The menstrual cup is a big one. Reusable sanitary pads are a thing. Absorbent period pants are also gaining popularity.

But recently, an older technique is resurfacing as a new way to deal with periods. Presenting the sea sponge.

Menstrual sponges are, as the name suggests, sponges that you insert inside yourself in place of a tampon.

They come from the sea and are all-natural, so have won major points in the anti-chemical, all-organic community, they’re better for the environment than tampons, and one sponge can be rinsed and reused for between six and twelve months.

Which sounds pretty snazzy, right?

Except sea sponges aren’t the super-healthy, super-safe alternative to tampons their fans – and the companies selling them – would have you believe. Dr. Jen Gunter wrote a brilliant post about the hidden risks of the product in response to Glamour, who recently included sponges in an article titled: ‘4 Genius Alternatives to Traditional Pads and Tampons.’

Dr. Jen notes that the sponges are ‘untested and potentially very unsafe’. Plus, the sponges can be filled with dirt, grit, and all kinds of other stuff you reeeeally don’t want to be putting inside your vagina.

‘According to the Food and Drug Administration, twelve “menstrual sponges” were tested at the University of Iowa in the 1980s and they contained sand, grit, bacteria, and “various other materials,”‘ notes Dr. Gunter.

‘Another batch was tested by the Baltimore district laboratory and in addition to the sand, grit and bacteria they also found yeast and mould.

‘One sample contained Staphylococcus aureus (the bacteria that causes toxic shock syndrome). As the FDA notes there is least one case of toxic shock syndrome associated with the sea sponge and another possible one.’

So, yeah, not quite as risk-free as their all-natural reputation suggests.

There are also major safety concerns when it comes to the sponge itself, not just all the stuff it could be hiding inside. Dr. Gunter notes that pieces could break off inside the vagina, collecting bacteria and damaging the body’s delicate pH balance.

Oh, and the sponge can also be extremely hard to clean (think of how gross your kitchen sponge is right now), and may cause abrasions when you’re inserting it, thanks to its naturally rough texture. Ouch.

We spoke to experts from the Royal College of Royal College of Obstetricians and Gynaecologists (RCOG) to double check these risks, and, well, Dr. Jen is entirely correct.

Dr Pallavi Latthe told metro.co.uk: ‘Menstrual or sea sponges are branded as a re-usable and natural alternative to tampons and other sanitary products.

‘They are aquatic animals taken directly from the sea which feed on bacteria and other food particles in the water.

Because of their natural environment, the sponges often contain sand, seaweed, shells and bacteria.’

‘As little scientific research has been conducted into the safety of these unregulated products, we would advise women not to use them as they may cause infection or toxic shock syndrome.’

So, just to recap, DO NOT PUT SPONGES INSIDE YOUR VAGINA. It’s quite clearly not a good idea.