The UK has authorised the use of the world's first prescription cannabis medicine.
GW Pharmaceuticals launched its product, named Satiyex, earlier this week (June 22nd).
The treatment can be used to help people to cope with symptoms of spasticity due to Multiple Sclerosis (MS).
Ed Holloway, head of care and services research at the MS Society, said that the society was "really delighted" with the decision to grant the product full regulatory authorisation.
Mr Holloway added: "There is unfortunately no cure for MS and very few effective therapies.
"This has potential to make a real difference to people's quality of life who are experiencing spasticity."
There are around 100,000 people in the UK suffering with MS, according to the group.
Damage to the protective sheath surrounding nerve fibres in the body is behind the disease.
The sheath, known as myelin, can interfere with messages between the brain and the rest of the body when it is damaged.