THC cannabis plant

What is THC (Tetrahydrocannabinol)?

Of all the cannabinoids found within the cannabis plant – and there are 113 of these chemical compounds that could potentially have a myriad of well-being benefits for humans – two have become exceptionally famous in recent years. Of course, we’re talking about THC and CBD. The CBD market continues to grow at a phenomenal rate in the UK, but surprisingly, many of us are still unclear what the difference between CBD and THC is. So, what exactly is the cannabis compound that causes euphoria in humans? How does it work; how does it compare to CBD and is it even legal in the UK? In this post, we’ll take a closer look at the fascinating particulars of THC.

What is THC?

THC is an acronym for tetrahydrocannabinol, a phytocannabinoid found within the Cannabis sativa plant species. It is most concentrated within the marijuana plant, particularly in a resin that is secreted by glands surrounding the plant’s reproductive organs. THC is the chemical compound of cannabis that is responsible for most of its psychological effects. When eaten, smoked or vaporised, THC interacts with receptors located in the hippocampus, cerebellum and amygdala. These are areas of the brain that are responsible for memory, coordination, thinking and pleasure, and THC interaction with associated receptors can have a significant influence on these vital functions.  

How Does THC Get You High?

To understand how THC has psychoactive effects, we must first explore the biochemistry of our endogenous cannabinoid system.

The endocannabinoid system is a complex system within our bodies that regulates memory, cognition, time perception, mood and sensory perception.  Endocannabinoids and their receptors are located throughout the body within our organs, brain, connective tissue and cells. The endocannabinoid system undertakes different tasks in each tissue type, but the overall goal is homeostasis – a stable internal environment regardless of the external environment.

Endocannabinoids are compounds that encourage homeostasis by binding to CB1 and CB2 receptors, enabling communication between different cell types. THC, a phytocannabinoid, works similarly to the body’s endocannabinoids by binding to receptors. THC can “over-activate” the functions that are regulated by the endocannabinoid system (sleep, mood, cognition, etc.). Ultimately, this is the euphoric feeling that is experienced after the consumption of THC.


Both THC and CBD (cannabidiol) are prominent cannabinoids of the cannabis plant. But what’s the difference between the two?

Marijuana and hemp both produce THC and CBD, but marijuana has a higher concentration of THC, whereas hemp has a higher concentration of CBD. The cannabinoids are identical in terms of chemical makeup but differ in their chemical arrangement. This means that they are received differently by the body as the cannabinoids interact with endocannabinoid receptors. It is believed that THC is capable of binding to CB1 and CB2 receptors but CBD only stimulates them. CBD offers similar wellness benefits to THC, minus the psychoactive effects. CBD is legal in the UK whereas THC (cannabis) is defined as a Class B drug and remains illegal for recreational use.

Medicinal Uses of THC

Medicinal use of the cannabis plant dates back thousands of years. There are various ways to administer cannabis including edibles, vaporising, oils and tinctures and capsules. Medical cannabis is an umbrella term that covers many cannabis-derived products including CBD and Delta-9 THC that are used to relieve symptoms.

Some cannabis-derived products are available as medicinal cannabis on prescription in the UK. According to NHS England, medical cannabis is only prescribed in certain circumstances, which include those with severe types of epilepsy, adults experiencing nausea and vomiting as a result of chemotherapy or people with spasms and muscle pain due to multiple sclerosis. Medical cannabis will also only be prescribed if alternative treatments have not worked.

Medicinal benefits of THC can include:

  • Pain control
  • Muscle relaxant
  • Reduction of tremors
  • Ease nausea
  • Weight loss

To understand the full extent of the benefits of medicinal cannabis, further human studies are required. 

Side Effects

Some side effects are specific to the THC cannabinoid; these can be serious and are associated with the compound’s psychoactive properties. These include an elevated heart rate, dry mouth, reduced reaction time, loss of memory and issues with coordination. In the event of overconsumption of THC, there is a risk of paranoia and anxiety, particularly if tolerance is low, and the psychoactive effects can be overwhelming. 

CBD, on the other hand, rarely exhibits significant side effects even if taken in a large dose.

It is tolerated well and generally regarded as very safe to use.

UK Legislation

Cannabis in the UK is classified as a Class B drug and remains illegal for recreational use. Medical cannabis use became legal in 2018, providing it is prescribed by a registered specialist doctor.

CBD oils and CBD-based products are legal in the UK, as long they contain less than 0.2% THC. You will find these on the shelves of many wellness shops and they are available to buy online. When purchasing CBD products, look for high-quality products and check that the brand provides lab reports which highlight the content of THC and additional cannabinoids and terpenes

Final Thoughts

THC is a similar compound to CBD and both are derived from the cannabis plant species. However, the two cannabinoids have distinct properties that separate them from each other; the key difference being the intoxicating effects of THC which CBD does not possess. CBD is better known for its wellness benefits without serious side effects, and it can even counteract some of the unpleasant side effects that can arise from THC consumption. THC also remains an illegal substance in the UK, except for instances where it is prescribed for medicinal use by a registered doctor.

If you are interested in experiencing the wellness effects of cannabinoids, look for high-quality CBD products that contain less than the legal limit of 0.2% THC. Always check with your doctor if you are already taking prescription medication.


The world is rapidly waking up to the power of CBD. With millions of people now using CBD it’s more important than ever to share our experiences. Looking at our most popular products is a great way to get an insight into the essentials people are adopting as part of their daily routines.