Can period underwear leak?

Period underwear is designed to be leak-proof, and it works very well when you choose the right absorbency for your flow and the right size. The leak-proof barrier stops flow reaching your clothes, and the absorbent core holds it securely.

Leaks usually only happen if the absorbency is too low for a heavy day, the underwear is full and needs changing, or the fit is too loose. Match the level to your flow, change on heavy days, and pick the correct size to stay protected.