You have probably come across many names for cannabis, including marijuana, hemp, pot, grass and hash. Cannabis has been used by people for thousands of years, both medicinally and recreationally.

The cannabis plant produces a resin that contains various substances. Some of these may have medicinal value. These substances are known as cannabinoids.

Two main cannabinoids have been identified:

- delta-9-tetrahydrocannabidiol (THC) – it is illegal to use this substance in the UK

- cannabidiol (CBD) – this is legal in the UK.

There are some drugs available that are derived from cannabis. For example Sativex is used for multiple sclerosis and Nabilone, but it is also sometimes used for sickness caused by chemotherapy. Drugs like this go through the same processes as any other medicine to be licensed in the UK as a prescribable drug.

Cannabis and cancer

There has been a lot of interest in cannabinoids. Delta-9-tetrahydrocannabidiol and cannabidiol have been studied to see if they could have any role in the treatment of cancer.

Most of the scientific research has been done in a laboratory. Scientists have found that different cannabinoids can:

- cause a cell to die

- stop cells from dividing

- stop cells from developing new blood vessels.

But they have also found that cannabinoids can:

- damage important blood vessels

- in some situations, encourage cancer cells to grow.

Some studies have looked at whether using cannabis may increase the risk of developing cancer. These have produced different results. Some research has shown that using cannabis may protect against cancer. But other studies have shown an increased risk of cancer.

It is still unclear whether using cannabis has any anti-cancer effects. But there is some evidence that the chemicals in cannabis might help with symptoms such as nausea and pain. For example, some drugs that have been developed using the chemicals in cannabis have been effective in treating sickness caused by chemotherapy, or improving a person’s appetite. But these studies have had mixed results when used in clinical trials. Because of the mixed results, the general feeling of experts is that there needs to be more research into the chemicals found in cannabis and their possible benefit.

Cannabis oil

Cannabis, particularly cannabis oil, is a popular topic. Understandably, many people want to try anything that may help treat cancer – particularly if things are not going well with conventional treatments. Cannabis oil is only one of a number of treatments people might come across. Cannabis oil can contain varying amounts of CBD and THC.

If you are thinking about using cannabis oil, there are some important things to keep in mind:

Buying it online can be risky. One reason for this is because you do not know what you are getting. For example, you are not sure how pure it is.

There are side effects of using cannabis oil. THC can increase your heart rate, cause dizziness, hallucinations, paranoia and make you feel ‘stoned’. They may also interact with other drugs.
The cannabinoid delta-9-tetrahydrocannabidiol (THC) and products that contain THC are illegal in the UK.

CBD oil

CBD in its pure form is not a controlled substance under the Misuse of Drugs Act.

CBD oil does not contain THC and therefore does not have any psychoactive effects. It can be sold in the UK as long as it is sold as a food supplement and the sellers are not making any claim about its medicinal properties.

There are a number of examples where people say that using CBD oil has had a dramatic effect on their health. But these are individual stories and not based on clinical research trials. If you are thinking of using CBD oil, we suggest you talk to your healthcare team.