Consuming a lot of cannabis can cause serious short-term effects. These include, but are not limited to: 

• Feeling sleepy or confused 
• Trouble moving properly 
• Slow reaction time 
• Problems with thinking, remembering, and making choices 
• Low blood pressure (which can make you faint) 
• More mucus in your throat 

Some effects of cannabis can last for more than 24 hours, even after other effects wear off. Mixing cannabis with alcohol or other substances makes these effects stronger and more dangerous. 

Taking too much cannabis or taking it by accident can result in cannabis poisoning. It doesn't usually cause death, but it can cause: 

• Chest pain 
• Fast heartbeat 
• Nausea or vomiting 
• Seeing or hearing things that aren't real (hallucinations) 
• Thinking people are out to get you (paranoia) 
• Trouble breathing 
• Feeling very anxious or panicked 

Children and pets are more likely to get poisoned by cannabis. 

Eating or drinking cannabis is more likely to cause poisoning than smoking or vaping it. That’s because some cannabis foods and drinks look like regular snacks, and it takes longer to feel the effects. People might take more before realizing they’ve had too much. 

If you're experiencing a cannabis poisoning: 

• Stop using it 
• Get medical help or call your local poison control centre 

Using cannabis can lead to long-term problems, like: 

• Damage to blood vessels from smoking 
• Breathing problems like, bronchitis or lung infections 
• Chronic (long-term) cough 
• Mental health issues, like anxiety, depression, eating disorders, and suicide 
• Substance use disorder, which may involve: 
• Difficulty completing duties at work, school, or home 
• Giving up hobbies and other activities 
• Using more and more over time, even when you didn’t plan to 
• Being unable to cut down or control cannabis use 
• Spending too much money on cannabis 

Cannabis affecting your mental health is more likely when: 

• You start using cannabis at a young age 
• You use cannabis a lot (daily or almost every day) 
• You or someone in your family has had mental health issues, like psychosis or schizophrenia 

• Health Effects Info Sheet 

Using cannabis while pregnant or breastfeeding can be dangerous for the baby. It may lead to: 

• The baby being born too small (low birth weight), which can cause other health problems 
• Trouble paying attention or being too hyper as your child grows older 
• A bigger chance of your child using substances later in life 
• Cannabis chemicals going into breast milk and reaching the baby 

• Cannabis Before, During and After Pregnancy Info Sheet 

If you choose to use cannabis, here are some ways to stay safer:  

• Only use cannabis that is bought from stores that are licensed to make sure it is safe and uncontaminated. 
• Wait until you’re older to use it (25+). Your brain keeps growing until age 25. 
• Choose products that don’t have a lot of THC, or ones that have more CBD to THC. 
• Don't use synthetic cannabis products like K2 or Spice. 
• Avoid inhaling deeply or holding your breath when smoking cannabis. 
• Try to use as little as possible. 
• Don't drive or use machines after using cannabis, or while you still feel affected by cannabis. 
• Do not use cannabis if you are pregnant or breastfeeding. 
• Avoid cannabis if you or someone in your family has a history of psychosis or substance use problems. 
• Avoid using cannabis with tobacco or other substances. 

For more information about lower risk cannabis use, we recommend these resources: 

• Canadian Public Health Association - Harm Reduction, Health Promotion and Cannabis Screening Tools 
• Canada's Lower-Risk Cannabis Use Guidelines Brochure 
• Canada's Lower Risk Cannabis Use Guidelines Full Guide  
• Here to Help - Safer Cannabis Use   

In 2018, it was made legal for adults 19 and older to buy, own, and use cannabis. The goal of the law is to keep people safe by: 

• Making it harder for youth to get cannabis 
• Reducing illegal cannabis sales 
• Making sure cannabis sold in stores meets quality and safety requirements