Yes, you can. If you're already on your period or there is even a slim chance that your period might start during your journey, you should always pack a good supply of pads and/or tampons.

Wearing a tampon on a plane is perfectly safe for most people, but there are logistical and health considerations for long-haul flights. The primary concern is Toxic Shock Syndrome (TSS), a rare but serious condition linked to leaving a tampon in for longer than eight hours. On international flights that exceed 10 or 12 hours, it is easy to lose track of time or fall into a deep sleep, potentially exceeding the safe usage window. Additionally, the low humidity and pressurized cabin air can sometimes lead to increased vaginal dryness or discomfort. Many frequent travelers prefer using a menstrual cup or period underwear for long flights because they can often be worn for up to 12 hours, providing a larger "safety margin" if there are bathroom queues or delays. If you choose to use a tampon, it is best to use the lowest absorbency needed for your flow and to set a "change timer" on your phone or watch to ensure you stay within the 4-to-8-hour window, maintaining your health and comfort while crossing multiple time zones.