Cannabis (also known as marijuana, pot or weed) comes from the Cannabis sativa plant. The plant contains hundreds of chemicals called cannabinoids that affect the brain and other parts of the body. The two most well-known cannabinoids are:
All cannabis use has potential health risks. Cannabis products come in a variety of forms and can be consumed using different methods (Health Canada).
People use cannabis for different reasons. Some people may use medical cannabis for health-related needs. Others use it for personal, social or recreational reasons. Some people use cannabis for both purposes. Cannabis has the same health and safety risks whether you’re using it for medical or non-medical purposes.
Medical cannabis is used to help manage symptoms, such as pain, nausea (for example, for chemotherapy patients) or anxiety.
In Canada, medical cannabis is regulated under the federal Cannabis Act. To access cannabis under the federal system, a health care provider must authorize its use.
With this authorization, you can:
Learn how to access cannabis for medical purposes from a licensed producer.
If you are planning to use cannabis for a medical purpose, talk to your health care provider. Discuss the pros and cons of using cannabis to treat your medical condition. Ask about possible interactions between cannabis and other treatments you are taking.
For more information:
Non-medical cannabis is legal in Canada. In B.C., people over the age of 19 can legally buy non-medical cannabis from:
Learn more about cannabis in B.C. (Government of B.C.), including laws and regulations.
Cannabis can affect your brain, body, mood and perception in positive ways and negative ways.
Some of the short-term effects include:
Cannabis can also cause unwanted or unpleasant side effects, such as:
Long-term use of cannabis can harm your:
The long-term harmful effects appear worse for people who begin consuming cannabis during adolescence.
Cannabis hyperemesis syndrome (CHS) is a health concern associated with long-term, frequent use of cannabis. It may also be associated with the use of high-THC products. Symptoms include repeated episodes of severe nausea, vomiting and stomach pain.
Learn more about the health effects of cannabis (Health Canada).
Cannabis affects people differently and depends on a variety of factors. Impairment can last for more than 24 hours after cannabis use, well after other effects may have faded.
If you take cannabis by smoking, vaporizing or dabbing:
If you eat or drink cannabis:
Be extra cautious if you are not used to eating or drinking cannabis products that contain THC. Start with a low dose (such as 2.5 mg THC) and wait until you feel the effect before deciding if you want to take more. This could mean waiting 2 hours or more before increasing the dose.
Call 9-1-1 or Poison Control at 1-800-567-8911 if you or someone else is experiencing unpleasant effects from too much cannabis.
Using cannabis has higher risks if you:
For more information:
No amount of cannabis is safe during pregnancy and breastfeeding. Cannabis use during pregnancy can affect a developing baby (fetus). The chemicals in cannabis can cross the placenta. Cannabis use during pregnancy is associated with low birth weight.
The chemicals can also pass from the mother's breast milk to the baby during breastfeeding. This can cause problems including drowsiness and poor suckling. It may be harder for your baby to get enough milk.
Exposure to cannabis during pregnancy and breastfeeding may affect a child’s brain development, learning and behaviour. Talk to your health care provider if you have questions about cannabis use during pregnancy and breastfeeding.
For more information:
The only way to avoid risk is not to use cannabis. If you choose to use cannabis, these tips may help reduce harm:
For more information, read Canada's Lower-Risk Cannabis Use Guidelines (PDF 734KB, Centre for Addiction and Mental Health).
If you're around someone who is smoking cannabis, you may feel some effects of the drug. People who are allergic to cannabis may be more sensitive to second-hand cannabis smoke.
To protect others from second-hand smoke, smoke cannabis outside or choose a room where you can open a window or use a fan to get the smoke outside.
It is important to store cannabis products responsibly to keep others safe. Take care to prevent accidental cannabis poisonings in children and pets.
Always store cannabis products:
If you think a child may have consumed anything with cannabis, call Poison Control at 1-800-567-8911 or 9-1-1 immediately.
For more information:
Do not drive if you have used cannabis. Driving while impaired by drugs is dangerous and illegal. Cannabis impairs your judgement and ability to react and increases your chance of being in a crash.
Cannabis affects every person differently. There is no standard or safe time to wait before driving after using cannabis. Instead, stay over, call a taxi, share a ride, use public transit or have a designated driver.
For more information:
Cannabis use can lead to dependency. Avoid cannabis if you have a personal or family history of psychosis, addiction, issues with substance use.
People with continued, frequent and heavy use of cannabis can develop psychological and/or mild physical dependence. People with psychological dependence may be preoccupied with using cannabis.
Cannabis dependence is medically known as cannabis use disorder. It can range from mild to severe. Signs of cannabis use disorder include:
For more information, please visit:
If you are experiencing cannabis dependency, help is available:
Find further information about cannabis from your local health authority:
Call toll-free in B.C., 8-1-1, or 7-1-1 for the deaf and hard of hearing to get personalized assistance. Speak to a navigator who can guide you to reliable health information or connect you with a health professional. Translation services are available in over 130 languages.
