Street names: marijuana (grass, weed, pot, dope, ganja, 420, reggie, bud, chronic, dagga, herb, green, kush, skunk, hash)
What is it?
Cannabis is a product of the Cannabis sativa plant. It has been cultivated for centuries for medical, social and spiritual purposes.
The cannabis plant contains over 540 chemicals, many of which are called cannabinoids. The two main cannabinoids are THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol). THC has psychoactive effects, which means that it affects your mood, thoughts and perceptions. It causes the “high” that people feel when they use cannabis. CBD does not have these effects. Both CBD and THC have some therapeutic qualities. Cannabis products vary in how much THC and CBD they contain.
What does cannabis look like?
Cannabis products come in many forms and can be used in many ways. When people talk about cannabis, they are often referring to marijuana, the dried leaves, flowers, stems and seeds of the cannabis plant. They can be rolled into a cigarette called a joint, or smoked out of a pipe, or bong.
Other forms include edibles, oils, vapes and con.centrates. Edibles are food or drinks infused with cannabis. Oils (also tinctures and capsules) contain extracted cannabis compounds that are swallowed or placed under the tongue. Vapes heat cannabis oil or flower to create vapor instead of smoke.
Concentrates are stronger extracts that can produce a more intense effect. Resin, a sticky substance containing high levels of THC, is one example. Other concentrates include hashish, which is compressed resin sold in chunks, and shatter, which is a hard, glass-like substance.
What does cannabis look like?
Cannabis products come in many forms and can be used in many ways. When people talk about cannabis, they are often referring to marijuana, the dried leaves, flowers, stems and seeds of the cannabis plant. They can be rolled into a cigarette called a joint, or smoked out of a pipe, or bong.
Other forms include edibles, oils, vapes and con.centrates. Edibles are food or drinks infused with cannabis. Oils (also tinctures and capsules) contain extracted cannabis compounds that are swallowed or placed under the tongue. Vapes heat cannabis oil or flower to create vapor instead of smoke.
Concentrates are stronger extracts that can produce a more intense effect. Resin, a sticky substance containing high levels of THC, is one example. Other concentrates include hashish, which is compressed resin sold in chunks, and shatter, which is a hard, glass-like substance.
What are the laws on cannabis? Cannabis for medical use has been legal in Canada since 1999. In 2018, the Cannabis Act made it legal to produce, sell and use cannabis for recreational purposes. The age to buy and grow cannabis varies across Canada, but the minimum age is 18. In Ontario, people age 19 and older can possess up to 30 grams of dried cannabis and grow up to four plants per household.
People in Ontario can buy non-medical cannabis products through retailers that are licensed by the provincial government. Legal edibles have a limit on how much THC they can contain.
People with a medical exemption from their health care provider can produce or possess more cannabis than the Cannabis Act allows.
Who uses cannabis?
In 2024, 26 per cent of Canadians age 16 and older used cannabis, and six per cent used daily or almost daily. Males were more likely than females to use cannabis.
Many people use cannabis before it is legal. An Ontario survey found that 18 per cent of students in grades 7–12 used cannabis in the past year. The survey also found that up to five per cent of students use every day.
Some people use cannabis for medical purposes. It may be used to treat certain forms of epilepsy and to manage nausea, appetite, pain, depressed mood and insomnia associated with some chronic health conditions. Some people use cannabis to cope with anxiety and depression, but there is no good evidence that it provides long-term relief. It is best to seek guidance from a health care provider before using cannabis for any health concern.
How does cannabis make you feel?
How cannabis affects you depends on:
- the potency (strength) of THC
- how much you use
- how often you use it and for how long you have
- been using it
- whether you smoke it or use it another way
- your mood, expectations and environment
- your age
- whether you have certain medical or mental health conditions
- whether you use alcohol or other drugs at the same time (including over-the-counter and herbal products)
When people first try cannabis, it is a good idea to use only a small amount because they don’t know how they will react. Some people feel relaxed, lively, talkative and giggly, but others feel tense, anxious, fearful and con.fused. The same person can have different experiences from one time to another.
At lower doses, cannabis can slightly change how you perceive things. People often say that it makes music sound better, colours appear brighter and moments seem longer. They also say that it enhances taste, touch and smell, and makes them feel more aware of their body. Some people enjoy these sensations, but others find them uncomfortable.
Stronger doses of THC may intensify the desired effects, but they can also produce negative feelings like anxiety, paranoia and panic. Hallucinations can also occur.
The physical effects of cannabis include red eyes, dry mouth and throat, irritated respiratory system (from smoking) and bronchodilation (expanded airways in the lungs). Appetite and heart rate often increase, while blood pressure, balance and stability decrease. Cannabis may cause drowsiness or restlessness. It may also impair attention, short-term memory and reaction time.
How long does the feeling last?
Smoking cannabis has an almost immediate effect. The noticeable effects last one to three hours, depending on the amount. Cannabis that is ingested (e.g., edibles, oils, capsules) can take up to two hours before it shows effects. This delay means that people might think that the cannabis isn’t working and take more, which can cause stronger effects than they want. It’s safer to wait about four hours before deciding whether to take another dose. The effects of edibles can last up to 12 hours, depending on the amount.
THC is stored in fat cells and expelled from the body over days or weeks, which means that drug tests can detect cannabis long after its effects have worn off, sometimes for one month or more. Cannabis can still affect a person’s functioning even when they no longer feel high.
Is cannabis addictive?
It can be.
People who use cannabis regularly can develop cannabis use disorder. It is an addiction, where the person can’t stop using cannabis even though it causes problems in their life. The person has a strong urge to use, needs to use more to feel the same effect, and may go into withdrawal if they stop. The risk is much higher in people who begin using cannabis before age 18.
Long-term, frequent cannabis use can lead to with.drawal if the person cuts down or suddenly stops. Symptoms include irritability, anxiety, upset stomach, loss of appetite, mood swings, sweating and disturbed sleep. Symptoms peak within the first few days and last one to two weeks. For people who have used heavily and frequently for a long time, withdrawal can last several weeks, and some symptoms, such as sleep problems, may continue even longer.
If you are concerned about your cannabis use or about someone else, seek professional help. Treatment includes talk therapy to help cope with cravings and prevent relapse.
Is cannabis dangerous?
Be aware of the following possible dangers while using cannabis:
- Cannabis-induced psychotic disorder: Large doses of THC, especially in edibles, can cause toxic psychosis. It involves seeing or hearing things that are not there, paranoid thoughts, confusion and memory loss. Symptoms usually disappear within a week of stopping cannabis.
- Impaired driving: Driving under the influence of cannabis is against the law. Cannabis can make it harder to judge distance, focus, react quickly and control your movements.
- Mixing with alcohol: Cannabis and alcohol intensify each other’s effects and can cause severe impairment. This includes poor memory, judgment and coordina.tion, as well as nausea and vomiting.
- Contamination of illegal cannabis: Products purchased outside of a licensed store do not have to meet health and safety standards. They may be contaminated with other drugs, pesticides or toxic fungi.
- Heart risks: Cannabis raises heart rate and lowers blood pressure. The risk of heart attack may increase for people who have heart conditions.
- Pregnancy: Cannabis may affect the fetus and cause cognitive problems in children. Cannabis smoke con.tains many of the chemicals found in cigarette smoke that are dangerous to the fetus.
Frequent cannabis use before age 16 is linked to many problems. People who start using cannabis young have a higher risk of mental health problems, learning chal.lenges and problems at school, injuries and other substance use issues.
Cannabis-related emergency department visits have increased since cannabis became legal, often due to accidental poisoning. Store cannabis safely and know how much THC it contains before you use it. Try not to use alone in case you have a bad experience.
What are the long-term effects of using cannabis?
Heavy or regular cannabis use increases the risk of certain problems:
- Cancer: People who smoke cannabis often hold unfiltered smoke in their lungs for maximum effect. This increases the risk of cancer because smoke contains cancer-causing chemicals.
- Breathing and lung problems: Smoking cannabis can irritate the respiratory system. It is linked to chronic bronchitis, pneumonia and other lung diseases.
- Lethargy: Heavy cannabis use often reduces motiv.ation for work and study. Motivation usually returns when the person stops using cannabis.
- Psychotic disorders: Cannabis can increase the risk of schizophrenia and bipolar disorder, particularly in people who start using at an early age.
- Thinking and memory problems: Chronic, heavy use can impair attention, memory and the ability to process complex information for weeks, months and even years after a person has stopped using.
- Cannabinoid hyperemesis syndrome: This rare condition can affect people who use cannabis for a long time. It causes frequent, severe bouts of nausea and vomiting. The only way to cure it is to stop using cannabis.
Are there safer ways to use cannabis?
If you use cannabis, follow these tips to lower the risks:
- Delay using cannabis for as long as possible. The earlier in life you begin, the higher your risk of serious health problems.
- Choose products with less THC or more CBD than THC. Stronger THC products are worse for your health.
- Avoid synthetic cannabis products. Most of them, like K2 and Spice, are stronger and more dangerous than natural products. They can cause seizures, irregular heartbeat, hallucinations, even death.
- Choose options other than smoking. Vaping is less harmful to your lungs and edibles don’t harm your lungs at all. But keep in mind that all cannabis products can carry other risks.
- Don’t inhale deeply or hold your breath. If you smoke cannabis, these practices increase the amount of toxins that your body absorbs.
- Try to use cannabis only occasionally. The more often you use, the more likely you are to develop health problems or cannabis use disorder.
- Don’t drive or operate other machinery. Avoid these activities after using cannabis or while you still feel affected by it. Mixing cannabis with alcohol or other mind-altering drugs is even more dangerous.
- Avoid cannabis in certain situations. It is safest not to use cannabis if you have a personal or family history of psychosis or substance use problems, or if you are pregnant or breastfeeding.Federal and provin.cial laws cover drinking and driving offences. For more information, see Do You Know… Alcohol, Other Drugs and Driving.
More in this series…
- Alcohol Alcohol, Other Drugs and Driving
- Amphetamines
- Anabolic Steroids
- Benzodiazepines
- Caffeine
- Cocaine
- Ecstasy
- GHB
- Hallucinogens
- Heroin
- Inhalants
- Ketamine
- LSD
- Methadone
- Methamphetamine
- Prescription Opioids
- Tobacco
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