I have over a dozen meds I have to bring with me -- Rx, OTC and prescribed vitamins. I also have additional medical items that I travel with. And I live in Canada and most of my plane travel is to the USA, so there are borders involved.
I travel with Rx and OTC meds in their original bottles: for each Rx med I have had the pharmacy give me an empty labeled bottle of the smallest size (8 dram); I refill each from my larger normal bottles before each trip. For OTC meds, I have bought one bottle of the smallest size and then just refill it from the larger normal bottles. I bring trip length + 1 week worth.
For the vitamins, their original bottles are HUGE and some of them are glass, so bringing those is not an option. Instead, I created 4x6 "cards" printedd on photo paper for each vitamin: a picture of the bottle and a table of ingredient info from the manufacturer's website, plus name and dose info. Those cards travel in the container I carry the vitamins in. The vitamins themselves, each one gets it own ziploc snack-size baggie which is in turn put into a quart baggie. Both are labeled with what it is (I used address labels and printed them myself). they are all run of the mill vitamins, so no issues there.
The Rx pre-filled syringes stay in their original boxes (one per).
When I arrive at my destination, I fill a one week Dosett-Maxi with my meds (they just fit :-( ). If I don't do this I invariably end up accidentally missing a med at a some point. At home I use the same Dosett-Maxi. Yes, it takes some time at destination to do this (and refill it if the trip is longer than a week), but I just consider it some good down time and factor it in to our plans.
All of this plus some additional medical items takes up a small rolling carry-on bag (fits under the seat size). I have a luggage tag I got online that says "MEDICAL" that I attach to the outside of the bag. It travels free and is not counted towards my carry-on allowance. As others have noted, a medical bag is ONLY allowed to contain medical items, NOTHING ELSE. And airlines are allowed to check the contents to confirm that. I have only run into issues three times when an airline employee did not know the law and their own policy, but one of their co-workers quickly educated them and I was able to board; have never had the airline actually inspect the contents, but I know they can.
I do not check any medical items -- things sometimes happen to checked bags (delays, theft, lost, dropped, smushed), and they undergo extremes of temperature and pressure which can have a negative impact on many medications or medical equipment. So carry-on it is.
SW