Never cruised with it, and it has been FDA approved for less than a year, so there probably aren't too many people who could answer that question for you. However, I am a licensed pharmacist, and my recommendation to you would be to make sure it has the most current prescription label on it.(ie, not a bottle from several months ago),-- definitely do not bring it unlabeled or transferred into another container, and, if you want to be paranoid about it, a letter from your physician stating that your child uses it for the treatment of epilepsy, but that's only if you really want to cover all your bases. When we were on a 12 night, I brought a 2 week supply of my meds in medication holders, but my daughters meds (she has epilepsy) -- 1 week in a medication holder, & 2 weeks supply (extra 1 week just in case!) in their original bottles, especially because 3 of the meds we were bringing (1 for every day & 2 for "as needed" use) were controlled substances. Epidiolex is a schedule 5, which is the "lowest" schedule (illegal drugs such as heroin AND marijuana are schedule 1), so I would definitely make sure it is labeled properly.
To piggyback off this, I would definitely NOT take it off the ship. While it is legal in the US, it may not be legal in the ports where you are visiting.
