My wife also travels with medication for MS. Whenever we travel she obtains a letter from the medication provider explaining her circumstances. This letter letter specifically states the injections must be taken as cabin baggage, and provides a 24 hour helpline for use if there is a problem. We have flown in the last couple of years with Ryanair, Aer Lingus, Aer Arran, BA, Air Canada and Easyjet, and have never had an issue.