Flo Health denies claims it unlawfully shared app users’ data with Meta

Europe’s first femtech ‘unicorn’ has denied claims that it unlawfully shared users’ personal data with the social media platform Meta.

The period-tracking app Flo Health is facing a possible multi-million dollar data privacy lawsuit in the US, accused of unlawfully sharing app users’ personal data with Meta for targeted advertising.

The case, which is taking place in San Francisco, began on Monday, 21 July and involves five named claimants who say they did not permit personal data, including the dates and lengths of the periods, to be shared with the social media platform, Sifted reports.

Flo Health denies all of the claims made against it, and Meta, which is also on trial, denies receiving any sensitive data from the company. 

Flo Health is considered to be Europe’s first FemTech unicorn after raising $230 million (£155.7m) in Series C investment in July 2024. 

Founded in 2015, the app now has over 75 million active users, according to the company’s LinkedIn page, allowing people to track period and ovulation cycles, monitor symptoms and access personalised health insights and educational content on topics such as pregnancy and perimenopause. 

Claimants say that Flo integrated tracking tools, including Meta’s software development kits, which automatically transmitted sensitive personal data as users engaged with the app, according to reports from Law360.

They are seeking $1,000 in statutory damages under California’s medical privacy law for 13 million Flo users who downloaded and registered on the app between late 2016 and early 2019, meaning the company could face up to $13bn in potential damages.

Claims brought against Google for the same as part of the same case were settled earlier in July 2025 for an undisclosed sum.

In a statement to Femtech World, a spokesperson for Flo said: “Flo is committed to protecting the privacy of its users, and any allegation otherwise has no merit. We are building a better future for women, and are steadfast in our commitment to protecting your privacy and data.”

Calls for stricter regulation in femtech 

In 2021, users of the app filed a lawsuit against Flo, Google and Meta following a settlement between Flo and the Federal Trade Commission after allegations that the company shared health information with third-party advertising companies without permission.

Flo denies these claims and says it agreed to settle the matter to “avoid the time and cost associated with litigation”.

A report from Cambridge’s Minderoo Centre for Technology and Democracy, published last month, called for stricter regulation and governance of femtech apps, highlighting how menstrual cycle tracking tools are a “gold mine” for consumer profiling.

In the report, lead author Dr Stefanie Felsberger argues that the financial worth of this data is “vastly underestimated” by users who supply profit-driven companies with highly intimate details in a market lacking in regulation, leaving them at risk of data and privacy breaches. 

However, in a LinkedIn post from 12 June, Sue Khan, vice president of privacy and data protection officer at Flo, responded to the report stating: “We have never – and will never – monetise or sell user data. We do not see personal data as a commodity, and categorically reject the notion that women’s health data should be treated as a goldmine for advertising.”

Potential impacts for the wider sector 

Stephanie Caird, life sciences partner at UK law firm Mills & Reeve, told Femtech World that while data and privacy laws differ significantly between jurisdictions, the case against Flo may well lead to calls for stricter regulation of femtech apps, with potentially wide-reaching implications for the whole sector. 

“We suspect that the case might fuel calls for stronger regulation of cycle tracking and other femtech apps,” Caird says.

“We would note that the data privacy regime in the US differs from the UK and Europe, particularly as different states have slightly different rules on personal data, and there is an overarching federal law relating to protected health information [Health Insurance Portability and Accountability Act].

“Even so, if there is a decision that the sharing of data by Flo was improper, the effects could be felt here in the UK, as user trust and confidence in the security of their personal data and how this is being used may be undermined. This could lead to nervousness from users impacting the wider femtech sector, which could further reduce engagement with and investment in an already underfunded eco-system.”

Caird adds: “It is worth noting that there are already a variety of frameworks in place in the UK which, when taken together, should be providing a sufficiently robust framework to protect users’ data.”