Light to medium period: Yes. When you are in water, blood cannot leave your body because of the water pressure. When you get out of the water, the blood will naturally come out and flow into your swimsuit (replacing the water in the absorbent part). Blood contains iron and is therefore heavier than water, which is why it settles at the bottom of period beachwear.
If you have medium to heavy menstruation , period beachwear is better suited to use as extra protection for a tampon or menstrual cup. In this case, we advise against wearing period beachwear alone while swimming.