Well, this is concerning.

If you've been converted to menstrual cups, there are two things that are very likely to be true - one, you'll have waved your pads and tampons goodbye and two, you're trying to convince every woman in your life to do the same. They offer a cheap and eco-friendly alternative to traditional menstrual products, but new research reveals that they could be worse for causing toxic shock syndrome (TSS) than tampons. TSS, for anyone who's never read the back of a box of tampons, is a rare but life-threatening condition that's caused by certain bacteria getting into your bloodstream and is usually linked with highly absorbent tampons being left in the vagina.

A post shared by Amber Dudley (@amberd4296) on Jul 2, 2017 at 1:46am PDT

A study in Lyon, France, last year compared hundreds of used tampons and menstrual cups and found that the cups are more likely to cause you to produce Staphylococcus aureus – the bacteria that causes TSS, reports Metro. This may be because they can allow for air to get into the vagina, creating a more bacteria-friendly environment. The researchers, however, did not go as far as to recommend that women stop using menstrual cups but rather that they use them hygienically. They should be emptied every four to six hours and should not be used overnight. Anyone using one should also make sure it fits their vagina correctly.