Despite being touted as a safe, eco-friendly alternative to traditional period products, new research has found that menstrual cups are more likely than tampons to cause potentially fatal toxic shock syndrome.
Menstrual cups have risen in popularity of the last few years as a cheaper and more hygienic alternative to tampons and pads.
Brands like Mooncup, Juju, Lunette and DivaCup offer cups made from silicone, rubber or latex which are inserted into the vagina using fingers and a folding technique. Once inside, they unfurl to collect blood and are later removed and emptied, then washed and reinserted.
A study published in the journal of Applied and Environmental Microbiology claims that a common infectious bacteria linked to TSS can remain on the cup, regardless of model or composition, even after being washed as advised.
Researchers tested 15 tampons and menstrual cups made of different materials. They concluded that menstrual cup users were more susceptible to TSS because of the air that enters the vagina when the device is inserted, which might promote the growth of staphylococcus aureus, a common bacteria.
Researchers recommended that women use small rather than large cups, where possible, to minimise the volume of air trapped during insertion.
The study also revealed that even after the menstrual cup was washed three times, a substantial amount of staphylococcus aureus remained on it eight hours later.
"Manual instructions of menstrual cup indicate that the cup could be removed, emptied, and rinsed with tap water before being re-inserted, but our results suggest that women may reinsert a contaminated cup when following this advice," the study reads.
The authors advise that menstrual cup users should invest in a second cup to allow for sterilisation in between uses by placing the used cup in boiling water.
The study also found that tampons composed purely of cotton are not necessarily safer than those made from mixed materials.
"Our results did not support the hypothesis suggesting that tampons composed exclusively of organic cotton could be intrinsically safer than those made of mixed cotton and rayon, or viscose or tampons composed entirely of viscose."