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How Does Cannabis Affect The Body

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JoshuaHolt JoshuaHolt
Added 22 January 2021

How Does Cannabis Affect The Body

Many of us use cannabis but do not know how it interacts with the body. Cannabis is a diverse plant that affects people in different ways but there are distinct biological and chemical processes happening for all of us when we consume cannabinoids. Understanding our own biology and how cannabis can communicate with it can give a lot more meaning to the experience and allow us to use it safely and responsibly. Read on to learn all about why we get high from marijuana and how its effects can change over time.

Is Cannabis Healthy For Humans?

Is Cannabis Healthy For Humans

Cannabis has proven to be extremely beneficial in the lives of thousands of users. It has become hard to deny that cannabis has the potential to treat all sorts of conditions and is relatively harmless if used in the correct way. Cannabis has an extensive list of healthy positives and has saved lives in some cases.

Whether cannabis is healthy or not depends on how it is used but it does make sense when we understand why it affects us in the way it does. It has been shown that cannabis correlates with the biology of all mammals living on planet Earth.

In the right doses, THC and CBD can help to regulate our bodies in ways that can actually boost our immune systems.

People have safely consumed cannabis for thousands of years and there are still no reported overdoses. It seems the only way to die from cannabis is through suffocation, which would be impossible unless you smoked so much you deprive your body of oxygen. Anyway, it is unlikely anyone would reach this stage and would probably be passed out or asleep way before.

The Endocannabinoid System

The Endocannabinoid System Regulates Many Bodily Functions

The body regulates itself through chemical transmissions sent between a network of neurons found throughout the body and brain. These messages are sent out via presynaptic cells in the neurons, which then get passed through a synapse and received by a postsynaptic cell on a separate neuron, which then communicates the response. This communication is constant and helps to regulate functions such as emotion, thoughts or physical movement.

The endocannabinoid receptors are neurotransmitters found in nearly all our organs and work to keep our bodies in a state of homeostasis. Homeostasis is the body's ideal state of balance, where everything is functioning correctly and in full health. Our bodies have naturally occurring endocannabinoids that stimulate the endocannabinoid system to keep us healthy, but phytocannabinoids (plant-based cannabinoids such as THC) also interact with it.

Quality Tested Cannabis Is Always Safest

What's interesting about the endocannabinoid system is that it works differently than other neurotransmitters found in the brain or body. When presynaptic cells are triggered by the ingestion of THC or CBD, the postsynaptic neurons receive a transmission and begin to produce cannabinoids. These cannabinoids are then sent back through the synapse to the presynaptic cells and fuse with the cannabinoids at the receiving end.

The endocannabinoid system is then controlling how much of that signal gets sent and received by the presynaptic and postsynaptic cells and therefore, which chemicals the body needs to produce and in which quantity. 

CB1 and CB2 Receptors

CB1 And CB2 Receptors

There are two types of receptors that make up the endocannabinoid system. The CB1 and CB2 receptors send and receive signals to and from different parts of the body. CB1 receptors are most apparent in the brain and central nervous system.

CB2 receptors on the other hand, are found scattered across our organs, although some areas of the body include both receptors. It has been shown that CB2 receptors can also be found in the nervous system. Each presents a unique set of actions when phytocannabinoids attach themselves to the receptors.

CB1 Receptors

CB2 Receptors

    • Memory
    • Learning
    • Pain
    • Appetite
    • Metabolism
    • Inflammation
    • Allergies
    • Stress
    • Autoimmune conditions
    • Neurodegenerative diseases.

The Effect Of THC and CBD

The Effects Of THC Can Last For Hours

The effects of cannabis are felt almost instantly when it is smoked or vaporized. The THC enters into our bloodstream directly through the lungs and meets with CB1 and CB2 receptors across different organs. Signals are sent to our brain within minutes. The effect last between 1-3 hours.

Eating it, on the other hand, takes longer to get an effect. Cannabinoids consumed via the stomach have to be digested before being absorbed. This process, as you probably know, can take up to an hour or two, but of course depends on one's body weight and metabolism. The high can last between 4-8 hours, depending on the dose.

THC (tetrahydrocannabinol) is the main active compound in cannabis that makes users feel high. It stimulates the part of our brain that produces dopamine, which is the same chemical that makes us feel pleasure. THC activates CB1 and CB2 receptors.

CBD (cannabidiol) is the cannabinoid second most present in cannabis. CBD interacts with the endocannabinoid system but it also expresses itself through other pathways. Users do not experience a 'high' from consuming it because it is not psychoactive and mainly targets CB2 receptors. Put simply, CBD does not activate CB1 or CB2 receptors. Rather it changes the way they work.

This is why THC and CBD have different effects when used together or separately. Higher concentrations of one or the other also changes how the body responds. We must bear in mind that there are other cannabinoids (such as CBN) still being studied which also interact with the effects of cannabis.

Tip: CBD inhibits the effect of THC.

Vaporizing, Smoking and Edibles

Vaping Vs Smoking Vs Edibles

Depending on how you consume cannabis, it can affect the body in distinct ways.

  • Vaporizing - Vaporizers make efficient use of the cannabinoids and terpenes we are after. They make up to 95% of the vapor, depending on the vaporizer and quality of the cannabis. Vaporizers tend to be one of the healthier ways of consuming cannabis.
  • Smoking - Burning cannabis produces chemical compounds that are toxic for the body. Combustion burns off a good portion of the cannabinoids and terpenes so users tend to consume more weed to get high than they would with a vaporizer.
  • Edibles - Cannabis edibles usually last longer and deliver a stronger effect than when the cannabinoids are inhaled through the lungs. This is due to the way the cannabinoids are metabolized through the liver. In the liver, Delta 9-THC converts to 11-hydroxy-THC, which passes through the blood-brain barrier more easily, with more power and for longer.

How Cannabinoids Affect The Body

Smoking Cannabis Delivers An Almost Instant Effect

There are many reported effects of cannabis use, both positive and negative. Some people find it beneficial while others can have serious psychological problems develop because of it. Therefore, much of it depends on the physiology and psychological function of the person, as we just mentioned. Although there are many different ways cannabis can affect humans, here are some of the more common effects:

  • Appetite, aka 'the munchies'
  • Dehydration and thirst
  • Impaired judgement
  • Memory loss
  • Ease of sleep/Drowsiness
  • Release of dopamine
  • Positive or negative emotions and thoughts
  • Increased/decreased anxiety or depression
  • Withdrawal symptoms
  • Pain Relief

Nervous System

The Hippocampus In The Brain

Cannabinoids interact with our central nervous system and areas of the brain which deal with for example, how we balance ourselves. This means cannabis can disorientate and mess with our reflexes. Over long periods of use it may have a lasting impact, especially if the brain is not yet fully developed.

THC affects an area of the brain called the hippocampus, which regulates our ability to memorize things. Consuming cannabis at an early age can hinder the development of the hippocampus and therefore is likely to have a long term effect on memory or the ability to learn and retain information.

On the positive side, cannabis has also shown to reduce pain or inflammation throughout the nervous system. Many users consume marijuana because it makes them feel relaxed. In addition, there have been a number of successful cases where cannabis has been used to treat seizures, like those caused by epilepsy.

Note: Both short term or prolonged use has shown that dopamine levels in the brain can diminish and there is the possibility the user feels depressed or anxious during or after consuming cannabis.

Circulatory System

Consuming Cannabis Can Make The Eyes Turn Red

Cannabinoids are transported through our bloodstream to our organs. THC increases the heart rate and blood pressure (which is why it is often associated with anxiety attacks or psychological problems), while CBD inhibits these responses and often causes the opposite.

It seems CBD can help to reduce heart rate in stressful situations but can also speed it up in non-stressful situations. Blood pressure may be lowered in both cases.

Red eyes are a common occurrence after consuming cannabis because the blood vessels swell up. As the arteries dilate, blood pressure is lowered. There have been positive studies based around how cannabis can be used to help treat glaucoma, a disease which increases pressure in the eyes, causing damage to optical nerves and tissues.

Respiratory System

Users Can Develop Respiratory Problems From Long Term Cannabis Use

Smoking cannabis isn't as unhealthy as smoking tobacco, but it still produces a number of chemicals which are toxic to the body. Chronic users can eventually get lung problems as their bronchioles begin to clog up. Bronchitis can develop over the long term. Smoking cannabis is not recommended for those who have respiratory conditions such as asthma or those that are suffering from a cold, cough, or allergy problems.


Cannabis Edibles

Consuming cannabis is known to increase appetite and this could be because it gives us the sensation of a particular food being more appealing than it normally would. We are essentially tricking our bodies into thinking we're hungry. In a study done on mice fasting for 24 hours, the results showed an increase in the natural cannabinoids produced in the part of the brain that deals with their ability to smell or taste.

Cannabis has also shown promising results in helping to treat problems with the gastrointestinal tract, 'such as inflammatory bowel disease (especially Crohn's disease), irritable bowel syndrome, and secretion and motility-related disorders.'

Tip: Nausea and vomiting are two possible effects of consuming cannabis orally.

How Terpenes Affect The Body

Terpenes Found In Cannabis

There are hundreds of different types of terpenes found in all sorts of plants, fruits and vegetables across the world. Cannabis shares many of these same terpenes, such as limonene, a terpene found in lemons.














Inhibits Memory Loss


Appetite Suppression


The Entourage Effect

There is much evidence that suggests that THC and CBD work syngergistically. Also known as the 'Entourage Effect', the effects of THC are said to change in the presence of CBD and vice versa. They compliment each other but have many benefits and uses on their own too.

Like THC and CBD, terpenes may work in synergy with cannabinoids to produce slightly different effects. This is still being studied, but it has been shown as chemical compounds change through drying and curing, so do the effects of the cannabis itself. 

Trichomes on Purple Lemonade (Fast Buds) by Removeduser from GrowDiaries.

Tip: Terpenoids are terpene extracts.

Cannabis Tolerance

The Release Of Dopamine Is Was Gives Humans The Feeling Of Pleasure

People eventually build a tolerance to cannabis because they do not allow enough time for the dopamine levels in their brain to readjust. If we are constantly introducing THC, the body doesn't have a reason to produce it's own cannabinoids. THC residue is also stored in our bodies for a period of time before it becomes undetectable.

THC has even been detected in finger nails and hair up to 3 months after consumption.

How long cannabinoids remain in your body depends a lot on your body weight, size and how much cannabis you have consumed. Have a look at this chart to see how long it takes on average for cannabinoids to filter out of the system after smoking cannabis as a casual smoker (2-3 times per week):

Salivaup to 3 days
Blood7 - 21 days
Urineup to 21 days
Sweatup to 30 days
Hairup to 90 days
Nailsup to 90 days

THC metabolites (11-COOH-THC ) can be stored in different parts of the body and can get released back into the bloodstream. This has been proven in studies, where test subjects who had consumed cannabis were asked to exercise for short periods of time, whereupon their blood showed increased THC levels than before the exercise session.

Tips For Using Cannabis Safely

Tips For Using Cannabis Safely

We must consider both the short term and long term effects of cannabis use. Then there is also the frequency of use and the dosage. Whether we are talking about THC or CBD, there are a few factors that should be taken into account when we study how people can experience cannabis differently:

  • Body Weight
  • Metabolic Rate
  • Current Age
  • Amount Consumed
  • Frequency Of Consumption
  • Method Of Consumption

A fully grown adult can consume cannabis safely if the right doses are taken. Dependancy is possible and can bring an array of psychological problems. Development of young people's brains can become seriously affected if they become frequent/heavy users.


As cannabis culture grows and it becomes more accepted across the world, studying how it work is as relevant as it has ever been. After all, cannabis is natural and many people are drawn to it for this very reason. Whether you are interested in cannabis for recreational or medical reasons, there are plenty of benefits to be discovered. However, be cautious on your journey and respect your body so you do not end up with any negative effects.

If you found this article useful or have any experiences you want to share with the community, please feel free to leave a comment down below!

External References

Hair drug testing results and self-reported drug use among primary care patients with moderate-risk illicit drug use. - Gryczynski, J., Schwartz, R. P., Mitchell, S. G., O'Grady, K. E., & Ondersma, S. J. (2014).

Residual blood THC levels in frequent cannabis users after over four hours of abstinence: A systematic review. Drug Alcohol Depend. - Peng YW, Desapriya E, Chan H, R Brubacher J. (2020)

Cannabinoid Receptors in the Central Nervous System: Their Signaling and Roles in Disease. - Kendall, D. A., & Yudowski, G. A. (2017).

Is the cardiovascular system a therapeutic target for cannabidiol? - Br J Clin Pharmacol. Stanley CP, Hind WH, O'Sullivan SE. (2013)

Neuroprotective effect of (-)Delta9-tetrahydrocannabinol and cannabidiol in N-methyl-D-aspartate-induced retinal neurotoxicity: involvement of peroxynitrite. Am J Pathol. - El-Remessy AB, Khalil IE, Matragoon S, Abou-Mohamed G, Tsai NJ, Roon P, Caldwell RB, Caldwell RW, Green K, Liou GI(2003)

The endocannabinoid system controls food intake via olfactory processes. - Soria-Gómez, E., Bellocchio, L., Reguero, L. (2014).

Δ9-Tetrahydrocannabinol (THC), 11-Hydroxy-THC, and 11-Nor-9-carboxy-THC Plasma Pharmacokinetics during and after Continuous High-Dose Oral THC. - Eugene W Schwilke, David M Schwope, Erin L Karschner, Ross H Lowe, William D Darwin, Deanna L Kelly, Robert S Goodwin, David A Gorelick, Marilyn A Huestis. (2009)

Behavioral Pharmacology of THC and Alpha-pinene. - Johns Hopkins University

Blood cannabinoids. I. Absorption of THC and formation of 11-OH-THC and THCCOOH during and after smoking marijuana. J Anal Toxicol. - Huestis MA, Henningfield JE, Cone EJ. (1992).

Cannabis sativa Terpenes are Cannabimimetic and Provide Support for the Entourage Effect Hypothesis. - LaVigne, Justin & Hecksel, Ryan & Keresztes, Attila & Streicher, John. (2020).

Disclaimer: This article does not provide medical advice. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment.

This article was updated January 2021.



I'm the first to comment. :smiley: I eat the flowers . I'm in my fifties , smoked cannabis every day since being a teenager. Back when I was young and naive. A teenager we would get high as fuc. I soon realized that smoking less got me just as high . Longer intervals between smoking the better the high.

How cannabis effects you. Why is it cannabis strains have so many different effects? It must be a synergistic effect from THC delta 9 cannabinoids and terpenes.

This makes cannabis a very complex drug that is difficult to assess it's effects.

Let's face it : teenager s are curious. If a drug is taboo it's alluring to try. I wish this accurate and non threatening article was used as eduction for parents and teenagers . No teenagers are not supposed to drink alcohol or do drugs. Yet most of us did right?

The better we are all educated the better we can make good decisions.

A friend of mine has a unique form of epilepsy. He has tried dozens of drugs to have a normal life. The side effects from most of these drugs were terrible. Most drugs were maybe effective at best. Then through research he read about CBD. For him it's the only drug that works . It's not a perfect cure but essentially there are no side effects that are detrimental .

One more thing : testing THC. There no way that a flower by weight is 20 to 25 % THC. Try weighing the plant material which has no THC then weigh just the trichromes with out the capitate stalks. That's the stem to the trichromes. Then factor in that trichromes are a mix of THC , cannabinoids and terpenes.

What is being tested is just the trichromes as they are soluble in alcohol or whatever solvent is used.

The trichromes are getting larger amounts of cannabinoids , this has been happening for thousands of years as man selects what plants to breed.

The common misconception is that cannabis is now more (dangerous) as it's much more potent. Which is odd because 20 years ago I grew potent indica that you could only smoke half a joint and you had serious couch lock!

Many of the properties of Cannabis have been bred out in favour of low smell( lower terpenes) and alcohol s. Including cannabinoids. Fortunately we now understand cannabinoids are a good thing. The very complex nature of the plant is constantly modified by mans intervention from breeding cannabis. It's can be a very safe recreationally used drug. It's also as legal research is now starting to be allowed and recognized, an important drug for healing many maladies with out serious detrimental side effects.


Concuerdo su pensar y respetó su experiencia.
Educar evita tener ignorancia y tener ignorancia atrae errores negativos.
Sí Dios la donó vía madre tierra nosotros somos los responsables de cuidarla y usarla tanto positiva cómo negativamente.


Me identificó varios ítems dados en el desarrollo del artículo. Tengo 41 años y se ahora la responsabilidad de hacer uso cómo medicamento natural.
Gracias por su información