What exactly is cannabis oil?

It’s not addictive and you can’t get high from it, and yet the market for cannabis oil is booming in the UK. Several high-profile stories purporting to extol its medicinal benefits have hit the headlines of late further adding to its popularity. So, what exactly is cannabis oil? Well firstly, the name is misleading. It’s not cannabis oil that is for sale legally in the UK.

Cannabis oil is extracted from the cannabis plant using solvents. This can be done by traditional solvent extraction, or more likely these days, supercritical CO₂ extraction. Together with the flower (marijuana) and resin (hashish), it is one of the three main forms of cannabis products. The psychoactive component of the cannabis drug is Δ⁹-tetrahydrocannabinol (THC), which gives users the ‘high’ feeling. As a central nervous stimulant, THC can alter mood and sensory perceptions. The United Nations Office on Drugs and Crime (UNODC) states that cannabis often contains 5% THC content and resin can contain up to 20% THC content. Cannabis oil can be the most potent of the main cannabis products because of its high level of psychoactive compounds per volume. This can vary up to 98% THC content. Other names for cannabis oil include marijuana oil, Rick Simpson Oil (RSO), Full extract cannabis oil (FECO), hash oil, dabs, shatter and wax. This potent cannabis oil cannot be sold legally in the UK. To unravel this confusion, we need to look at the plant’s history.

Hemp vs. marijuana

Ancient cultivators of the cannabis sativa plant realised that it had two main properties over 10,000 years ago. When the flower buds were discovered to have psychoactive effects, cultivators began separating the plants to isolate their ‘medicinal’ characteristics: these plants closely resemble today’s marijuana plants. The other variety of the plant was bred to be tall and durable and became what we now call industrial hemp. The industrial hemp plants tend to produce high levels of cannabinoid (CBD), while producing low amounts of THC. Conversely, the marijuana plant produces high THC levels and low CBD levels. So, both hemp and marijuana come from the same plant, but they are very different.

CBD is closely related to THC but has quite different pharmacological effects. Unlike THC, CBD is not psychoactive. This means that it does not change the state of mind of the person who uses it. However, it does appear to produce significant changes in the body and has been found to have medical benefits. As well as being beneficial for treating a number of ailments, it can promote sleep, boost appetite and reduce stress, anxiety and depression.

It’s actually CBD (or hemp) oil

Cannabis oil is illegal to possess, supply or use; whereas CBD is now recognised as a medicine following scientific studies into its use. CBD oil is therefore legal in the UK. As such, the cannabis oil that is for sale in the UK is actually CBD oil, which is made from approved strains of industrial hemp.

In UK law, you cannot sell a product in the UK with more than 1 mg of any controlled substance (such as THC). To sell CBD products they are legally required to contain less than 0.05% THC. However, it is generally agreed that the authorities will ignore THC content of up to around 0.2% if imported from Europe, according to the Cannabis Trades Association UK (CTA UK).

CTA UK represents around 90% of the hemp and cannabis industry to promote good practice, provide practical advice and ensure consumers of legal cannabis and hemp products have access to quality information. Its research shows that there are approximately 300,000 users of CBD oil and the market is growing month on month. There are around 1500 new users each month, which results in around a 500-net-user gain each month. Apparently, many people are keen to try the oil but don’t stick with it because the effects are not often apparent immediately. The oil is usually bottled with a dropper to be consumed orally and has a very distinct taste.

The UK market is now approaching £50 million a year with over 1800 sellers. CTA UK sees an average of 10 new applications each week for companies wanting to sell CBD. Holland & Barrett have been selling CBD oil for more than 2 years and their sales account for 10% of the market share. The health food shop sells a range of hemp oil and CBD oil as capsules, drops, shampoos, conditioners, hand cream, deodorant, eye serum, lip balms and body lotions. As well as being taken orally for medicinal use, it can be applied cosmetically to the surface of the skin and its benefits are said to include preventing signs of ageing and protecting against eczema and psoriasis. CBD hemp-infused water was launched in UK shops in March. According to CTA UK, around 68% of CBD users are female and 32% are male.

What are the effects of THC and CBD?

Cannabinoids attach themselves to certain receptors in the body to produce their effects. The human body has two receptors called cannabinoids receptor type 1 (CB1 receptor) and type 2 (CB2 receptor). CB1 receptors are found all around the body, but many are concentrated in the brain. The CB1 receptors in the brain deal with coordination and movement, pain, emotions and mood, thinking, appetite and memories, among others. THC attaches to these receptors. CB2 receptors are more common in the immune system and affect inflammation and pain.

CBD also affects the CB1 and CB2 receptors, but not directly. In the brain, CBD stimulates several tertiary receptors in the endocannabinoid system. These include the adenosine receptor (which can help with bone and heart health), serotonin receptors (which can help regulate mood) and the capsaicin receptor (which is the same receptor that spicy food stimulates). As such, it helps regulate body temperature, inflammation and pain management.

Cannabis tests

There is also evidence and some scientific studies that suggest CBD can help people with epilepsy manage their seizures. CBD oil is also used to ease the symptoms of multiple ­sclerosis, Parkinson’s disease, joint pain, anxiety and depression, along with a range of other conditions.

One study also suggests that CBD can help manage addictions, specifically nicotine. Smokers who used a CBD inhaler smoked 40% fewer cigarettes compared to a control group. The study’s authors point to the CB1 receptors’ role in rewarding addictive behaviour and say that CBD has shown promising results in animal-addiction studies for more powerful drugs like methamphetamine.

Orthopaedic surgeons have also reported some of their patients self-treat for their arthritis with a CBD tincture or topical preparation, but there is little research investigating this.

There is evidence to support the idea that medical marijuana (containing THC) can alleviate some of the side-effects of cancer including nausea during chemotherapy. Some users have claimed to find similar benefits from using CBD oil, although this has never been scientifically proved.

Despite the UK being the world’s largest producer and exporter of legal cannabis for medical and scientific use, the UK government maintains that cannabis has no medical use. Almost all of the UK’s legal cannabis production goes towards a medicine called Sativex® (nabiximols), produced by GW Pharmaceuticals. Sativex® is a mouth spray consisting of a formulated extract of the cannabis sativa plant that contains both THC and CBD in a 1:1 ratio. It was developed as a treatment for the relief of symptoms in patients with moderate-to-severe spasticity due to multiple sclerosis (MS).

The Home Office has recently announced it is considering a medical cannabis trial for the treatment of epilepsy. The move follows a petition of more than 30,000 signatures set up after a family sought cannabis oil in The Netherlands to alleviate symptoms in their 6-year-old child.

Sir Mike Penning, Conservative MP for Hemel Hempstead, has urged Home Office Ministers to grant the licence immediately. He said in his view there was: “substantial scientific evidence showing that cannabis is a harmful drug and, in its street form, is a gateway drug for many users. But surely in the 21st century, we can find an acceptable way to separate the two so that patients who gain relief from the use of the drug are legally and safely able to do so whilst recreational use is still restricted”.

Last reviewed: 29/09/2023