Period trackers: How apps exploit your menstrual cycle

As a late adopter of smartphones, Marie Kochsiek couldn’t help but feel excited the first time she encountered the millions of apps available on the market.
Period tracking apps, especially, caught her attention. Finally, she thought, she wouldn’t need to manually fill in the papers her gynecolog handed her after every visit, but instead she could digitally monitor her menstrual cycle.
“I was so excited back then that I told a friend about it. She asked me if I was sure it was a safe option. She was involved in internet politics,” Kochsiek recalls.
Behind the pink interfaces and mascots, some apps track more than a user’s period. They often have access to a user’s name, location, email address, browsing hory and more — all to provide targeted advertising.
Protect your data: Alternative period trackers
When reports started to emerge on how these apps monetize and sell user information to third parties, Kochsiek was concerned but refused to go back to the old analog way.
Instead, Kochsiek felt motivated to develop an alternative app called .drip — a cycle tracker that only stores data on your device.
As with other cycle apps, .drip allows users to monitor their menstrual health and keep track of their flow and fertile days.

The difference is that users don’t have to agree to invasive practices, such as permitting an app to access their microphone or having intimate data, like sexual encounters or a week of heavy menstrual flow, stored on a company’s servers many miles away from them.
But the popularity of non-commercial trackers lags far behind bigger players like Mi Calendario Menstrual, Flo and Clue, which add up to 160 million downloads across mainstream app stores.
Period trackers since Roe vs. Wade was overturned
The US Supreme Court’s decision to reverse Roe vs. Wade, a 1973 decision establishing a federal — and constitutional — right to terminate a pregnancy, has sparked new fears about how companies use menstrual data.
“It seems as if these [popular] companies have more to gain from me tracking my menstrual cycle than what I get as an individual. The gain for their commercial business is larger,” says Julia Kloiber, co-founder of SUPERRR Lab, a femin organization advocating for equal digital futures.
For Kloiber, non-commercial trackers pose a safer option to track periods. “It’s important that these alternatives are being developed so people have the option to switch,” Kloiber says.
Open source: More privacy and inclusion
More free and non-commercial alternatives have entered the market in the past few years. They are steering the conversation toward data protection, but also shifting it away from the mass-market approach for these apps.
And that is allowing for space for people with varied identities and needs.
Take for example Periodical, a gender-neutral tracker that works offline and only stores data on your phone or memory card. Like .drip, Periodical is open source, which means that the code behind the app is free to share and check for data security issues, for instance.

Open source technology stays in conversation with the community, says Kochsiek.
“It’s not a blackhole code. When we talk about periods, we talk about women’s health, about our bodies, so the conversation should be transparent and people should be able to join the discussion,” says Kochsiek, the co-founder developer of .drip.
Meanwhile, Hamdam is the first period tracker in Farsi and the only one equipped with the Persian Jalali Calendar. The app provides Iranian users with information on women’s rights, domestic violence and sexual health.
On June 13, a Spanish tech non-profit called Eticas released a report analyzing the privacy practices of 12 popular fertility apps. The report concluded that only one of them, WomanLog, didn’t sell or share user data under any circumstance.
Other apps like Euki, Stardust and Clover also featured among the top-ranked apps. Euki lets users create a personal PIN to access their data on the app.
Tracking more than periods
Research into period trackers and their use of personal data goes back a few years.
In 2019, a UK-based charity, Privacy International, warned how five period trackers shared user data with Facebook and other third parties for commercial purposes.
A year later, the charity filed data requests to another handful of apps and concluded that the data the apps collected was accessible via company servers, making them vulnerable to leaks.
While collecting menstrual data may promote research in a field as understudied as women’s reproductive health, Kloiber says the lack of transparency and compliance with data protection frameworks in tech could also pose a risk.
“At a first glance, it’s just some data points that don’t say a lot about a person. But this [situation in the US] shows that data that seems banal at first needs to be protected because if the political climate shifts, it can turn sensitive,” Kloiber says.
Digital rights activs warn that data from period trackers could be used prosecutors not only in the US, where some federal states were quick to introduce abortion bans after the Supreme Court ruling, but also in Europe, in countries such as in Poland, where terminating a pregnancy is illegal.
“If a woman in the US gets an abortion, authorities could ask [the company behind] the app to provide data that can be used against her,” researcher and founder of the Eticas Foundation, Gemma Galdon, says.
And that data could be something as simple as googling for an abortion clinic.
“That information could also be used their family or their partner,” Galdon says. “There are a lot of risks concerning the use of this data and [some people] are not aware of it.”