Whenever I’ve gone abroad I’ve never really taken anything just put all my stuff in my hand luggage , I know some people do get a note from their doctor , before my hand luggage goes through the x ray thingy I normally tell them about the insulin which they can see , same thing when I empty my pockets etc as I always carry my pen in my pocket , never had a problem .In fact on a trip back from Lanzarote the guy on security said to me before I explained , insulin ??. I said yes no problem encountered