CBD And THC: Which One Makes You Sick And Which One Makes You Feel Better?

CBD And THC: Which One Makes You Sick And Which One Makes You Feel Better?
So far, we have isolated over 100 cannabinoids in cannabis, of which THC and CBD are the most common ones. What are their differences and similarities? Is it true that one can make you sick but the other can make you feel better?

For years, THC has been notorious as a psychoactive, intoxicating cannabinoid that gives a sense of “high” to people. Because of its psychedelic properties and its adverse health effects, THC is categorized as illegal by most government authorities.

However, the tide is turning. As an increasing amount of research is performed on THC, discoveries are emerging regarding THC’s potential in terms of helping with conditions such as glaucoma, nausea, and anxiety, among others.

Partly as a result, an increasing number of countries are legalizing the use of medicinal or even recreational THC use, including several American states. These don’t include the United Kingdom, where consumption of THC is still classified as a class B drug and is illegal.

This seeming discrepancy between CBD, which is legal in the UK, and THC stems from the fact that their effects on the body and their interaction with the human endocannabinoid system are quite disparate despite their similar chemical structure.

CBD and THC: same molecular structure

CBD and THC have the same molecular structure, which consists of 30 hydrogen atoms, 21 carbon atoms, and 2 oxygen atoms. These atoms are, however, arranged differently. One arrangement gives us CBD while another gives us THC.

CBD and THC chemical structure

Hemp vs cannabis

A major difference regarding CBD and THC is the cannabis plant where they come from.

For CBD to be legal in the United Kingdom, it needs to be produced from industrial hemp. While industrial hemp belongs to the cannabis family, it has been selectively grown to contain significant quantities of CBD but only traces of THC, below the 0.3 or 0.2% level required by law.

Industrial hemp only has minute elements of THC, so it is a particularly poor source of THC. Instead, cannabis (“marijuana”) is used to produce THC. Cannabis plants typically contain 12% of THC, with some strains reaching up to 30%. Cannabis growers selectively grow cannabis strains for their THC content, drought resistance, and any other desirable qualities.

The high THC level is why cannabis growth is strictly forbidden in the UK. It is even illegal to produce CBD from cannabis instead of industrial hemp, even though cannabis typically contains significant amounts of CBD as well. The handful of cannabis growers across the UK require specific licences and undergo stringent inspections.

CBD and THC: their reach in the human body

The human endocannabinoid system

In the last decades, we have discovered that the human body is equipped with a human endocannabinoid system (ECS).

Our ECS is responsible for keeping our body in balance, a task called homeostasis. Our ECS controls several bodily functions including appetite, mood, memory, motor perception, temperature perception, inflammation, reproduction, metabolism, and immune system responses among others.

Two human cannabinoids

Our ECS works with endocannabinoids—cannabinoids that are produced by the body. So far, the scientific community has discovered two such cannabinoids, named anandamide and 2-AG.

These two cannabinoids bind to their respective receptors, called CB1 and CB2, and alert the body when something is amiss and requires fixing. Anandamide binds to CB1 and 2-AG binds to CB2.

CB1 receptors are mostly present in the brain. CB2 receptors are found in the gut, the immune system, and—to a lesser degree—the brain.

The purpose of anandamide

Anandamide takes its name from Sanskrit, where it means ‘bliss’. Anandamide is the cannabinoid that helps the brain feel pleasure and joy.

Besides creating a feeling of elation, anandamide helps our brain generate the nerve cells that are necessary for proper brain function and health. Interestingly, elevated levels of anandamide were also associated with decreased fear as shown in a 2015 study.

Anandamide was also found to help alleviate anxiety, as a 2019 study observed. Further research pointed to anandamide’s potential in helping with cardiovascular conditions.

Several trials and studies have shown that anandamide levels noticeably increase after people exercise, which makes exercise a potential tool in keeping your brain happy.

The purpose of 2-AG

As for 2-AG, it is responsible for regulating our appetite and coordinating our immune system. It has also been found to be helpful with pain management.

Research suggests that 2-AG is involved in the triggering and suppression of epileptic crises while studies have displayed that 2-AG plays a significant role in the health of our cardiovascular system.

CBD, THC, and the endocannabinoid system

Research shows that CBD and THC display a distinctive affinity for the two human cannabinoids.

Specifically, CBD closely resembles 2-AG while THC displays striking similarities to anandamide.

While at first it was thought that CBD directly interacted with 2-AG and its CB2 receptors, more recent research suggests that CBD nudges instead our ECS to work better by making more efficient use of the existing human cannabinoids. In other words, CBD doesn’t increase the overall quantity of endocannabinoids in the system but helps the whole system work better.

As for THC, it seems to actively bind to the CB1 receptors, which are mainly located in the brain. This explains why THC affects our brain function much more than CBD. It is also the reason why most of THC’s adverse side effects, such as slow reaction times, psychosis, schizophrenia, and memory loss, are brain-related.

CBD and THC: their potential

CBD and THC have been widely studied over the past years. However, there are less THC studies due to its illegal status in most countries.

CBD has been studied for its anti-inflammatory, anti-anxiety, and anti-epileptic properties, among other qualities.

Due to its restricted and illegal status, there are fewer studies around THC. Some preliminary findings suggest that THC could be helpful with pain relief, glaucoma, nausea, insomnia, and lack of appetite.

CBD and its health possibilities

CBD mainly interacts with 2-AG and its respective receptors CB2. Because these are located in the gut and the immune system, CBD has shown potential in fighting pain and inflammation.

CBD appears to be particularly promising when it comes to auto-immune diseases such as arthritis, Crohn’s disease, and others because the immune system is heavily involved in these. In such conditions, the immune system overreacts and creates inflammation even though there is no cause for one.

In the case of arthritis, the inflammation happens around the joints, which become swollen and painful. With Crohn’s disease, the inflammation occurs in the lining of the gut. In both cases, CBD may prove a useful tool in managing inflammation and pain.

CBD also affects serotonin levels in the brain. Serotonin is a neurotransmitter that regulates mood and our sense of reward, among others. By interacting with serotonin, CBD might help manage depression and anxiety by rebalancing brain chemistry without the help of anti-depressants.

THC for health conditions

THC has its own potential benefits when it comes to helping our health.

Because it interacts with serotonin and dopamine in the brain, it directly affects how our brain functions. Just like CBD, THC can increase the levels of serotonin in the brain; low levels of serotonin have been linked with depression and anxiety. By balancing serotonin levels, THC may be able to help people suffering from anxiety and other mood disorders.

Similar to anandamide, dopamine has been called the ‘feel good’ neurotransmitter. Low levels of dopamine have been associated with low life pleasure, little enthusiasm for everyday activities, and lack of motivation. THC increases dopamine levels in the brain, thus helping the brain experience pleasure and reward. This is the reason why THC can make people feel euphoric and happy.

Serotonin and dopamine are also involved in the so-called vomiting brain centre. When this brain area is triggered, it sends the message to the stomach to expel any potentially harmful substances it contains. By stabilizing serotonin and dopamine, THC may help people suffering from nausea and vomiting.

THC has also been studied for its potential in pain management and relief. Research is focusing on how THC might help people with multiple sclerosis, HIV, and chronic pain.

THC may be helpful in the case of people suffering from anorexia as well. Even though research suggests that THC is not helpful with anorexia nervosa, it showed potential with patients suffering from HIV-induced anorexia and could be helpful with appetite stimulation of terminal cancer patients.

Finally, research on THC has also focused on its potential in helping with glaucoma which, if left untreated, can lead to blindness. THC has been found to lower intraocular pressure which could be particularly helpful with glaucoma and could prevent blindness. This is particularly interesting as research suggests that CBD may actually have the opposite effect, raising intraocular pressure, and is not recommended for glaucoma sufferers.

CBD and THC: the side effects

CBD has been classified by the World Health Organization as well-tolerated by the human body and non-addictive. The most common side effects are drowsiness, dry mouth, appetite changes, and diarrhoea. These side effects often subside by changing the dosage or the brand of CBD.

THC has far more significant side effects. These include memory loss, slower reaction times, red eyes, dry mouth, coordination problems (not being able to stand upright or walk in a straight line), psychotic episodes, and increased heart rate and blood pressure.

Interestingly enough, some studies suggest CBD may have the opposite effect, helping reduce heart rate and blood pressure.

A January 2020 report in the Journal of the American College of Cardiology reported that marijuana may be linked to coronary artery disease, heart disease, and chest pain. Smoking marijuana may carry some of the same risks as smoking tobacco.

A 2019 study in the Annals of Internal Medicine found an increase in marijuana-related visits to the emergency room of a Colorado, US, hospital after the state legalized recreational use of the drug. Most of these visits were associated with acute psychiatric symptoms.

There has been particular concern about teenagers experimenting with THC as teenagers with a predisposition for mental illness could develop schizophrenia when taking THC. It is still unknown why this occurs, and researchers are studying how THC affects the teenage brain. A possible explanation lies in the fact that the brain is still developing during the teenage years and THC directly affects the CB1 brain receptors. However, the exact mechanism for this eludes us at the moment.

Drug testing: CBD and THC

THC is detectable in urine, blood and saliva tests. CBD is not screened for most drug tests, hence unlikely to give a positive result.

Many people wonder whether taking CBD or THC could show up in a random drug test.

Drug test screen for THC and taking significant quantities of THC will show up in a drug test.

THC is detectable in urine for 3 to 30 days, in blood for up to a week, and in saliva for up to 3 days.

As for CBD, most drug tests do not screen for CBD. It is therefore highly unlikely that a drug test will test positive for CBD. However, and because the world of CBD is largely unregulated, consumers should be careful about the quality of CBD products they are purchasing. Although the legal threshold for THC content is 0.2% in the UK, research and random tests have shown that many CBD products contain THC levels beyond this threshold.

Frequent use of these products could lead to the build-up of THC traces in the body which could, potentially, be detectable with a drug test.

That is why CBD consumers should be careful and opt for reputable and trustworthy brands that run tests and display their Certificate of Analysis about their products. The Certificate of Analysis clearly discloses the levels of CBD, THC, and other cannabinoids and chemicals in their products.

Driving while taking CBD vs. THC

Common sense should prevail when driving. Although CBD does not cause any mental or physical incapacity, you should avoid driving if you feel unwell or drowsy.

The case for THC is more dangerous: feeling “high” means your reflexes and reaction times are delayed. This is highly perilous when driving and people taking THC should refrain from driving for several hours after taking THC.

CBD and THC: are they addictive?

The consensus is that CBD is not addictive nor has there been any CBD overdose. There has been no mention of people dying from CBD overdose nor is there any indication that people taking CBD became addicted to it, even after frequent daily consumption.

The case about THC is more complicated. While most THC users will not develop an addiction, some will.

Marijuana addiction displays common symptoms with other addictions like alcohol and nicotine:

  • Addicts require larger quantities of THC to reach the same level of “high” because they have developed a tolerance to THC.
  • Addicted THC users will spend more time looking for THC and will organize their everyday life around the use and consumption of THC.
  • When they run out of THC, addicted people feel frustrated and irritated and will go to great lengths to acquire their THC.
  • THC addicts deny their addiction and refuse to accept they have a problem. They perceive their habit as under control and will rebel against anyone telling them otherwise.
  • If THC addicts choose to fight their addiction, they may experience withdrawal symptoms such as mood swings, cravings, irritability, aggressiveness, insomnia, loss of appetite, and depression.

Researchers are still trying to understand how THC dependence occurs and what makes some people more at risk than others. Surprisingly enough, studies suggest that CBD may help fight THC addiction.

One interesting finding is that, the younger people are when they start taking THC, the higher the probability they will develop an addiction. This is particularly true for teenagers and people under 18. Just like the development of schizophrenia, this may have to do with the changes of the brain at this age and the way THC interacts with the CB1 brain receptors.


There are several kinds of CBD products: full-spectrum, broad-spectrum and CBD isolate.

CBD products are broadly classified into three categories: full-spectrum, broad-spectrum, and CBD isolate:

  • Industrial hemp contains more than 400 chemical compounds, of which CBD is the most common. Full-spectrum CBD contains CBD and all the other cannabinoids, terpenes, and flavonoids found in hemp. This means that full-spectrum CBD contains traces of THC—below the 0.2% threshold—as well as CBC, CBN, CBG, etc.
  • Broad-spectrum CBD is similar to full-spectrum CBD but without any trace of THC. In this case, full-spectrum CBD undergoes an extra extraction process to remove all traces of THC while leaving behind the other cannabinoids, flavonoids, and terpenes.
  • As the name suggests, CBD isolate contains 100% pure CBD and no other cannabinoids, flavonoids, or terpenes.

The entourage effect

The reason why people choose full-spectrum or broad-spectrum CBD as opposed to CBD isolate is what has been named the entourage effect.

Preliminary research suggests that, when all the natural compounds of hemp are consumed together, they increase each other’s potential, making the whole more than the sum of its parts.

Specifically, taking CBD with other cannabinoids, terpenes, and flavonoids may enhance each other’s efficiency and deliver an overall result that is superior to taking each compound independently. It’s as if these natural compounds boost each other.

People who want to benefit from the entourage effect but are wary of testing positive for THC usually opt for broad-spectrum CBD, which has no traces of THC but still all the other potentially beneficial compounds.

How does CBD interact with THC?

There has been some evidence of CBD lessening some of the adverse side effects of THC.

A 2006 study done by Ethan Russo suggests that CBD alleviates several of the side effects produced by THC, including drowsiness and hunger.

A 2015 study showed that CBD changes the affinity of the CB1 receptors to THC. It appears that CBD acts as a modulator of the CB1 receptor, thus mitigating the sense of “high” created by THC’s binding to these receptors.

More research is currently underway to better understand how CBD and THC behave synergistically and how they affect each other.

CBD, THC, and other medication

Both CBD and THC have the potential to interact with medications.

In particular, both CBD and THC interact with blood-thinning medication: it would appear that these cannabinoids change the metabolizing rate of the body and slow down how fast the liver metabolizes these medicines.

THC also interacts with medicine that lowers blood pressure, while both CBD and THC may affect how insulin is metabolized and used by the body. Both CBD and THC may improve the metabolizing of insulin, therefore, taking insulin with CBD or THC could excessively lower blood sugar levels.


While CBD consumption is legally sold in the UK as a food supplement, cannabis cultivation, THC production, and THC distribution are illegal unless there is a licence for them. Obtaining a licence can be difficult and only a handful have ever been issued.

The medical use of cannabis has been legalised in the UK since 2018. However, obtaining a prescription remains problematic. Consumers found in possession of cannabis or THC are fined £90.

THC has some potential health benefits. However, its psychotropic properties and side effects rightly trouble researchers and government institutions. Finding a way to take advantage of THC’s helpful features without the hallucinogenic side effects would be a great advance in the areas of health and wellbeing.

Until that happens, its significant side effects mean that THC is much more likely to make you sick than help. Consumers should steer away from THC unless a medical professional suggests otherwise.

Because CBD has been legal for longer, more research has been done on its health potential, suggesting CBD’s side effects are minor and its potential benefits great. However, and even though CBD may well make you feel better, you should consult your doctor before trying it as it may interact with your medication or health condition.

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