In the UK, medical cannabis prescriptions start with a specialist assessment...

https://romeo-wiki.win/index.php/Do_I_Need_a_Referral_to_See_a_Specialist_for_Medical_Cannabis_in_the_UK%3F

In the UK, medical cannabis prescriptions start with a specialist assessment usually through private clinics, as NHS prescriptions are rare. If approved, treatment is supplied by regulated pharmacies to ensure safety