Yes, you can take non-prescription medication on a plane, but it’s best to pack it in your carry-on bag and keep it in its original packaging. Solid pills and tablets are not subject to volume restrictions, and you can transfer them to a pill organizer if you prefer. For liquid medications like cough syrup, follow the “3-1-1 rule” (containers 3.4 ounces or less in a single quart-sized bag) for carry-on, unless they are medically necessary, in which case you can exceed the limit but must declare them at security.