What evidence is there for medical cannabis?

Legal medicinal cannabis has become increasingly popular in recent years as a remedy for those dealing with chronic pain. It offers an alternative to prescription pain killers and their adverse side effects, such as prolonged constipation, nausea and drowsiness. There are now various medically approved and distributed cannabis-based medicines being prescribed for illnesses that lead to severe pain.

What is medical cannabis?

First, we need to cover what medicinal cannabis is. In an umbrella term, medicinal cannabis is any cannabis-based medicine used to treat the symptoms of pain. These medicines contain specific parts of the cannabis plant. The two main natural chemicals that occur in this plant are cannabidiol (CBD) and tetrahydrocannabinol (THC).

These two chemicals are used in alternative medicine to treat a variety of illnesses associated with chronic pain. But what evidence is there to the effectiveness of legal medicinal cannabis? How does it compete with the world of traditional medicine?

Medicinal cannabis for Epilepsy

Medical cannabis is currently being used to treat some forms of epilepsy, as early evidence from studies has suggested CBD is effective in controlling epileptic seizures. This belief is further promoted by the fact that the UK has now approved a cannabis-based treatment called Epidyolex. This medicine is made of pure CBD, and clinical trials have shown Epidyolex could reduce the number of seizures a person has by up to 40%. However, Epidyolex is currently only available as a treatment option for more severe cases of epilepsy.

Medicinal cannabis for Multiple Sclerosis

The condition of multiple sclerosis or ‘MS’ can lead to severe muscle stiffness and spasms. Once again, medicinal cannabis has been utilised in this case to provide an alternative form of pain relief. Sativex is a mouth spray that contains a mixture of both CBD and THC. The effectiveness of Sativex is regularly debated and is not considered to work for everyone. This being said, with those who use it around 7 out of 10 see a reduction in muscle spasms of about 20%. Sativex has also been found to help ease other symptoms of MS, such as bladder problems.

Medicinal cannabis for the effects of Chemotherapy

Used to treat a range of cancers, chemotherapy treatment can leave patients with severe sickness and nausea as a byproduct of the radiation being used to kill the cancerous cells. As a method to combat this, the drug Nabilone was created from legal medicinal cannabis. In one study of 60 patients, 75 % said they found Nabilone to be more effective in treating their nausea than the traditional alternative (prochlorperazine).


The world of legal medicinal cannabis is still relatively in its infancy stage, with many more avenues to explore. However, what cannot be denied is the hopefulness that the findings of these studies have already brought. That combined with the introduction of cannabis-based prescriptions on the NHS suggest there is evidence for the effectiveness of medicinal cannabis, and that this will only continue to develop in the future.