The mother of an 11-year-old boy with severe epilepsy fought for her son to be prescribed medical marijuana on the NHS.
Charlotte Caldwell explained how her son's condition - which saw him suffer 100 seizures per day at times - improved dramatically once he began taking the controversial medicine from the US.
She told ITV's This Morning: "As a mummy, if you're placed in that situation, where your little boy is continuously having life-threatening seizures in front of you, you will do anything in your power to stop that happening and take it away."
When Billy ran out of the drug, originally prescribed by US specialists, a doctor in Northern Ireland prescribed him more on the NHS.
It is believed to be the first time that a patient has been prescribed the drug by an NHS doctor.
CBD products don’t contain any THC, the chemical in cannabis which causes the high – and it is legal in the UK.
Charlotte, who is Billy's full-time carer, added: "It's two little bottles of oil. One is a CBD which is really good quality whole plant extract - no synthetics, no chemicals.
"And the other bottle is a THCA, which is the part that the controversy is about in our country - 0.2 is the legal limit but this is slightly over that level.
"It's working for him. Billy is just over 90 days seizure-free today.
"To me, that's incredible because one seizure can kill him. And to find a medicine that is natural... it's 100% regulated [in the US]."