I've been flying with an epipen or two for the past 2 years. Pre liquids hassling, I kept it in my purse and it was never questioned. Post liquids hassling: Domestically (USA), I've just put them in the baggie, no declaration, and no hassles. Internationally: CDG took them out of the baggie, opened the case, questioned me. I had to take the flattened box out of my carry-on to show the prescription label, that it matched my passport and explained it was medication I couldn't travel without. I haven't had trouble in any other European airport (Rome, MUC, FRA, LHR, TLS). Since the CDG incident, I've traveled with a note on hospital stationary signed by my doctor that says I'm supposed to travel with them. Haven't been asked for it yet.