Introduction to cannabinoids
Cannabinoids are a group of active compounds found in the cannabis plant. These naturally occurring substances are responsible for many of the effects of cannabis, from the psychoactive high associated with THC to the calming and pain-relieving effects attributed to CBD.
Over the past few decades, there has been a growing interest in the study of cannabinoids and their potential therapeutic uses. This interest has been fuelled by changes in societal attitudes towards cannabis, advancements in our understanding of the human body's endocannabinoid system, and anecdotal evidence of the benefits of cannabinoids for a variety of health conditions.
The science of cannabinoids
To understand cannabinoids, one must first understand the endocannabinoid system. This complex cell-signalling system was discovered in the late 1980s and early 1990s by researchers exploring how THC, a well-known cannabinoid, works. The endocannabinoid system is active in your body even if you do not use cannabis and plays a crucial role in maintaining homeostasis, or internal stability, in response to changes in the environment.
It has been documented in research studies that cannabinoids interact with the body's endocannabinoid system (ECS), which is found in the nervous system and throughout the body, mainly through two types of receptors: CB1 receptors, which are mostly found in the central nervous system, and CB2 receptors, which are more often found in peripheral cells associated with the immune system.
When cannabinoids bind to these receptors, they influence the release of neurotransmitters in the brain, leading to various physiological effects.
Cannabinoids can enter the body through inhalation, ingestion, or topical application, and their pharmacokinetics can vary depending on the method of consumption. The effects of cannabinoids can also vary depending on the specific cannabinoid and the method of consumption.
There are three main types of cannabinoids:
| Type of cannabinoid | Description |
|---|---|
| Phytocannabinoids |
These are found in the cannabis plant and a handful of other plants. Cannabis represents the most abundant and diverse source of phytocannabinoids, or plant cannabinoids on the planet. More than 150 different cannabinoids are found in the cannabis plant. However, the cannabis plant produces most of its cannabinoids in acid form, such as THCA and CBDA. These acidic cannabinoids convert into the more familiar neutral forms, such as THC and CBD, through decarboxylation, which happens during storage or when they are heated. |
| Endocannabinoids |
These are produced by different organs and tissues in the body. They are derived from arachidonic acid and differ in chemical structure from the cannabinoids found in cannabis, but they act on the same cannabinoid receptors. The body can synthesise endocannabinoids to help regulate processes as diverse as pain, memory, mood, immunity, sleep, and responses to stress. The two main endocannabinoids are anandamide (AEA) and 2-AG (2-arachidonoylglycerol). |
| Synthetic cannabinoids |
These compounds do not occur naturally in plants or people but are synthesised using chemical processes. There are more than 200 synthetic cannabinoids, nearly all of which are designed to exert powerful effects on the body’s cannabinoid receptors. However, the safety of certain synthetic cannabinoids is questionable as they can have detrimental effects on consumers. |
The most common cannabinoids
The most well-known and researched cannabinoids are THC (delta-9-tetrahydrocannabinol) and CBD (cannabidiol).
THC is the primary psychoactive compound in cannabis, responsible for the "high" that users experience. It can induce feelings of euphoria and relaxation, alter sensory perception, and impair short-term memory. However, THC also has potential therapeutic effects, such as pain relief, reduction of nausea and vomiting, and stimulation of appetite.
On the other hand, CBD is non-psychoactive and has been the subject of much research due to its potential therapeutic effects. A purified CBD medicine is approved for seizures associated with certain rare forms of epilepsy, and CBD has also been studied for possible anti-inflammatory, pain-relieving and anti-anxiety effects, mostly in laboratory, animal or small human studies. It has been suggested that CBD can counteract some effects of THC, such as anxiety or paranoia, but a 2023 randomised trial in 46 healthy volunteers found no evidence that CBD, at the CBD:THC ratios most common in cannabis products, protected against the acute adverse effects of THC.
Other notable cannabinoids include cannabigerol (CBG), cannabichromene (CBC), and tetrahydrocannabivarin (THCV), each with its unique effects and potential therapeutic benefits.
See the full overview of the most common cannabinoids in the table below.
The potential therapeutic effects of cannabinoids
Researchers have investigated a wide range of potential health benefits of cannabinoids. The evidence is strongest for a small number of uses, such as chronic pain, chemotherapy-induced nausea and vomiting, and seizures in certain rare forms of epilepsy, while many other potential effects have so far been shown mainly in laboratory or animal studies.
Chronic pain is one of the most studied uses of cannabinoids. Studies suggest that cannabinoids may relieve some types of chronic pain by interacting with cannabinoid receptors in the body's pain control system. This has led to the use of medical cannabis in conditions such as arthritis, fibromyalgia, endometriosis, and more.
| Cannabinoid short name | Full name | Description and potential therapeutic effect | |
|---|---|---|---|
| THC | Tetrahydrocannabinol | Tetrahydrocannabinol, or THC, is the most well-known and most often the most prevalent cannabinoid found in cannabis. It has been studied for pain, nausea, appetite and sleep. A 2017 US National Academies review rated the evidence as substantial for cannabis in chronic pain in adults and conclusive for cannabinoid medicines in chemotherapy-induced nausea and vomiting, but as limited for increasing appetite in people with HIV/AIDS and insufficient for relieving symptoms of conditions such as ALS. | Read article |
| CBD | Cannabidiol | Cannabidiol, or CBD, is the non-psychoactive cannabinoid best known for a purified CBD medicine approved for seizures associated with Lennox-Gastaut syndrome and Dravet syndrome, while a medicine combining THC and CBD is used for muscle spasticity in multiple sclerosis. It has been studied for anxiety and sleep problems, but the evidence for these uses is limited. In mouse studies, THC and CBD given together reduced the growth of glioma tumours, but this has not been shown in people. | |
| CBG | Cannabigerol | Cannabigerol, or CBG, is a non-psychoactive cannabinoid that has been studied for possible effects on inflammation, pain and nausea. In mouse studies it reduced experimental colitis and the growth of colon cancer cells, but it has not been shown to treat inflammatory bowel disease, Crohn’s disease or cancer in people, and research on CBG remains limited. | |
| CBC | Cannabichromene | Cannabichromene, or CBC, is a non-psychoactive cannabinoid. In a laboratory study, CBC increased the viability of mouse neural stem/progenitor cells during differentiation, and cell studies have examined its anti-tumour activity, although it was less potent than CBD in one comparison. These effects have not been shown in people. | Read article |
| THCV | Tetrahydrocannabivarin | Tetrahydrocannabivarin, or THCV, is structurally similar to THC and is often described as psychoactive, but researchers note that at the doses studied it has distinct effects, including blocking rather than activating CB1 receptors, and should not be classed as an intoxicating analogue of THC. Claims that it relieves stress or prevents anxiety and panic attacks have not been established. In animal models of Parkinson’s disease it showed neuroprotective and symptom-relieving effects, but it has not been shown to treat Alzheimer’s disease, Parkinson’s disease or multiple sclerosis in people. | |
| THCA | Tetrahydrocannabinolic acid | Tetrahydrocannabinolic acid (THCA) is the non-psychoactive acidic precursor of THC and can represent up to 90% of the total THC in the plant; it converts to THC when heated. Laboratory and animal studies suggest possible anti-inflammatory and neuroprotective properties, for example in a mouse model related to Huntington’s disease, but it has not been shown to treat arthritis, seizures, multiple sclerosis, Alzheimer’s or Parkinson’s disease in people. | |
| CBN | Cannabinol | Cannabinol, or CBN, is a cannabinoid formed mainly as THC ages, and evidence on whether it produces cannabis-like effects in humans is mixed. It is often marketed as a sleep aid, but a 2021 review found insufficient evidence to support sleep-related claims. Laboratory research has suggested possible pain-relieving and anti-inflammatory effects, but benefits for conditions such as arthritis or Crohn’s disease have not been established in people. | |
| CBDV | Cannabidivarin | Cannabidivarin (CBDV) is a non-psychoactive cannabinoid that reduced seizures in several rodent seizure models. However, in a 2018 placebo-controlled trial in 162 adults with focal seizures, a CBDV-based medicine did not reduce seizures more than placebo. A rat study suggested possible anti-nausea potential, and its effects on inflammation, pain and mood disorders have not been established in people. | Read article |
| CBDA | Cannabidiolic acid | Cannabidiolic acid (CBDA) is a non-psychoactive cannabinoid that is the acidic precursor to CBD. In animal studies it reduced nausea and vomiting, and in a laboratory study it inhibited the migration of breast cancer cells. It may also have anti-inflammatory and anti-anxiety potential, but more research is needed in these areas. | |
| CBGA | Cannabigerolic acid | Cannabigerolic acid (CBGA) is the precursor from which the cannabis plant makes THCA, CBDA and CBCA, the acid forms of THC, CBD and CBC. It is often referred to as the "stem cell" of cannabinoids. Anti-inflammatory, analgesic and anti-fungal properties have been suggested, but research is at an early stage. | |
| Δ8-THC | Delta-8-tetrahydrocannabinol | Delta-8-tetrahydrocannabinol (Δ8-THC) is a psychoactive cannabinoid with pharmacology very similar to, but less potent than, its more common counterpart, Δ9-THC. Anti-nausea, anti-anxiety, appetite-stimulating, pain-relieving and neuroprotective properties have been suggested, but research, particularly in humans, is limited. | |
| CBL | Cannabicyclol | Cannabicyclol (CBL) is a non-psychoactive cannabinoid that is found in low concentrations in most cannabis strains. It is believed to have anti-inflammatory properties, but more research is needed to fully understand its potential therapeutic benefits. | |
| CBE | Cannabielsoin | Cannabielsoin (CBE) is a little-known cannabinoid and there is currently not much known about its potential therapeutic benefits. More research is needed to understand this cannabinoid. | |
| CBCV | Cannabichromevarin | Cannabichromevarin (CBCV) is a non-psychoactive cannabinoid that is the varin version of CBC. It is believed to have potential therapeutic benefits, but more research is needed to fully understand its effects. | |
| CBNA | Cannabinolic acid | Cannabinolic acid (CBNA) is a non-psychoactive cannabinoid that is the acidic precursor to CBN. It is believed to have potential therapeutic benefits, but more research is needed to fully understand its effects. |
Research has also suggested that cannabinoids may have anti-inflammatory effects, which could be beneficial for conditions such as Crohn's disease, inflammatory bowel disease, and rheumatoid arthritis. Additionally, cannabinoids have been studied for their potential anti-anxiety effects, but a 2017 US National Academies review found only limited evidence that CBD improved anxiety symptoms in people with social anxiety disorder, and a 2019 systematic review found scarce evidence that cannabinoids improve anxiety disorders.
Cannabinoids have also been explored for their potential role in cancer treatment. While research is still in the early stages, laboratory and animal studies have suggested that cannabinoids may slow the growth of cancer cells, although there is insufficient evidence that they are an effective cancer treatment in people. Cannabinoids have also been studied for cancer-related pain, and THC-based medicines are approved for nausea and vomiting caused by chemotherapy.
It is important to note that while the potential therapeutic effects of cannabinoids are promising, more research is needed to fully understand their benefits and risks. As with any treatment, the effectiveness of cannabinoids can vary from person to person, and they may not be suitable or safe for everyone. Always consult with a healthcare provider before starting any new treatment.
