cannabinoids?

While there are over 100 cannabinoids within the cannabis plant, two major ones dominate: THC (tetrahydrocannabinol) and CBD (cannabidiol). Minor cannabinoids are found in much smaller amounts but can also contribute to the effects patients look for in managing their symptoms, including CBG (cannabigerol), CBC (cannabichromenic acid), CBN (cannabinol) and THCV (tetrahydrocannabivarinic acid). 

The human body also manufactures its own cannabinoids, known as endocannabinoids, which help neurons communicate with each other and regulate the nervous system. Two of these endocannabinoids, anandamide and 2-Arachidonoylglycerol (2-AG), mimic the structure of THC and CBD respectively. 

The  effect of cannabinoids on the human body is considerable, with positive symptom management ranging from managing seizures to mood disorders to pain relief. We now know an extensive network of cannabinoid receptors is found throughout the body: the central nervous system, immune system and endocrine system, as well as within the brain, heart, bones, eyes, reproductive organs, digestive tract, and so much more. This network of receptors is known as the endocannabinoid system. 

Two cannabinoid receptors, called CB1 and CB2, are widespread in the body and uniquely structured to bind to THC and CBD. These receptors act as locks, and cannabinoids the keys, to activate the endocannabinoid system. Under the guidance of a healthcare practitioner, the right balance of cannabinoids may provide benefits that meet your body’s unique needs.

About CBD

What is CBD?

CBD, or cannabidiol, is one of two major cannabinoids within cannabis (the other being THC). CBD is non-intoxicating and therefore won’t get you “high”, or cause a feeling of euphoria, although it does have an effect on the brain. Both cannabis sativa and its non-intoxicating cousin, industrial hemp (which makes paper, textiles, food products, etc.) contain CBD and can be used to make CBD products. 

CBD may work better in the body when taken in conjunction with other chemicals found in cannabis, such as THC and terpenes, in what scientists call the “entourage effect”.

What can CBD do?

When activated by CBD, specialized receptors in the body can have a positive influence on various conditions  such as inflammation, immune response and general well-being. CBD has been used to help with, but is not limited to: 

  • Anxiety

  • Seizures

  • Inflammation

  • Depression

  • Migraines

  • Inflammatory bowel disease

  • Chronic pain

  • Sleep disorders

CBD can also counteract some of the negative side effects of THC, such as anxiety and paranoia. Patients who have had a negative experience with THC in the past can look for products high in CBD. 

Can I take too much CBD?

Consuming too much cannabis is called cannabis poisoning. Because CBD is non-intoxicating, side effects are typically minimal to non-existent. However, CBD can potentially interact with other medications. Plus, many CBD products also contain some of the intoxicating cannabinoid THC, which itself can induce a range of adverse side effects. Talk to a cannabis-trained physician or pharmacist. 

Taking large doses of CBD may not increase the potential for a positive outcome, either. Cannabis products have biphasic properties, meaning smaller doses are sometimes more beneficial than larger ones—a “less is more” idea. If you think you’ve taken too much CBD, call a Medical Cannabis by Shoppers™ team member.

About THC

What is THC?

Cannabis is commonly known for its uplifting and euphoric effects, and the molecule behind this is called THC, or tetrahydocannabinol. Along with CBD, THC is a major cannabinoid that has many beneficial applications. THC may cause some uncomfortable effects in some patients because it has a psychoactive effect on brain chemistry.

What can THC do?

THC binds to specialized CB1 receptors that are mostly concentrated in the brain and central nervous system. These CB1 receptors are responsible for feelings of intoxication, yet also play a role in regulating pain, inflammation, mood, sleep and appetite. Interestingly, CB1 receptors also have landing sites for CBD. When present, CBD can make it harder for THC to bind to these receptors and reduces the psychoactive side effects.  

THC has been used to manage the symptoms associated with, but not limited to:

  • Anxiety

  • Insomnia

  • Muscle spasticity

  • Nausea

  • Appetite

  • Chronic pain

Can I take too much THC?

Excessive THC is called cannabis poisoning and can be very unpleasant for adults. For children, cannabis poisoning can pose increased health risks and require hospitalization. While it is not known to be fatal, too much THC can cause chest pain, rapid heartbeat (tachycardia), nausea or vomiting, severe anxiety or panic attacks, shallow breathing and the possibility of a psychotic episode. 

While a very uncomfortable experience, the symptoms of excess THC will fade as the cannabinoid eventually works its way out of the body. That being said, it can take up to 24 hours for all the effects to wear off. If you think you’ve taken too much THC and are worried, call a Medical Cannabis by Shoppers™ team member or your healthcare provider.


What are terpenes used for?

All the scents and flavours you can find within cannabis, from sweet to skunky, are produced by terpenes. These aromatic chemicals are manufactured by most plants in nature to protect themselves against disease, insects and even other plants. Cannabis produces several hundred different terpenes, with some of the dominant ones being Limonene (citrus-sour), Myrcene (musky-thyme), Pinene (pine) and Linalool (lavender-floral), although cannabis terpene orders and combinations are virtually endless.

About cannabis prescriptions

Who can prescribe cannabis?

A document called a Medical Document (similar to a prescription) grants patients access to medical cannabis products. Any licensed physician or nurse practitioner in Canada can prescribe cannabis, either in person or online. Medical Cannabis by Shoppers offers a convenient online option through our partner HelloMD that allows patients to connect virtually with a healthcare provider for this authorization—sometimes within minutes.

How old do you have to be to get a prescription for cannabis?

Under the Cannabis Act, medical cannabis is available to anyone with authorization from their healthcare practitioner. There are no age restrictions on medical cannabis.

Common cannabis query's

Does cannabis cause brain damage?

Modern brain imaging technologies have proven that cannabis does not cause damage to the brain. While symptoms such as memory loss, confusion and racing thoughts can be a short-term side effect of THC, this is not an indication of brain damage and can be remedied with a dose adjustment, product adjustment, or pause in treatment.

Is cannabis addictive?

It’s estimated a small percentage of the population (about 1 in 11 people) can become addicted to cannabis. However, the risk of addiction to cannabis is considered lower than the risk of addiction to alcohol, tobacco or opioids. Signs of an addiction include a 12-month pattern of failing to perform at work or school, giving up important activities, consuming larger amounts over a longer period than intended, and being unable to cut down on cannabis use. 

Talk with your healthcare practitioner or someone on the Medical Cannabis by Shoppers™ team if you identify with one or more of the negative patterns listed. 

Alternatives to smoking

There are many ways to consume cannabis without smoking. For similar immediate effects, portable or desktop vaporizers let you inhale dried cannabis flower in smoke-free, vapour form. Similarly, vape pens use cannabis distillate or concentrate  that are also inhaled as a vapour. Both vaporizer options have a shorter therapeutic duration, about four to six hours, similar to smoking. 

Cannabis oils, capsules and edibles allow you to ingest the medicine orally. Ingesting cannabis can take one or two hours to take effect, but it also lasts longer, for up to 10 hours. It should be noted that most accidental cannabis poisonings have been from eating or drinking cannabis; it’s easy to consume more before the full effect of the first dose is felt.  

Topicals (creams and lotions) applied to the skin are another way to take medical cannabis. Topicals are considered non-psychoactive because they are not metabolized by the liver, plus CBD crosses the skin barrier more easily than THC. Topicals are typically prescribed for localized pain management and inflammation.

What is considered a low dose?

Healthcare practitioners will typically recommend a very low dose to start, encouraging patients to work up to a level that is comfortable and suitable to their particular needs. 

For inhaled cannabis, a single puff of a low-THC (9% THC or less) strain is generally considered a low dose. Waiting four hours before another puff will allow you to feel its full effect before having more. 

Oils and edibles are easier to measure in terms of dosage. A very low dose is considered 1mg THC. It could take up to two hours to start feeling the effects, which may peak at four hours. Wait eight hours before trying more. 

Finding the right cannabis dose can be challenging, which is why our Medical Cannabis by Shoppers™ team is specially trained in medical cannabis. Don’t hesitate to reach out to our qualified professionals at any point, with any questions. 

How will cannabis effect me?

Will cannabis interact with other medications?

Cannabis can interact with a number of other drugs and herbal products. Talk to your healthcare practitioner or cannabis trained pharmacist about any other medications or supplements you’re taking. Be cautious about taking cannabis with anything that can cause drowsiness: sleeping aids, pain medications, allergy or cold medications and some seizure medications. Cannabis can also interact with stomach acid inhibitors, some heart medications, antibiotics and antifungals, certain antidepressants and antiretroviral drugs used to treat HIV/AIDS.

How will cannabis make me feel?

Each person reacts a little differently to cannabis. While CBD is considered non-intoxicating it can have a mild, relaxing effect. Products containing THC can make you feel any of the following: 

  • Euphoria

  • Relaxation

  • Hunger pangs

  • Drowsiness

  • Feeling chatty or giggly

  • Anxiety 

  • Dry mouth

  • Nausea

  • Headache

  • Confusion

  • Paranoia

Patients typically start with a very low cannabis dose, and slowly increase the amount until finding the dose that works best for their health.

Can I still function in the daytime after consuming cannabis?

Until you know how your cannabis prescription affects you, activities that depend on coordination, major decision-making and staying alert should be avoided. Do not drive. Unlike with alcohol, there is no guidance on how much cannabis is too much to drive safely, nor how long you should wait to drive after consuming cannabis. Also avoid operating heavy machinery.