Theia Mania

It’s uncertain whether ancient Greek women wore any undergarments, but at least Persephone occasionally does in this comic.

Though I'm too lazy to go retrieve any sources right now, I'm pretty sure there are accounts that they did wear a sort of garter belt style contraption while they had their periods. Beyond that, they also had loincloths (men and women) called "perizoma". Not sure which era though.