Portable & Travel Red Light Therapy

In cabin baggage, generally yes. Lithium battery devices are normally required to travel in the cabin rather than the hold, and each airline sets its own capacity limits, so check yours before you fly. Keep it in your carry on regardless, because these are not items you want to lose to baggage handling. Nothing here is restricted in a way that would stop you travelling with it.

For one area at a time, yes. Output is lower than a full sized panel, but you use a mini panel close to the skin, and proximity recovers much of the difference because light weakens sharply with distance. It will not treat your whole back. It will handle a face, a shoulder or a knee properly, which is what most travel sessions are.

The battery powered ones sidestep the question entirely, which is the main argument for buying portable. You charge over USB and the device itself does not care what country you are in. If a device needs mains power, check whether the supply is rated for 100 to 240 volts, and note that a plug shape adapter is not a voltage converter.

Usually two to four sessions, varying with intensity setting and device size. Pens and small torches often go further because they draw less power. Charge before you leave rather than assuming you will find a moment on the trip, since that is when routines break. If a listing does not state capacity, plan for the lower end.

Technically possible with a small device, though we would not recommend it. Cabin lighting is dim, a bright red device is conspicuous, and you have no control over who is looking at it or from what angle. Run the session in your room instead. A missed session on travel days costs you very little over the length of time these devices work across.