Cannabis

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Cannabis, also known as marijuana, weed, pot, dope, or hash, is a product of the cannabis sativa plant used for both psychoactive and therapeutic effects. It is typically green, brown, or grey and comes from dried flower buds and leaves.

The main psychoactive chemical in cannabis is THC (tetrahydrocannabinol), which produces the “high” experience. Another chemical in cannabis is CBD (cannabidiol), which does not cause psychoactive or “high” effects but can cause drowsiness. CBD is being studied for medical uses. Long‑term effects of CBD use are unknown.

Cannabis comes in many forms, including dried flowers and leaves; hash; extracts such as oils (for example, honey oil and phoenix tears) and shatter; and edibles (e.g., candies, butter, or baked goods). It can be smoked, vaped, or ingested through food or drink.

Since October 17, 2018, cannabis has been legal for recreational use for people aged 19 and over in Ontario.

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Cannabis is available in various forms, including fresh or dried flower, oils, extracts, tinctures and sprays, and creams. The THC content of each variety varies. Cannabis can be used in many ways:

  • Inhaling, smoking: effects begin within seconds to minutes and can last 6 to 24 hours.
  • Ingesting, sublingual: effects begin in 10 to 30 minutes and can last 6 to 12 hours.
  • Ingesting, oil‑based: effects begin in 10 to 60 minutes and can last up to 12 hours.
  • Ingesting, food: effects begin in 30 minutes to 2 hours and can last 12 hours or more.
  • Topicals: onset is variable and effects can last 6 hours or more.

Synthetic Cannabis: Another product is synthetic cannabis (man‑made), also known as “K2” or “Spice.” It is not natural cannabis. It is illegal and often more dangerous because unregulated chemicals are sprayed onto shredded plant material. Purchase cannabis only from legal, regulated sources.

Health Effects: Cannabis affects people in different ways. Effects of being “high” can include feeling happy and relaxed, increased sociability and heightened sensations, decreased attention span, increased heart rate, slowed reaction times, trouble thinking and problem‑solving, and losing track of time.

Potential Short‑Term Effects of Single or Occasional Cannabis Use:

  • Relaxation, calmness, or happiness
  • Feeling “high” or euphoric
  • Impaired memory, thinking, or judgment
  • Anxiety, fear, restlessness, or confusion
  • Paranoia, delusions, or hallucinations
  • Fatigue
  • Decreased blood pressure, which can cause an individual to faint and fall
  • Increased heart rate

Cannabis can impair judgment, decision‑making, and perception, which may lead to dangerous situations such as driving while high. If you are under 21, there is a zero‑tolerance law for impaired driving, which means you cannot have any alcohol or drugs in your system. Impairment can also increase the risk of harm to self or others.

Potential Long‑Term Effects of Regular and Prolonged Cannabis Use:

  • Harms memory, concentration, and decision‑making
  • Negatively impacts mental well‑being, and can worsen symptoms of anxiety and depression
  • Interferes with school, work, social, and family responsibilities
  • Damages the lungs and respiratory system (if smoking or vaping cannabis), such as lung infections, bronchitis, or chronic cough
  • Affects brain development for people under 25 years of age
  • Can lead to cannabis use disorder or dependence, making it hard to cut back or stop. The risk increases for those under 25 years of age.
  • Increases the risk of experiencing psychosis and schizophrenia. The risk increases for people under 25, with regular use, or with a family history of these conditions.

Canada’s Lower‑Risk Cannabis Use Guidelines
Using cannabis is a personal choice, but it can have short‑ and long‑term effects on your health. Cannabis can affect your thinking, physical coordination and control, and increase your risk of injuries. Read more

Cannabis Edibles
Edible cannabis products have many different appearances and ingredients, including how much THC and CBD are in them. Most cannabis edibles look like regular food items such as candy and chocolate. Read more

Children and pets are at greatest risk of cannabis poisoning due to accidental consumption. Cannabis should be stored out of sight and locked away from children and pets. To prevent serious harm, know the signs of cannabis poisoning and actions to take to seek help for yourself and others.

Cannabis Poisoning: Cannabis can be overconsumed, leading to high levels of THC in the bloodstream and unwanted effects. Effects are often temporary, but can lead to dangerous situations, sometimes requiring emergency medical attention. Symptoms can include:

  • Chest pain
  • Rapid heartbeat
  • Nausea or vomiting
  • Severe anxiety or panic attacks
  • Suicidal thoughts, and/or psychosis (paranoia, hallucinations, delusions)

Edibles increase the risk of poisoning because products can be confused with non‑cannabis foods, and the delayed onset may lead to taking more, thinking effects will happen sooner.

Eating cannabis raw will not produce intoxicating effects; cannabinoids must be heated to activate THC. In the case of purchased edibles and some oils and tinctures, the THC has already been activated and can be consumed as prepared.

Cannabis and Driving: There is no safe level of cannabis use for driving. Cannabis impairs coordination, attention, concentration, and reaction time, increasing the risk of crashes and serious harm. Delay driving for as long as possible after use. A vehicle includes cars, trucks, boats, snowmobiles, and off‑road vehicles.

Cannabis and Youth Although the legal age of cannabis use in Ontario is 19, people aged 25 and younger are at the highest risk of harms from cannabis.

The parts of the brain affected by cannabis are responsible for memory, decision‑making, problem‑solving, and emotional regulation. Alterations to the developing brain put youth at higher risk of addiction and health problems associated with cannabis use.

To reduce risk, delay the onset of use as long as possible.

Cannabis and Fertility, Pregnancy, Breastfeeding, and Parenting There is no safe amount or safe time to use cannabis when trying to get pregnant, during pregnancy, when breastfeeding or chest feeding, and when parenting. The safest choice is to refrain from cannabis use and inform your health care provider for support.

  • If you are unable to stop using cannabis, or do not want to stop using cannabis, try using smaller quantities and less often.
  • If you are using cannabis for medical purposes, talk to your health care provider for safer alternatives during pregnancy and breastfeeding.

Cannabis and Pregnancy Handout

Parenting: There are various reasons to be cautious about using cannabis while parenting. Parenting while using cannabis may reduce the ability to make good decisions and protect children from harm.

It is best to refrain from cannabis use when parenting to ensure the safety of children and others around. Ensure there is always someone available who is not consuming cannabis to take care of a child and their needs.

Parents are encouraged to continue to learn about the effects of cannabis as new information becomes available. For more information, call your health care provider and visit the links below.

Cannabis and Older Adults: Cannabis use by older adults is increasing. Being informed of the risks associated with cannabis use and healthy aging leads to safer decisions about use.

There is limited research about how the body processes cannabis as individuals age. For older adults, cannabis use today is different than earlier in life, as the potency of THC has increased. For this reason, it is important to be aware of the current health and safety risks of cannabis use.

  • Cannabis can impair concentration and memory, motor skills, and reaction time. This increases the risks of falls and injury and can impair the ability to drive safely. These abilities naturally decline with age, and cannabis can further impair them.
  • Using cannabis can affect your medications. It is important to discuss possible interactions with your health care provider or pharmacist.
  • Lower kidney function and digestion associated with aging can affect how cannabis and other substances are cleared from the body.
  • Smoking cannabis can lead to respiratory problems and worsen symptoms in those with pre‑existing respiratory conditions such as coughing, wheezing, and shortness of breath.
  • In people with pre‑existing heart conditions, cannabis use may increase the risk of heart attack or stroke because cannabis can affect heart rate and blood pressure.

The other information on this page applies to older adults in addition to the statements in this tab.

Parents: Youth and Cannabis Use
Frequent and regular cannabis use that begins early in adolescence and continues over time has been associated with increased risk of harms, some irreversible. Since youth brain development continues to the age of 25, cannabis use during adolescence has serious effects on brain development and function. Read more

Know where to go for help. If you need support with your cannabis use, resources are available to help in your community:

Emergency Crisis Lines: If you need help in an emergency or are in crisis, contact a local distress centre:

  • Emergency: Police/Fire/EMS: call 9‑1‑1
  • SOAR, 24‑Hour Crisis Line: 519‑759‑7188
  • Brantford Police Services and St. Leonard’s Response Unit: 519‑759‑7188
  • Health Connect Ontario (previously Telehealth Ontario): 1‑866‑797‑0007 or call 8‑1‑1
  • Canadian Suicide Prevention Helpline: call or text 988.

If you are concerned about your cannabis experience or are experiencing harmful effects, help is available:

  • Stay calm
  • Do not use any more cannabis
  • Have something to eat and drink water
  • Do not drive
  • Call the Ontario Poison Control Centre at 1-844-764-7669, or call 9‑1‑1

If you believe your child has consumed cannabis, help is available:

Brantford/Brant Addiction Services:

Haldimand-Norfolk Addiction Services:

Provincial and National Help Lines

  • Canadian Drug Rehab Services, call 1‑877‑254‑3348
    • Free, confidential professional help and resources for drug and alcohol addiction in Canada. Referrals for clients seeking support with substances
  • ConnexOntario, call 1‑866‑531‑2600 or text CONNEX to 247247
    • 24/7 Mental Health and Addiction Services support for ages 18+
  • Get help with substance use – Canada.ca
  • Good2Talk, call 1‑866‑925‑5454 or text GOOD2TALKON to 686868
    • Confidential support services for post‑secondary students.
  • Health811 (previously Health Connect Ontario), call 1‑866‑797‑0007 or call 8‑1‑1
    • 24/7 confidential support for health matters and addiction concerns
  • Kids Help Phone, call 1‑800‑668‑6868 or text CONNECT to 686868
    • Support for ages 0‑20