Great question — and totally valid to ask.
UnderSwim is designed with a sealed, waterproof lining that locks flow in and doesn’t let it leak into the pool. The absorbent layers hold up to 3 tampons or 4 regular pads’ worth, and the whole design sits snugly under regular swimmers, so it stays in place and stays sealed.
It’s not magic, just really clever tech — developed specifically for girls who swim during their period and want to do it without tampons or pads.
We’re backed by Swimming Australia for good reason. These undies are built to hold it in, not let it out. 😊
Aug 20, 2025