Cannabis
Cannabis (also known as marijuana or weed) is a psychoactive substance that became legal for recreational use under the Cannabis Control Act on October 17, 2018. In Ontario, it is accessible to adults aged 19 and older.
As students navigate this time of increased independence, it's important to make informed choices about cannabis use. Cannabis can affect cognitive functions, mental well-being, and motor skills—particularly for young adults, whose brains are still developing.
Health Canada provides evidence-informed guidelines to support lower-risk cannabis use. The guidelines summarized in this section aim to help individuals make safer, more informed decisions about their health and well-being.
Cannabis
Cannabis
Understanding Cannabis Use
Impacts of Cannabis Use
Health Effects of Cannabis
Cannabis affects the brain and body in different ways, depending on how it is consumed. When smoked or vaporized, its effects can begin within seconds and last up to 24 hours. When ingested in food or beverages, the effects may take 30 minutes to 2 hours to appear and can also last up to 24 hours.
Short-Term Effects
Cannabis can cause feelings of euphoria, relaxation, and enhanced sensory perception. However, it can also lead to:
- Confusion, fatigue, anxiety, or panic
- Impaired memory, concentration, and reaction time
- Increased heart rate and decreased blood pressure
- Risk of psychotic symptoms like paranoia and hallucinations
Long-Term Effects
Frequent use over time may result in:
- Addiction
- Reduced cognitive function (e.g., memory, decision-making, IQ)
- Lasting damage to attention and mental performance, especially in adolescents
- Lung issues similar to those caused by smoking tobacco (e.g., bronchitis, chronic cough)
Age-Specific Effects
Youth (13–17) and young adults (18–25) are more vulnerable to the harmful effects of cannabis due to ongoing brain development.
Pregnancy and Breastfeeding
Cannabis use during pregnancy or breastfeeding may harm the baby, potentially causing:
- Low birth weight
- Delays in memory, attention, and problem-solving skills
- Hyperactivity and increased risk of substance use later in life
Cannabis, Hormones, and Reproductive Health
Research suggests that females and individuals with higher estrogen levels may be more sensitive to the effects of cannabis. Those undergoing hormone replacement therapy have also reported changes in how they experience cannabis. Fertility research shows that regular (e.g., weekly) cannabis use may reduce sperm count in individuals with sperm-producing organs. Additionally, cannabis use may disrupt the menstrual cycle and ovulation in those with egg-producing organs.
Therapeutic Uses
Cannabis and its cannabinoids may have therapeutic benefits. Health Canada provides guidance for medical use, including:
- Approved therapeutic uses
- Dosage information
- Risks and side effects
Using Cannabis Safely
Choose Wisely – Opt for cannabis products with lower THC and higher CBD levels to reduce the risk of negative effects. Avoid synthetic cannabinoids like K2 or Spice, which are unpredictable and linked to serious health complications.
Mind Your Method – Avoid smoking when possible. Consider safer alternatives such as vaporizers, edibles, or tinctures. If you do smoke, avoid deep inhalation or holding your breath, which increases exposure to harmful toxins.
Pace Yourself – Start low and go slow. Especially with edibles, the effects can take 30 minutes to 2 hours to appear. Give it time—wait at least 2 hours before considering more.
One at a Time – Stick to one substance at a time. Mixing cannabis with alcohol, nicotine, or other drugs can lead to unpredictable and intensified effects on your mind and body.
Practice Safe Sharing – Avoid sharing joints, bongs, or vaporizers to reduce the risk of spreading germs, colds, flu, and COVID-19.
Plan for Safety – Cannabis impairs your ability to drive. Never drive or operate machinery for at least 6 hours after using, and longer if you’ve consumed a large amount or combined it with other substances. Plan ahead for a safe ride home.
Know Your Source – Only purchase cannabis from legal, licensed retailers to ensure the product is tested and labelled for potency, THC/CBD levels, and contaminants.
Set and Respect Your Limits – Know your personal boundaries and communicate them clearly. Don’t feel pressured to use more than you’re comfortable with.
Be Aware of Your Environment – Use cannabis in safe, familiar places and with people you trust—especially if you’re new to using or trying a new product or method.
Consider Your Mental Health – Cannabis use can worsen or trigger mental health concerns such as anxiety, depression, or psychosis, particularly in people with a personal or family history of mental illness. Reflect on how cannabis affects your mood and well-being.
Know the Law – Remember that cannabis is legal for adults 19+ in Ontario, but there are restrictions. It is illegal to use it in some public places (like campuses), share it with minors, or carry more than the legal limit (30 grams in public).
Staying Informed: Policies and Laws
Cannabis Laws in Ontario: What You Need to Know
Cannabis Laws in Ontario: What You Need to Know
How Old Do You Have to Be?
- You must be 19 or older to buy, use, possess, or grow recreational cannabis.
How Much Can You Have?
- You can carry up to 30 grams of dried cannabis (or equivalent) in public.
- At home store it safely and securely and keep it away from children.
For more information on possession - Cannabis Act (federal) 8 (1) = subsection 8 pinpoint 1
Where Can You Use It?
- Smoking of any kind, including cannabis and vapes, is not permitted on Humber property, in compliance with the Ontario Smoking Laws and Humber’s Smoking Policy
- Private homes (if allowed by the property owner)
- Outdoor public spaces (like sidewalks or parks—unless otherwise prohibited)
- Hotel rooms (designated smoking rooms only)
- Parked RVs or boats if they’re being used as a private residence
Where You Can’t Use It
- Indoor shared spaces in condos, apartments, or student housing
- Enclosed public places (like restaurants, malls) and workplaces
- Schools and spots where kids gather
- Hospitals, care homes, and similar facilities
- Public parks, playgrounds, and beaches
- Near schools or childcare centres (within 20 metres)
- Vehicles or boats, if they’re being used for travel (even if you’re not the driver)
Cannabis and Driving
- Never drive high. It’s illegal and unsafe.
- Cannabis must be sealed and out of reach in any vehicle or boat (like in the trunk or a locked compartment).
Medical Cannabis
- Different rules may apply if you’re using cannabis for medical reasons. Always check with your healthcare provider or refer to government resources.
Cannabis Supports and Resources
| Supports/Resources | Descriptions |
|---|---|
| Knowing Your Limits with Cannabis | A free self-directed workbook developed by the Canadian Centre on Substance Use and Addiction to help adults reflect on their cannabis habits, assess risk levels, and implement practical harm reduction strategies. |
| Health 811 | Provides a free and confidential, 24/7 phone and chat service in Ontario that connects users with registered nurses and reliable health information for non-emergency situations. |
| BounceBack | A free guided self‑help program run by the Canadian Mental Health Association that helps people aged 15 and up who are experiencing mild-to-moderate anxiety or depression, or may be feeling low, stressed, worried, irritable or angry. |
| ConnexOntario | Offers free, confidential 24/7 provincial helpline and online resource that connects Ontarians with mental health, addiction, gambling, and problem gaming support. |
| Canada’s Lower-Risk Cannabis Use Guidelines | A CAMH publication with evidence-based recommendations for lowering the risks of cannabis use. |
| YMCA Youth Cannabis Awareness Program | Provides free harm-reduction-based programming and resources for youth, parents, and professionals. |
| YouthREX What's with Weed | Offers free and accessible cannabis information—videos (including Indigenous health content), French-language resources, and support for Ontario’s grassroots youth sector. |
| Cannabis and Mental Health | A free youth-oriented online resource (also in French) that helps youth understand how cannabis impacts mental health and learn harm-reduction strategies. |
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