Flo

Is Flo safe?

Flo is reasonably safe today, with one big condition: turn on Anonymous Mode if your cycle data could ever be used against you. The app's past is the reason to be careful. Between 2016 and 2019 Flo sent records of users' periods and pregnancies to Facebook, Google and other analytics firms while promising not to, the US Federal Trade Commission said. That led to a 2021 FTC order and $59.5 million in US class action settlements, and in August 2025 a jury found Meta liable for collecting the data. We score Flo 66/100, ahead of Strava at 59 and far ahead of Grindr at 41, which also shared sensitive health data with third parties.

What did Flo share with Facebook and Google?

The FTC's complaint, settled in January 2021 and made final that June, said Flo passed "custom app events" to marketing and analytics firms. These were records of what a user did in the app, and they showed when someone logged a period or said they wanted to get pregnant. The firms named include Facebook, Google, Flurry and Fabric. According to the FTC, Flo built these firms' software kits into the app from as early as June 2016, and Facebook used the event data for its own purposes, including research and development, even though Flo's privacy policy said it would not share "information regarding... marked cycles, pregnancy, symptoms" with third parties.

The order carried no fine. It bars Flo from misrepresenting how it uses data, makes it get express consent before sharing health information, and required it to tell users about the past sharing and to ask the companies to destroy the data. It lasts 20 years. FTC orders like this one describe the agency's allegations, and Flo agreed to the order to settle them.

The Frasco v. Flo class action and the Meta verdict

The same facts led to a class action in federal court in San Francisco, Frasco v. Flo Health. Users argued that software kits from Meta, Google and Flurry inside the app let those firms record private health information without consent. Google ($48 million) and Flurry ($3.5 million) settled before trial. Flo settled for $8 million on 31 July 2025, during the trial. All three deny wrongdoing.

Meta did not settle. On 1 August 2025 the jury found Meta liable for its role in the unauthorised collection and commercial use of health data entered into Flo, according to class counsel. We could not confirm a damages figure. The claim deadline for the $59.5 million settlements was 15 October 2026, and the final approval hearing is set for 29 October 2026.

What Flo collects and shares now

Flo's current privacy policy, effective 31 August 2026, says it does not sell personal data and does not share health data with third parties for marketing. With your consent it does share advertising identifiers, your IP address and details such as your age group and subscription status with AppsFlyer, Firebase and TikTok Ad Manager to measure its ads. AppsFlyer can pass these to partners including Meta, Google Ads and Pinterest. Apple's label matches this: purchases, coarse location, identifiers and usage data may be used to track you across other companies' apps, while health data is linked to you for analytics and personalisation but not for tracking.

Accounts that go unused are kept for three years before deletion, unless you ask for earlier deletion.

Does Anonymous Mode protect you after Roe v. Wade?

After the US Supreme Court overturned Roe v. Wade in June 2022, people worried that period-tracking data could be used as evidence in states that ban abortion. Flo brought forward the launch of Anonymous Mode in response. It is free for every user. Your health data travels through a Cloudflare relay using Oblivious HTTP, so Cloudflare sees your IP address but not your data, and Flo sees your data but not who you are. Flo says this means it cannot answer a legal demand for an Anonymous Mode user's data.

There are trade-offs. The switch is permanent and Flo cannot recover your old account, and you lose any features that need your identity.

For everyone else, Flo says it needs a legally valid subpoena or court order, reviews and challenges demands, and emails you where the law allows. That is a promise, not a guarantee: a valid court order can still reach data that is linked to you.

How to use Flo more safely

1. If an abortion ban or a custody dispute could ever make your cycle data sensitive, switch to Anonymous Mode before you log more.
2. Say no to the tracking prompt on iPhone and to marketing consent in the app, which stops ad identifiers going to AppsFlyer, Firebase and TikTok.
3. Log only what you need. Notes about sex, symptoms or pregnancy tests are the most sensitive entries.
4. Do not connect Apple Health or Google Health Connect unless you want that data in Flo too.
5. If you stop using Flo, delete your account rather than the app, or your data stays for three years.

How we scored it

Scams and harmful content (78) is Flo's strongest factor, because it has little contact with strangers. Privacy (55) and the regulatory record (55) are its weakest, held down by years of undisclosed sharing of health data, the FTC order and the class settlements. Security (70) reflects strong encryption and certificates with no breach found, but no end-to-end encryptionEnd-to-end encryptionEncryption in which only the sender and the recipient can read a message. The company running the service cannot see its content.More in the glossary of health data.