Tampons and pads are just sooo last year. Well, not quite, but plenty are predicting they will eventually become a thing of the past.

A number of innovative, female-run companies are campaigning for an end to the two-party system of feminine hygiene and, in the process, disrupting a multi-billion-dollar industry.

Take Flex, for example. The brainchild of Californian marketer Lauren Schulte, it’s a disposable disc-shaped device that you insert in front of you cervix to temporarily halt your flow.

Wear it for up to 12 hours, then toss it.

Sexy time meets time of the month. Image: Flex.

Think of it kind of like a menstrual cup, but with one fabulous bonus: you can wear it during sex.

It's made from flexible, medical-grade polymer that's latex-free, BPA-free and hypo-allergenic, and the company claims your partner will barely be able to feel it.

Unsurprisingly, there's big buzz. The 30-year-old has already raised $4million from investors and over 20,000 samples were shipped across North America last month. (The trial was set to include other countries, including Australia, but had to be scaled back due to overwhelming demand.)

It was the recent slipping of the stigma around periods - note the Chinese Olympic swimmer who told the media her flow was making her tired, and the marathoner who ran with blood-stained leggings - that encouraged her to make it happen.

“The more of us that go out and talk about our own experiences,” she told The Washington Post, “the more mainstream it becomes.”

"How thin is your underwear?" Part 3, featuring some v. serious hand modeling (& @melinadimarco's lovely face!!)

A photo posted by THINX (@shethinx) on Sep 24, 2016 at 4:06pm PDT

Also seizing on the shift is Miki Agrawal with Thinx, reports The Washington Post.

When most of hear the phrase 'period undies' we think about those saggy, granny knickers we sacrifice to stains each month. But the 37-year-old has re-imagined the concept by, well, embracing it.

Thinx are multi-layer, antimicrobial, leak-proof, washable undies that hold up to two tampons-worth of blood.

“It’s liberating,” Agrawal told the paper.

“Once you’re free of the messiness, of the frustrations, of the stains, you’re more likely to talk about it — your period.”

Thinx, via GIPHY

You can buy Thinx online, but there are Aussie companies with similar products - Modibodi, period-proof underwear, for example.

And it's not hard to see why so many brands are getting in on this niche. The benefits are obvious - it's cheaper in the long run, not everyone can use tampons, landfill is reduced and there's no unexpected, late-night bolt to the supermarket.

Of course, it'll be a while before products like these become mainstream, but we'd hardly be surprised if the feminine hygiene aisles of the future end up looking a lot more diverse.