VICIOUS CYCLE

Millions of women are using digital platforms to track their periods, without necessarily thinking about the implications for their personal data. Katie Rosseinsky talks to the experts about the risks, and hears from women who've quit the apps

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You're lethargic. Overcome with ravenous hunger. And if anyone in your path does something even remotely irritating? Let's just say that you might not react with your usual patience.

You glance at your phone and a notification glows on the screen: your period tracking app is reminding you that, yes, you're in the luteal phase. Suddenly it all makes sense.

Millions of women around the world are using apps to track and make sense of their menstrual cycle; some of them will turn to these platforms to discover when they are most fertile, to try to conceive. One 2024 study estimated that downloads for three popular apps - Clue, Flo and Period Tracker - have surpassed 250 million. They've become a handy way for users to record and keep tabs on changes to their mood or any physical symptoms throughout the month.

It is hardly surprising that women are keen to find ways to arm themselves with as much information about their cycle as possible. Menstrual health, and women's health overall, remain under-researched and underfunded. It tends to take two years to be diagnosed with polycystic ovary syndrome (PCOS) and between seven and nine years to get diagnosed with endometriosis; both conditions significantly impact the menstrual cycle. Anecdotally, at least, phrases like "it's just your hormones" can still be all too common refrains when you raise issues with a doctor.