Things you should know about cannabis

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What it is

Cannabis (marijuana, pot, weed, etc.) is a plant that contains chemicals called cannabinoids, which affect the brain and body. Delta-9-tetrahydrocannabinol (THC) is the cannabinoid responsible for the psychoactive effects (the high) people get from using cannabis.


Edible cannabis products can look like common food and drinks, but may contain THC. The effects of edibles can be unpredictable. It can take longer to feel the effects of edibles. There is also a risk of accidental poisoning, especially for children.

How to identify legal cannabis

Each province and territory has its own stamp for legal cannabis products.

In Canada, legal products that contain THC also have the standardized cannabis symbol on their labels.
Cannabis edibles can be homemade and may not be labeled. It is OK to ask questions so you can make informed decisions.

The related laws

Each province and territory has different laws about cannabis, including the legal age. If you're under the legal age, it's against the law to possess, grow, use and distribute cannabis. Your municipality may also have additional offences linked to cannabis. Get informed on the laws that apply where you live.

Anyone 18 years of age or older who sells or provides cannabis to someone under the age of 18 is liable to up to 14 years in prison.

How it can affect you

The effects of cannabis depend on:

  • who is using it
  • how it is consumed
  • how much is consumed

Cannabis use has risks, especially for youth. Since the brain develops until around the age of 25, young people have a higher risk of facing negative social and health effects.

  • When inhaled (smoked/vaped), effects can begin immediately and last up to 6 hours.
  • When ingested (eaten/drank) effects can begin within 30 minutes to 2 hours and last up to 12 hours.
  • Some effects can last as long as 24 hours.

Driving while impaired is dangerous, and it's a crime. There is no standard waiting time to drive after using cannabis. It's never worth it – stay over, take a cab or use public transit.

Short-term effects

Short-term effects of cannabis may include:

  • impaired memory, concentration, decision-making, and thought process
  • lower attention, impaired coordination and reaction time
  • changes in mood and perception (users could be calm, happy, anxious, paranoid, hallucinating, etc.)
  • increased appetite (munchies)
  • dry mouth
  • increased heart rate

Long-term effects

Early, long-term, and/or frequent cannabis use can increase the risk of:

  • cannabis use disorder and other mental health
  • problems
  • impaired brain function
  • relationship problems
  • other social consequences, such as a difficulty keeping school and work commitments

Mental health

1 in 10 cannabis users will develop a cannabis addiction (cannabis use disorder).

1 in 6 of those who start using as teenagers will develop cannabis use disorder.

Cannabis can worsen existing mental health symptoms and increase the risk of developing schizophrenia, psychosis, depression, and anxiety. The risk is higher for those who have a personal or family history of mental illness.

How to reduce potential risks

Cannabis use is not without risk. It can have important social and health consequences for you.

Get informed and don't be afraid to ask questions.

If you use cannabis, to reduce potential risks:

  • delay using cannabis until later in life
  • reduce the amount and frequency of use
  • choose low-strength products

Check out Canada's Lower-Risk Cannabis Use Guidelines.

Where to get help

In collaboration with:

  • Public Health Agency of Canada
  • Health Canada
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