Travelling with medical cannabis as a UK patient requires careful planning....

https://city-wiki.win/index.php/Do_I_Have_to_Inform_the_Airline_That_I_Am_Carrying_Medical_Cannabis%3F_A_Guide_for_the_Anxious_Traveller

Travelling with medical cannabis as a UK patient requires careful planning. Just because your medication is legal at home does not mean it is permitted abroad. Rules across Europe vary wildly and local laws always take precedence