elizabeth

Certainly, bringing melatonin on a plane is allowed, but it's advisable to verify the airline's and destination country's customs policies before traveling. Generally speaking, melatonin is not considered a banned item, and you should be able to pack it in either your checked or carry-on luggage.
However, it's worth noting that rules regarding medicines and supplements may differ depending on the country, so it's best to review the laws and regulations of your destination before departure.