This article explains how medical cannabis can be prescribed for chronic...

https://andreimgc701.cavandoragh.org/is-medical-cannabis-actually-legal-in-the-uk-or-is-that-just-marketing

This article explains how medical cannabis can be prescribed for chronic conditions in the UK. Access is through a specialist doctor, with NHS prescriptions being uncommon. The choice of product is guided by the clinician based on individual needs