Cannabinoids are natural compounds found in the Cannabis sativa plant, with over 400 chemical substances identified. More than 100 of them are cannabinoid compounds. The most well known are tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD). The main difference between the two is that THC has strong psychoactive effects and causes a person to feel high, whereas CBD is non-psychoactive.
Cannabinoids derived from hemp plants are legal in the UK and can be found in stores and online. However, some cannabinoids are controlled substances and are not legal to possess or supply in the UK.
The Endocannabinoid System
The endocannabinoid system (ECS) is a neuromodulatory system that plays a role in regulating sleep, mood, memory, appetite, and reproduction. Even if you do not use cannabis, the ECS is still active in the body. The endocannabinoid system consists of cannabinoid receptors, endocannabinoids, and the enzymes responsible for their synthesis and degradation.
Endocannabinoids are similar to cannabinoids, but they are molecules made by your body. Endocannabinoid receptors are found throughout the body, called CB1 and CB2 receptors. CB1 receptors are mostly found in the nervous system while CB2 receptors are mostly found in the peripheral nervous system.
Endocannabinoids bind to either of these receptors to signal that the ECS needs to take action. Enzymes are responsible for breaking down the endocannabinoids.
Types of Cannabinoids
Most people are familiar with the two most common cannabinoids: THC and CBD. But cannabis plants can actually produce more than 100 cannabinoids. Here are some of the others that researchers are studying:
- Cannabinol (CBN). A mildly psychoactive cannabinoid, though significantly less potent than THC.
- Cannabichromene (CBC). A non-psychoactive cannabinoid found in the cannabis plant. Research into its properties is ongoing.
- Cannabigerol (CBG). A non-psychoactive cannabinoid sometimes called the "mother cannabinoid" as other cannabinoids are derived from it. Research is at an early stage.
- Tetrahydrocannabinolic acid (THCA). An acidic precursor to THC, present in raw cannabis before it is dried or heated. It is not psychoactive in its natural state.
- Tetrahydrocannabivarin (THCV). A cannabinoid structurally similar to THC that is the subject of ongoing research.
- Cannabidivarin (CBDV). A non-psychoactive cannabinoid related to CBD that is the subject of ongoing research.
What do cannabinoids do?
The two main cannabinoids, THC and CBD, are chemically similar to the body's endocannabinoids. This allows them to interact with the cannabinoid receptors. This interaction affects the release of neurotransmitters in the brain.
THC binds with the CB1 receptors in the brain and produces psychoactive effects. CBD interacts with the endocannabinoid system differently and does not produce a high. Research into the specific effects of individual cannabinoids is ongoing.
Effects of cannabinoids
THC and CBD have different side effect profiles. THC may cause:
- Increased heart rate
- Dry mouth
- Coordination problems
- Anxiety
- Memory impairment
CBD side effects may include:
- Fatigue
- Diarrhoea
- Changes in appetite or weight
Do cannabinoids make you feel high?
Some cannabinoids will make you feel high. THC, the main psychoactive compound in cannabis, stimulates the part of the brain that responds to pleasure via the dopamine system, producing a relaxed or euphoric feeling. CBD does not produce these effects and is non-intoxicating.
Taking high doses of cannabis can sometimes cause anxiety and paranoia. Not everyone's experience with cannabis is the same.
What cannabinoids show up on a drug test?
THC shows up on drug tests. When cannabis is used, THC can remain detectable in the body beyond the period when its effects are felt. The amount consumed can also affect how long it remains detectable. Depending on the type of test used, THC may be detectable the same day a person uses it or up to three months later.
Tests typically look for THC metabolites rather than THC itself. Cannabis use may be detected by urine, hair, blood, saliva, or sweat tests. CBD products sold legally in the UK contain no more than 1mg of THC per container, but if you are subject to drug testing, speak to your employer before using any CBD product.
What is Cannabinoid Hyperemesis Syndrome?
Cannabinoid hyperemesis syndrome (CHS) is a condition that leads to severe and repeated bouts of vomiting. Other symptoms include nausea, dehydration, and abdominal pain. It is a rare condition associated with long-term daily cannabis use.
THC binds to molecules in both the brain and the digestive tract. Long-term cannabis use can change the way these receptors respond, which may lead to the symptoms of CHS.
If you use cannabis and experience severe repeated nausea, vomiting, and abdominal pain, speak to your GP. The known way to resolve CHS is to stop cannabis use entirely. Medical care may be needed for severe dehydration.