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

https://wiki-aero.win/index.php/How_to_explain_to_family_that_you_cannot_bring_your_medical_cannabis_on_a_trip

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