When is it most risky to consume cannabis? Are there ways to reduce potential harms?

If you choose weed, use tips on this page to reduce risks and avoid negative consequences like “greening out” (over-consumption). To be on the safe side, for certain groups of people and times of life, weed should be avoided.

Who Should Avoid Weed?

It’s best to avoid weed if:

Your brain is still developing (until age 25).

You have a history, or family history, of substance use problems or mental illness, especially schizophrenia or psychoses.

You are pregnant:

  • Substantial evidence exists for an association between smoking cannabis and low birth weight, but evidence of associations with other pregnancy or newborn problems is currently limited or insufficient
  • Better research is needed, but it’s always recommended women do not use cannabis while pregnant

You are breastfeeding:

  • THC is released into breast milk
  • There are no appropriate studies to determine whether or not cannabinoid exposure through breast milk is safe or increases risks to the baby, but until there is evidence, it’s best to abstain if you are a breastfeeding mom

individual making decisions


Harm Reduction Strategies

If you do choose weed, use as safely as possible to reduce the likelihood of harm. Know when it should be avoided to complete certain tasks properly and safely. Here are some important harm reductions strategies:

Start Low and Go Slow

Everyone may react differently to weed. If you go all in too fast there is a heightened risk for greening out (feeling sick, paranoid and anxious).

  • If you are new to weed, only take one puff/inhalation to see how you react; wait for effects to occur before you take another hit (30 minutes)
  • If you ingest cannabis, eating a small amount of the cannabis product (2.5mg-5mg dose) and wait at least two hours before having any more to ensure you don’t consume too much
  • Choose products with high CBD and low THC (5-10% THC) or similar ratios of CBD and THC 

Know the Source of Your Weed

  • Legal sources will label the contents, potency (how much THC) and ensure it has been tested for quality 
  • Illegal cannabis may be sprayed with unknown chemicals or include other materials to increase weight, and it may be much stronger or weaker in THC than expected—it can be dangerous

Use Safer Smoking Practices

  • Avoid deep inhalations or holding in the cannabis smoke as long as possible
  • Majority of THC is absorbed in the first few seconds, so breath holding does not increase the effect

Do Not Combine Using Weed with Other Substances

  • Tobacco - Can lead to nicotine addiction and long-term harm to your respiratory and cardiovascular systems
  • Alcohol or other drugs - Can increase effects of cannabis leading to increased anxiety, vomiting and fainting, cardiovascular effects and increase impaired decision-making potentially resulting in accidents, injuries, or unwanted sexual contact/assault. It can increase the time it takes to metabolize alcohol causing alcohol poisoning, which can, in severe cases, lead to death
  • Medication - Can be a dangerous combination. You have no idea of knowing the reaction you could have from mixing cannabis with medications you take (prescription or non-prescription)

Limit Use

  • Limit the amount of cannabis consumed at any given time to avoid over-consumption
  • Use cannabis less frequently - this will reduce many of the risks associated with cannabis use, including the development of cannabis use disorder, which is highest for those who use cannabis every day.

Choose Less Risky Products

  • Choose less potent cannabis products 
  • Choose products with CBD
  • Do NOT consume synthetic weed (K2/Spice), it is plant matter sprayed with a synthetic chemical mimicking high levels of THC as well as other potentially toxic chemicals and can lead to serious harm or death 

Choose Safer Methods of Consumption 

  • Vaporizing is safer than smoking in terms of inhaling harsh chemicals found in combusted plant matter
  • If using a bong, joint, or pipe be mindful to avoid spreading germs
  • If ingesting, don’t over-do it—remember the effects are delayed, more intense and last longer

Do Not Use Weed and Drive 

  • Driving high after consuming weed doubles your chance of being in a motor vehicle accident; there is no defined recommended wait time for safe driving, so it’s best not to drive at all, or get into a vehicle driven by someone else who has used weed
  • The age group most likely to drive after using weed is between 15-19 years. Help change that statistic! (There is zero tolerance for novice drivers and those under age 22 years)
  • Always plan a safe ride home ahead of time - public transportation, a taxi, or a friend / family member. 

Research shows that using cannabis:

  • Slows your reaction time
  • Shortens attention span and concentration
  • Weakens motor coordination 
  • Reduces effective decision-making abilities  
  • Impairs ability to judge distances and time


Weed and Driving Do Not Mix!!!
Check out four short gamified videos to understand why.

In an Instant

A message from the government of Canada

Refrain from Using Weed When You…

  • Babysit. Babysitting requires you to be coherent, and like driving, you need to make decisions that affect others’ lives.
  • Go to school. All schools have policies against using or arriving at school under the influence of cannabis. Weed can interfere with your ability to learn and you don’t need the hassle of getting suspended, do you? 
  • Go to work. Employers have policies against being impaired at work. Why risk losing your job and the money you make? If your job required operating any kind of machinery, being high could have a dangerous outcome for not only yourself, but your co-workers too.
  • Participate in sports. While using cannabis you may misjudge your ability or coordination when participating in various sports activities which could become an unsafe combination. You could also face being suspended from a team.
  • Are alone. Don’t use alone if new to weed. Everyone reacts differently, make sure sober people are there in case of emergency.

Know Your Limits:  Avoid Over-Consumption

Over-consumption means too much THC has been consumed resulting in a “bad high.” Technically, this is a cannabis overdose which can lead to hospitalization or accidents that could cause serious injuries - however, overdose is not quite accurate as its often colloquially used to refer to overdose deaths, and over-consumption of cannabis has never resulted in death. 

Edibles are commonly the culprit. People don’t wait to feel the delayed, intense effects of ingested cannabis before they ingest more, or don't really know how much THC is in what they are consuming. Know the signs and what to do:


Signs and symptoms of over-consumption

  • Severe nausea or vomiting
  • Increased heart rate and blood pressure
  • Chest pain
  • Anxiety
  • Paranoia
  • Panic attacks
  • Extreme confusion
  • Loss of contact with reality
  • Seizures

What to do if you or someone else consumes too much THC?

  • Help them feel safe and comfortable in a quiet space
  • Have them drink water and eat a small snack or meal
  • Encourage them to take deep, slow breaths
  • Do not force the person experiencing the cannabis sickness to vomit
  • If the person is experiencing severe symptoms contact your poison control centre, a healthcare provider, or call 911

Preventing Over-Consumption 

  • Choose lower THC products
  • Always start with 2.5 mg of THC or less
  • Limit ingested THC to 10 mg or less
  • Do not consume more cannabis before you feel the effects of the first “hit” or dose
  • Keep cannabis products safely stored so children and pets cannot access it

Copyright © Government of the Northwest Territories

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