Tens of thousands of children and young people across the UK suffer from severe forms of epilepsy which are resistant to treatment.
For those with intractable epilepsy the options for treatment are limited and the risk of a catastrophic seizure is very real.
But a growing body of evidence has pointed to cannabis having a positive effect on preventing seizures even in people who don't respond to other drugs.
In 2018, medicinal cannabis was legalised following a high profile campaign led by parents of children with intractable epilepsy.
They hoped the change in the law would lead to the drug becoming widely available on the NHS.
But more than six years later File on 4 Investigates has discovered families going to extreme lengths to access a drug they say is keeping their children alive.
Reporter Alastair Fee meets families who claim they have been forced to give their children illegal cannabis sourced online and follows others who regularly break the law importing medicine from the Netherlands.