The question of how to pack prescription meds (original containers vs. pill packs/daily dispensers) comes up a lot.
We live in Vermont and usually depart from US airports. I have always packed prescription meds in daily dose ziplocs, with all the pills for the day mixed together. I bring along a sheet of paper with the original prescription labels attached for all the medications contained in the baggies as well as a letter from the prescribing physician. Never had any trouble with this when traveling from/to/within the US, and the TSA and US Customs websites confirm that this method is OK:
https://www.tsa.gov/blog/2014/09/05/tsa-travel-tips-traveling-medication
TSA does not require passengers to have medications in prescription bottles, but states have individual laws regarding the labeling of prescription medication with which passengers need to comply.
US Customs website says medications "should" be in original containers, but if they are not, you need doctor documentation:
https://help.cbp.gov/app/answers/detail/a_id/1160/~/traveling-with-medication
Prescription medications should be in their original containers with the doctor's prescription printed on the container. It is advised that you travel with no more than personal use quantities, a rule of thumb is no more than a 90 day supply. If your medications or devices are not in their original containers, you must have a copy of your prescription with you or a letter from your doctor. A valid prescription or doctors note is required on all medication entering the U.S.
We have a trip coming up where we will depart from Montreal. I checked with the CATSA website, and it states the following:
https://www.catsa-acsta.gc.ca/en/medication-and-medical-items
Bringing a day-by-day pill separator is not an issue for security; however, there may be other considerations about travelling with medication, especially when travelling outside of Canada. We recommend finding out more at http://travel.gc.ca/travelling/health-safety/medication.
When I looked at the above-referenced website, the directive is as follows for international travel:
Pack all medications in your carry-on baggage in their original, labelled containers to facilitate airport security and customs screening. Prescription medication is exempted from the liquid restrictions but must be presented to the screening officer separately from your carry-on baggage.
Do not try to save luggage space by combining medications into a single container.
Language further down the page indicates that original packaging/labeling is a requirement to return to Canada.
So, in conclusion, seems as though Canada requires international travelers to package prescription meds in the original containers, no baggies or daily dispensers. The US does not. I will pack accordingly for our upcoming trip.
Hope this helps other travelers.