Now that recreational cannabis is legalized in Canada, many first-time users are looking at cannabis with a curious eye. However, before you try cannabis recreationally, you may be asking, “How will cannabis affect me?”

Today, we answer this question and many more as we explore in depth how cannabinoids affect the body.


These chemical compounds are the main active constituents of the cannabis plant. Cannabinoids are absorbed by the body and transported by the bloodstream around the body to interact with cannabinoid receptors.

There are over 100 identified cannabinoids found in the cannabis plant, including the two most abundant – tetrahydrocannabinol (THC) and cannabidiol (CBD). Because they come from plants, cannabinoids like THC and CBD are classified as phytocannabinoids.

These phytocannabinoids mimic the roles of the body’s naturally-occurring cannabinoids or endocannabinoids like anandamide and 2-AG to manipulate the body’s systems and provide its many varied effects.

Endocannabinoids such as anandamide and 2-AG function as neurotransmitters, sending chemical messages between neurons throughout the nervous system. They directly affect the nervous system to influence a wide range of functions, including

  • pleasure
  • memory
  • thinking and concentration
  • movement
  • coordination
  • sensory and time perception
  • immune response
  • mood
  • appetite and metabolism
  • sleep
  • and more

The Role of the Endocannabinoid System

The neural communication network that uses these cannabinoid neurotransmitters, known as the endocannabinoid system, plays a critical role in the nervous system’s normal functioning.

CBD and THC’s chemical structures are similar to those of 2-AG and anandamide. Because of this similarity, these phytocannabinoids are able to interact with cannabinoid receptors on neurons in the central and peripheral nervous systems, altering various mental and physical functions and causing the effects we experience when using cannabis.

When a person consumes cannabis, cannabinoids like THC and CBD pass into the bloodstream. The blood carries the compounds to the brain and other organs throughout the body, where they interact with cannabinoid receptors.

When smoked, the short-term effects of cannabis manifest within seconds and are fully apparent within a few minutes. These effects will typically last for 1–3 hours, depending on the person and the strength of the product consumed.

After oral ingestion of cannabis, the onset of effects is delayed by digestion, taking 30 minutes to 2 hours to fully take effect. However, the duration of effects is prolonged due to continued slow absorption.

Recreational and Therapeutic Effects of Cannabis

Cannabis is regularly consumed for recreational or therapeutic reasons. For some users, it is both. This difference sometimes determines whether consumers use cannabis high in CBD or high in THC.

Recreational cannabis users will typically prefer cannabis strains with more THC than CBD. Some of the primary effects that high-THC, recreational cannabis users report are the following:

  • altered physical senses (for example, seeing brighter colors)
  • altered perception of time
  • changes in mood (euphoria)
  • feelings of creativity
  • relaxation
  • impaired body movement

Therapeutic cannabis users may choose a product high in CBD or THC, depending on their desired effects. If you are considering using cannabis products therapeutically, we suggest doing research or consulting your doctor to best understand its wellness effects.

Side Effects of Cannabis

Cannabis, whether it is high in THC or CBD has relatively benign side effects. Common side effects of cannabis use may include

  • dry mouth
  • increased appetite
  • drowsiness
  • increased heart rate
  • slowed reaction time
  • lightheadedness
  • red eyes

Many of these side effects are minor and can be addressed by sitting down with a glass of water or a snack for a moment and taking a break. It is advised not to use high THC cannabis before or when handling heavy equipment, driving, or tasked with something important.

Long-term Health Effects

New and experienced user of cannabis may be concerned about the potential long term effects of cannabis use. These effects are also minimal, especially when compared to other drugs.

Unlike with many other recreational and medical drugs, there has never been an overdose death linked to cannabis. Since there are no cannabinoid receptors found in the brainstem, which is responsible for critical functions like breathing, cannabis use will not cause an overdose death.

However, fully evaluating the long-term health effects of marijuana has been difficult, as there have been few comprehensive studies with a long enough duration to effectively judge possible long-term effects, especially when compared to similar drugs. However, results recorded in studies thus far are promising.

One longitudinal study shows that people who smoke cannabis for extended periods of their lives showed no serious negative health effects, especially when compared with cigarette smokers. Many of the effects listed in this study, such as diminished lung function and impaired cardiovascular health, though minimal in marijuana users, can be averted by choosing a cannabis consumption method other than smoking.

Another study looked at marijuana and alcohol users aged 14-55. Researchers found alcohol consumption to be associated with lower gray matter volume and poorer white matter integrity in the brain. These negative structural changes in the brain, however, were not observed in those who had used cannabis within the past 30 days, demonstrating that cannabis doesn’t carry the same long-term effects on the brain as other recreational drugs like alcohol.

Researchers from Arizona State University tracked the cannabis use of over 1,000 New Zealanders from birth to middle age to see what effect those habits have on some common measures of physical health, including lung function, inflammation, cholesterol levels, blood pressure, body weight, blood sugar, and dental health. With the exception for dental health, cannabis use had no negative effect on any measure of health. People who consumed more cannabis had a higher incidence of gum disease.

With many valued positive effects and minimal negative side effects, users are often comfortable adding cannabis to their routines both in the short term and the long term.

Want to Learn More?

There is always more to learn on the Real Scientific blog.

Written by:
Jeffrey Stamberger Jeffrey Stamberger