Women around the world are being urged to think twice about the privacy trade-offs that come with using period tracking apps. While these apps promise convenience and empowerment, a new report from researchers at the University of Cambridge warns they might come with "real and frightening" privacy and safety risks.

Let's unpack what the experts found — and what it means for millions of women who rely on these tools every month.

More Than Just Dates and Symptoms: What These Apps Really Know About You

Most period tracker apps ask you to log your cycle dates, but many also collect a surprising amount of additional data:

Taken together, this paints an intimate portrait of a user's body, health, and even family planning intentions. As the researchers point out, this information can reveal whether someone is trying to conceive or might be expecting — data that advertisers consider extremely valuable.

A Gold Mine for Marketers — And a Minefield for Women

The Cambridge team, led by the Minderoo Centre for Technology and Democracy, highlights a disturbing reality: the data you share with your period app may not stay private.

"Cycle tracking apps are a lucrative business because they provide companies with extremely valuable and fine-grained user data," the report states. This data is often packaged and sold to third parties — feeding targeted ads and consumer profiling on an enormous scale.

It's no surprise, then, that global downloads of the three most popular cycle tracking apps have now topped 250 million. Many women start using them when planning a pregnancy, which often leads to big changes in shopping habits — a marketer's dream come true.

More Than Ads: The Hidden Dangers of Data Leakage

Unfortunately, the consequences go beyond seeing more baby product ads on your feed. The researchers warn that if this sensitive information falls into the wrong hands, it could lead to:

These are not just hypothetical scenarios. In an era where data breaches and privacy scandals are all too common, unsecured personal data can pose serious, real-world threats.

So, What's the Solution?

The Cambridge researchers are calling for stronger oversight of the "femtech" industry — a booming market of apps and gadgets designed to help women manage their health.

Dr. Stefanie Felsberger, lead author of the report, argues that while period trackers are marketed as empowering tools to close the gender health gap, the underlying business model relies heavily on monetising user data.

"Women deserve better than to have their menstrual tracking data treated as consumer data," said Professor Gina Neff, executive director of the Minderoo Centre.

The team recommends several practical steps:

Bottom Line: Be Informed, Stay Safe

It's easy to see the appeal of cycle tracking apps — they help women plan pregnancies, monitor their health, and better understand their bodies. But as the Cambridge report highlights, it's crucial to look beyond the convenience and consider who else might be benefiting from your personal information.

For now, if you use a period tracker, take a moment to:

As digital health tools become more advanced, demanding better privacy protection is more important than ever. After all, women's health data should serve women — not advertisers.