Are Period Tracker Apps Safe? Cambridge Warns of “Frightening” Data Risks

It’s the question few users stop to ask while dutifully logging cramps, moods, or PMS cravings: who exactly is watching? 

According to a new report from Cambridge University’s Minderoo Centre for Technology and Democracy, your menstrual app might be tracking far more than your cycle – and turning it into profit.

Researchers at Cambridge are calling for the NHS to create its own government-backed menstrual tracking app, warning that current options, which dominate the $60 billion femtech market, are built on business models that commercialise intimate health data.

 

 

“Menstrual cycle tracking apps are presented as empowering women and addressing the gender health gap,” said Dr. Stefanie Felsberger, lead author of the report. “Yet the business model behind their services rests on commercial use, selling user data and insights to third parties for profit.”

“There are real and frightening privacy and safety risks to women as a result of the commodification of the data collected by cycle tracking app companies.”

 

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From Empowerment to Exploitation?

The numbers are staggering. The three most popular period apps have been downloaded over 250 million times, often promoted as tools of empowerment for women wanting to “own their data.” But in reality, that data is worth more to advertisers than users realise – pregnancy-related data can be 200 times more valuable than basic demographic information like age or gender.

The report highlights how tracking data – from hormone levels and sexual activity to contraception and emotions – can paint a vivid picture of users’ habits, vulnerabilities, and life stages. “This data in the wrong hands could enable harms that go beyond reproductive health,” Felsberger warns. “It could impact job prospects, insurance access, or even intimate partner safety.”

 

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The Cambridge Report: A Wake-Up Call

The Cambridge Minderoo Centre, led by Professor Gina Neff, is urging regulators to treat menstrual data as “special category” health information, on par with genetic or biometric data. “Women deserve better than to have their menstrual tracking data treated as consumer data,” says Neff. “Researchers could use this data to answer questions about women’s health, while care providers could use it to improve treatment. But only if the systems are built with privacy in mind.”

The call for reform follows a string of investigations showing that major period tracking apps share user data with advertisers, data brokers, and even social media giants like Facebook and Google – sometimes without meaningful consent.

 

Related: Inside the Tech That’s Quietly Rewiring Your Hormones

Related: The Rise of Femtech: Where Wellness Meets Big Data

Why It Matters Now

In the US, where abortion rights remain politically volatile, menstrual tracking data has already been weaponised. Following the reversal of Roe v. Wade, some states attempted to use app data to identify individuals seeking abortions. In the UK, where reproductive data is technically protected, researchers say enforcement remains weak – and commercial apps still collect data that could be repurposed or sold.

The irony? These apps are marketed as feminist tech, designed to close the gender health gap. Yet the very data that’s supposed to empower women could also expose them to surveillance and discrimination.

“Menstrual tracking data is being used to control people’s reproductive lives,” said Dr. Felsberger. “It should not be left in the hands of private companies.”

 

Related: How Period Tech Became a $60 Billion Industry
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So What Can Be Done?

The Cambridge team proposes several reforms:

• Create NHS-led menstrual tracking apps that store data securely within the healthcare system.
• Enforce stronger regulations on how companies store and share sensitive data.
• Add “delete data” buttons so users can permanently erase their information.
• Educate schools and young women on digital literacy and health data privacy.

They also call on tech companies to stop offering “all-or-nothing” consent and instead give users meaningful choices about what data to share.

 

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The Future of Femtech

The report, titled “The High Stakes of Tracking Menstruation”, is as much a warning as it is a roadmap for ethical innovation. With femtech expected to reach $60 billion by 2027, the need for trustworthy, transparent alternatives is urgent.

“Apps that are situated within public healthcare systems – and not driven primarily by profit – will mitigate privacy violations, provide much-needed data on reproductive health, and give people more agency over how their menstrual data is used,” Felsberger concludes.

It’s a reminder that while technology can close health gaps, it can just as easily widen them. Empowerment without protection isn’t progress – it’s just data with a price tag.