General notice

Regulation of cannabis in Québec

Cannabis was legalized on October 17, 2018. To learn more about the legislation on cannabis and health risks of cannabis use, visit This hyperlink will open in a new window..


Cannabis is a natural drug that is produced from a plant by the same name. It is available in different forms:

  • Dried cannabis
  • Hashish
  • Hash oil
  • Tetrahydrocannabinol (THC) extract

There are also synthetic cannabinoids, which are synthetic molecules that mimic the effects of cannabis.

Cannabis contains over 500 different substances. The two main active ingredients are:

  • THC
  • Cannabidiol (CBD)

For more information about the composition of cannabis, go to the Description and Composition This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

What it is calledAppearance Characteristics
  • Weed
  • Pot
  • Grass
  • Dope
  • Ganja
  • Mary Jane
  • Herb
  • Skunk
  • Chronic
  • Blunt
  • Flower
  • Roach
  • Leaves, stems or dried flowers


Marijuana can be smoked on its own. It is sometimes mixed with tobacco.

It can be rolled in the shape of a cigarette called a joint, smoked in a pipe or added to muffin or cake recipes.

The smoke has a strong smell. 

  • Hash
  • Cube
  • Dime
  • Bag
  • Chocolate
  • Beige, brown or black viscous resin from the cannabis plant that has been dried
  • Hashish is sold in small, compact cubes.

Hashish sold on the black market is often mixed (cut) with other substances, such as henna, shoe polish, candle wax or tar.

It can be heated on a knife. However, it is typically crumbled and smoked like marijuana. 

Hash oil 
  • Resin
  • Liquid hashish
  • Thick oil from marijuana or hashish
  • Black, dark green, reddish-brown or yellow 

Hash oil is typically placed on a cigarette or mixed with tobacco and then smoked.

It is stronger than other cannabis products, given its higher THC content.

THC extracts

  • BHO
  • Honey
  • Oil
  • 710
  • Dad
  • Shatter
  • Budder
  • Wax
  • Ear wax
  • Black glass
  • Errl
  • Wax
  • Paste

These extracts are a lot stronger than other forms of cannabis because they contain more THC.

Synthetic cannabinoids
  • Spice
  • K2
  • Incense
  • Dream
  • Dried leaves
  • Oil

Synthetic cannabinoids are synthetic molecules the mimic the effects of cannabis. However, they may be stronger because their active ingredients are generally stronger than those found in cannabis.

Synthetic cannabinoids found on the black market are usually produced in clandestine labs. They should not be used.

Note that some synthetic cannabinoids may have the status of drugs that must be prescribed by a doctor.

Effects of cannabis

Cannabis may cause the following:

  • A feeling of well-being
  • An impression of calmness and relaxation
  • A tendency to be more talkative than usual or have a spontaneous desire to laugh
  • Increased self-confidence
  • Changes in perception: colours appear more vibrant and sounds more distinct, for example
  • An impression of being more open-minded, creative and imaginative
  • A distorted perception of time (time passes more slowly), space, self-image
  • A false impression of being able to do a complex task or fulfil an important responsibility more easily
  • Impaired attention and concentration
  • Impaired short- and medium-term memory
  • Impaired judgement
  • Swelling of blood vessels (e.g., red eyes)
  • Increased appetite
  • Dry mouth and throat
  • Drowsiness
  • Increased heart rate
  • Slower reaction time

The duration of the effects of cannabis varies from person to person. It also depends on the amount of cannabis consumed and how it is consumed (inhalation, ingestion). To find out more about what influences the effects, go to the Effects of drugs page.

For more information, go to the How it Affects You This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

Risks associated with cannabis consumption and possible consequences

Cognitive impairment in regular users

Regular, heavy cannabis users (5 joints or more a week) may experience:

  • impaired memory (immediate and delayed), attention and concentration;
  • impaired ability to organize, integrate and process complex information.

Some cognitive deficits can persist for a few weeks after stopping use, but are reversible even in heavy users.

Cognitive impairment in teenagers

For teenagers, heavy use at a young age can interfere with brain development. Teenagers should use as little as possible during this period, especially before 16 years of age.

Mental health risks

Cannabis use is associated with mental health risks. It can cause:

  • symptoms of depression;
  • anxiety;
  • psychotic symptoms, such as hallucinations or paranoid thoughts (in most cases, these symptoms only appear when intoxicated and resolve on their own).

For more information about the possible consequences of cannabis use for mental health, go to the Health Risks of Cannabis Use This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

Effects on the respiratory system

Cannabis use may have an adverse effect on the respiratory system. A cannabis joint contains up to 50% more tar than a single popular-brand cigarette. People who smoke cannabis usually inhale deeply. Smoking 1 joint can therefore be as harmful as smoking 4 to 10 cigarettes. Using cannabis also increases the risk of an emphysema or asthma attack in people with these diseases.

Risk of developing cannabis dependence

Dependence is defined as a state of adaptation resulting from the use of one or more substances that create physical or psychological needs. The risk of developing cannabis dependence is estimated at:

  • 9% in all users;
  • 17% in users who initiated use in adolescence;
  • 25% to 50% in daily users.

To find out more, go to the Dependency (addiction) section on the Problems Associated with Alcohol Consumption and Drug Use page and the Health Risks of Cannabis Use This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

Risks during pregnancy and breastfeeding

THC consumed by the mother is found in the placenta and in breast milk. Therefore, it is best to avoid using cannabis and its derivatives and exposure to second-hand smoke during pregnancy and while breastfeeding. For more information, go to the Health Risks of Cannabis Use This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

Possible consequences of cannabis on ability to drive

Cannabis use can affect the user’s ability to drive:

  • slower reaction time;
  • impaired attention;
  • difficulty maintaining a straight course;
  • decreased ability to properly assess the environment;
  • decreased vigilance;
  • coordination problems;
  • impaired judgement.

Driving under the influence of cannabis increases the risk of having an accident. Driving under the influence of drugs such as cannabis is also illegal and can be detected by the police. To find out more about these risks, go to the Risks of Driving Under the Influence of Cannabis This hyperlink will open in a new window. page on the Regulation of Cannabis in Québec site.

Help and resources

Last update: October 17, 2018


Information on the website in no way replaces the opinion of a health professional. If you have questions concerning your health status, consult a professional.


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