Having spent the previous 45 minutes debunking Ukip, Jeremy Clarkson and Rachel Dolezal, she closes her show with a call to revolution… against the tampon tax. Women pay VAT on sanitary products because they are deemed luxury, non-essential items “unlike, say, herbal tea, houseboat moorings and flapjacks” – the last of which Christie suggests women should start using as an alternative.

If you spend any amount of time at the Edinburgh Fringe you start to notice joke clusters, topics and ideas that a number of comedians have fallen upon and turned inside out for comic effect. It stands to reason – comedians read the same news stories and notice the same trends as the rest of us. This year I’ve noticed clusters around Twitter trolls, Uber, emojis and pugs, for example. Tons of jokes about pugs – no idea why.

It used to be the done thing to deride female comedians for talking only about periods, even though few of them actually did. Before this year, I can’t remember the last time I heard a routine on the topic. Even Jo Brand, often pegged as the period gagsmith par excellence, says that she didn’t talk about them as much as everyone thought she did. “I went back through my material to see exactly how long I’d got on periods. It was actually just one-and-a-half minutes out of my whole comedy career.”

Now a new wave of female comedians is reclaiming the period joke. As the rising Danish stand-up Sofie Hagen put it in a blog last month: “Most female comedians would not dare to talk about it, because most of us are too stubborn – we do not want to become the stereotype people have created about us. Unfunny, period-babbling, ovary-owning, kitchen-abandoning… Anyways. Why can’t I talk about my period?”

Their jokes are part of a zeitgeist that has seen women across the globe gleefully tweet Donald Trump about their menstrual cycles after the would-be President accused Fox News anchor Megyn Kelly of being on her period during the first Republican debate (“She had blood coming out of her eyes, blood coming out of her wherever,” he said). Elsewhere, the drummer Kiran Gandhi has been lauded for her decision to run the London Marathon while “free bleeding” (not wearing a tampon) to remove the stigma around periods. And the artist Rupi Kaur successfully took on Instagram after it censored a self-portrait in which her pyjamas were stained with a spot of menstrual blood.

The main comic inspiration at the Fringe is the risible notion that sanitary products are considered less essential, and therefore more taxable, than a range of daft things like cake decorations and exotic meats. Jenny Bede ends her show with a lush ballad on just this subject. “And it’s largely gone down very well,” she says. “You sometimes get a couple of men saying ‘Urgh’ but I say to them, ‘Don’t worry, you can’t catch periods, it’s fine.’ I quite enjoy it if there’s an uncomfortable reaction. You feel quite empowered.”

Sh!T Theatre, aka Louise Mothersole and Rebecca Biscuit, also tackle the topic in their theatre/cabaret show Women’s Hour. A dynamic take on the Radio 4 institution – “One whole hour out of 24!” – it includes a violent takedown of Kinder Eggs for girls and boys, a sexy RnB routine in which they sweep the floor and songs whose lyrics are harvested from misogynist comments online. Performing in white shirts and shorts, Doc Martens and clownish face paint, the pair also, inevitably, mock the idea of tampons as a luxury. “I can’t wait to get home at the end of a long day and pop one in… Such a treat.”

“The tampon tax is a thing that’s so funny you can’t quite believe it’s true. The whole show is about pointing at things and saying, ‘Come on guys, this isn’t right’,” says Mothersole. “Ironically we have to buy a lot of tampons for the show so our budget is really affected by the tax,” adds Biscuit.

The idea of one hour’s broadcasting a day to cover everything about being a woman struck them as “hilarious, ridiculous, impossible”. Like the radio programme, they jump between topics (“Some have genuinely been spoken about on Woman’s Hour,” points out Mothersole. “Ankle socks, culottes, hypertonic pelvic floor muscles, cooking the perfect buckwheat drop-scone…”) though it’s unlikely that Jenni Murray has ever rapped about her ingrowing hairs. Is it a women-only show? “We get a lot of men coming and they really like it. It’s not just for women, we’re not having a pop at men at all.”

The tampon tax has also inspired an eye-catching spoof of Taylor Swift’s video for “Bad Blood”. Written by Bede and Cariad Lloyd, it assembles a host of female comedians including Gemma Whelan (aka Game of Thrones’ Yara Greyjoy), Alice Lowe, Rachel Parris and Pippa Evans. Instead of the superhero aliases of Swift’s squad, these kickass heroines have names like Madame Ovary, Heavy Flow, Polly Sistic and Toksvig Shock. The lyrics rail against VAT – “Ladies, now we got bad blood. Our Super Pluses are adding up. Why you keep on taxing us?” – and offer up an increasingly bizarre range of alternatives. It has had 160,000 views on YouTube so far.

“When I started looking into the tampon tax, I was really shocked at all the things that were exempt – male razors, crocodile meat and so on,” says Lloyd, who is better known as one of Austentatious, the Jane Austen-themed improv troupe. In her show last year, she had a character called Sanitary Bag Lady, in which she dressed up as the woman on the front of the hygiene bags that are found in toilets. “I wore a massive hat and would scream at any man who looked disgusted by me,” she recalls. “It’s not something to be disgusted by. I’ll talk about what I want, whether it’s my relationship, my children or my period. Is it because men have told us not to talk about periods that we’ve stopped? Not any more.”

Tiff Stevenson’s show is wide-ranging, confident, feminist take-down of everything from Dubai to drinks advertising, female rappers to band T-shirts. She ends with a hymn to the “vagina house” she builds every month in her womb and a heartfelt exhortation to women to celebrate their bodies. She recalls how, growing up, she was shamed by advertising into thinking menstrual blood was blue. As for the tampon tax: “If tampons are luxury where’s my Chanel Tampax, where’s my Dolce & Gabbana with wings?” she asks.

“We constantly get told it’s all we ever talk about but I’ve never seen anyone do any material on it until now. I think it’s a case of various female comics taking back the power,” she says. “For a long time we felt shamed into silence and this is a kickback. We can talk about whatever we want. For a long time to get on in stand-up women felt like that had to become more masculine. I say, the more women talk about it, the merrier. Men are not afraid to talk about their penises.”

Not all female comedians at the Fringe are talking about tampons and cramping, of course. Katherine Ryan has an hour of celebrity-bashing, Aisling Bea’s show ponders the nature of shame, while Jessie Cave talks about how a one-night stand turned into the happiest moment of her life and Scottish newcomer Fern Brady airs her anger management issues. Danish stand-up Sofie Hagen talks about her years as a Westlife fan and psychiatric patient. Just like male comedians, they are talking about what they know for laughs. If that happens to be periods, so be it.

“Lots of male comics have come on board with the idea,” says Stevenson. They say, ‘If I bled once a month for 40 years of my life it would be all I ever talked about’.”