Skip to main content Skip to Navigation Skip to Footer
page banner image

Cannabis: What you need to know

In light of cannabis legalization, the Porcupine Health unit advises that legal does not mean harmless. Cannabis can have negative effects on your physical and mental health.

What can I do?

We urge people to:

  • know the risks
  • talk to your children
  • encourage those who choose to use cannabis to be considerate of all community members
  • help reduce second-hand exposure

What is cannabis?

Cannabis has many other names such as: grass, weed, pot, dope, green, blunt, reefer, hashish (hash), hash oil, Mary Jane/MJ, shatter, or dabs. All forms of cannabis come from the dried flower buds and leaves of the Cannabis Sativa plant. It ranges in colour from greyish green to greenish brown and may contain seeds and stems.

 Cannabis contains hundreds of different types of cannabinoids, which are chemical substances specific to the cannabis plant. The main cannabinoids are:

  • THC (delta-9-tetrahydrocannabinol): THC is the main psychoactive cannabinoid (a chemical compound affecting the mind) and is most responsible for the “high” associated with cannabis use.
  • CBD (cannabidiol): CBD has little or no psychoactive effects and counteracts some of the negative effects of THC.

Cannabis can come in different forms such as dried plant material or processed products like oils and waxes that are consumed by smoking, vaping or ingesting (eating or drinking). Each product can come with differing amounts of THC and CBD.

The law

As of October 17, 2018, the Cannabis Act legalized access to non-medicinal cannabis across Canada. On October 17, 2019, the act was amended to include rules related to the production and sale of edible cannabis, extracts, and topicals.

There are strict laws in place to keep cannabis out of the hands of children and youth, therefore only those 19 years of age or older can buy, use, possess and grow cannabis. Even if you are of legal age, there are restrictions regarding purchasing, possession and consumption of cannabis, with penalties for individuals who break the laws. Remember, it’s illegal to sell or distribute cannabis to anyone under 19 years of age.

You cannot smoke or vape cannabis in any location where smoking tobacco is banned. This includes any enclosed workplaces, enclosed public places or places designated as smoke-free and vape-free. It is also illegal to smoke or vape cannabis on or within 20 metres of school property, childcare centres, or playgrounds.

For more information about the laws concerning cannabis purchase, possession and consumption, please visit the Ontario Cannabis Legalization webpage.

Health effects

Cannabis use has well-documented short and long-term physical and mental health effects. Some of the risks of using cannabis include:

  • problems with concentration, memory, coordination and judgment
  • mental health problems, such as anxiety, depression, hallucinations and even psychosis
  • impaired ability to drive safely (including recreational vehicles and heavy machinery), leading to fatal and non-fatal injuries
  • chronic respiratory or lung problems from smoking
  • reproductive problems
  • cannabis dependence
  • cannabinoid hyperemesis syndrome (severe nausea and vomiting)

Risks also increase:

  • with the frequency of cannabis use
  • with use of higher THC cannabis products
  • when cannabis use is combined with other psychoactive substance (e.g. alcohol, prescription medications)

Not using cannabis is the best way to prevent these risks.

Cannabis use is a personal choice. If you have decided to use cannabis, follow Canada’s Lower-Risk Cannabis Use Guidelines to reduce your risk.


Edible cannabis

Edible cannabis, also known as edibles, are products that you eat or drink which contain THC and/or CBD. There is a wide range of edible products, and although some products may look like normal food items, they are not intended to provide any nutritional value. If you choose to consume edible cannabis, know the risks as they affect you differently than inhaling cannabis

Edible cannabis products by-pass respiratory-related risks. However, there are other risks associated with edibles, such as it takes longer to feel the effects, the effects are stronger and last longer that a similar dose of inhaled cannabis. The intoxicating effects do not kick in for about 30 minutes to 2 hours and can take up to 4 hours to feel the full effects. Effects can last up to 12 hours after use with residual effect lasting up to 24 hours. Taking more before feeling the effects can result in over-intoxication. Wait. Go slow.

Edible cannabis may look appealing to children and youth, so make sure they are properly labelled, locked up and stored out of sight and reach of children and youth. Poisoning could occur if children or youth unintentionally eat edibles which could lead to serious health problems.

Cannabis and pregnancy

Cannabis use before, during and after pregnancy, and while breastfeeding, can be harmful to a baby. The chemicals from cannabis can pass from a woman’s body to the baby during pregnancy, and from breastmilk to a baby when breastfeeding. To avoid any possible negative health effects, it is safest to avoid all forms of cannabis use while pregnant or breastfeeding.

Cannabis and youth

Brain development in youth and young adults can be negatively affected by cannabis use. The brain continues to grow and change until a person is approximately 25 years old. When cannabis, alcohol, or other drugs are introduced during this critical time in brain development, it can disrupt the way these connections are made.

Cannabis use can also increase the risk of developing a mental illness, especially in youth and young adults. It's an addictive substance so starting use at an early age can increase the likelihood of a person developing a problem. Regular cannabis use, before the age of 25 can also increase a person’s risk of developing psychosis, schizophrenia, depression, and/or anxiety disorders.

What can parents do?

Parents are important role models and have a big influence on their children. Children tend to copy what they see, therefore using cannabis around your children not only exposes them to the risks of second-hand smoke, but it may also influence their choice to try cannabis as well.

Remember, cannabis may affect how parents interact with their children, and lowers their ability to make good decisions and attend to their children's needs. The effects of cannabis can last for several hours. If you plan on using, ensure to always have a sober caregiver for your baby, child or other dependent.

One of the best things a parent can do is to talk to their children about cannabis. Start the conversations early, be open, and talk often. The Cannabis Talk Kit is a resource parents can use to learn tips and strategies on how to have these important conversations.

For more information:

Cannabis - Health Canada
Information regarding cannabis, legalization, health effects, addiction, medical use and traveling with cannabis. ’s webpage.

Cannabis - Government of Ontario
Learn about recreational cannabis and where you can buy it in Ontario and find resources on its health effects.

Cannabis – Canadian Centre on Substance Use and Addiction
Information on cannabis in general as well as policies and regulations, research and publications related to cannabis.

Cannabis – Centre of Addictions and Mental Health 
Additional information about cannabis, including links where you can find help, treatment and support.



Health Effects of Cannabis - Health Canada
This factsheet that provides information about the potential health risks associated with using cannabis.

How To Safely Store Your Cannabis - Canadian Centre on Substance Use and Addiction
Infographic about learning how to store cannabis safely.

Cannabis: Inhaling vs Ingesting - Canadian Centre on Substance Use and Addiction
To lower your risk of the harmful effects of cannabis, you need to understand the differences between the two most common ways of consuming it.

7 Things You Need to Know about Edible Cannabis - Canadian Centre on Substance Use and Addiction
If you’re interested in trying edible cannabis, here are seven things you need to know.

Edible Cannabis: Always read the label - Canadian Centre on Substance Use and Addiction
Infographic that illustrates what people should know before consuming edible cannabis, including reading the label to understand how much THC a product contains, and the importance of staring low

What's with weed? - The Youth Research and Evaluation eXchange
Are you a young person in Canada? Looking to learn more about cannabis?


Cannabis Talk Kit - Drug Free Kids Canada
This resource provides information about cannabis along with some effective tools to help parents set the stage for a conversation about cannabis and engage in productive discussions with your teen.

Cannabis: What Parents/Guardians and Caregivers Need to Know - The Centre for Addiction and Mental Health
This resource provides information about cannabis, cannabis legalization, risks of using cannabis, signs of a problem, how to help your child, and where to get more information and support.

Parents: Help Your Teen Understand What’s Fact and Fiction About Cannabis - Canadian Centre on Substance Use and Addiction
Learn about what is fact and fiction when it comes to cannabis.


Risks of Cannabis on Fertility, Pregnancy, Breastfeeding and Parenting - Best Start Resource Centre
This resource provides information about the effects of cannabis use on fertility, pregnancy, breastfeeding, on children and adolescents when their mothers used cannabis during pregnancy and on parenting.


Where to get help

Health811 Offers fast and free medical advice. Services are available 24/7.

ConnexOntario provides free and confidential health information for people living in Ontario who are experiencing problems with alcohol and drugs, mental illness or gambling. Services are available 24/7.

Kids Help Phone is a 24-hour anonymous counselling service available in Canada for children and youth.

The Ontario Poison Centre is a consultation services to assist with treating poisonings and drug overdoses. This service can be contacted if your child has consumed an edible cannabis product.