Does Your Period Tracker Sell Your Data? What to Check Before You Download One
A period tracker sees things most other apps never do: when you bleed, how heavy, what symptoms you have, whether you’re trying to get pregnant, and your mood on any given day. That’s sensitive health data, and it’s worth knowing how the app you choose actually handles it before you hand it over.
What US regulators found
In June 2021, the US Federal Trade Commission announced a settlement with the developer of Flo, one of the most downloaded period and fertility tracking apps in the world. The FTC’s finding: Flo had told users its health data would stay private, but shared sensitive information — including whether a user was pregnant — with outside analytics and marketing companies, among them Facebook and Google, without users’ knowledge or proper consent.
As part of the settlement, Flo was required to get users’ clear permission before sharing health data going forward, notify affected users of the disclosure, ask the third parties involved to destroy the data they’d received, and undergo an independent privacy review. The full FTC press release and order are public, and worth reading if you want the details straight from the regulator rather than a summary.
What independent researchers found
Separately, the Mozilla Foundation’s *Privacy Not Included project — a team that manually tests the privacy and security practices of consumer apps and devices — has reviewed a wide range of period and pregnancy trackers over the years. Their published findings describe a recurring pattern across the category: broad data collection paired with vague or permissive privacy policies, and in several cases weak security practices that fell short of Mozilla’s own minimum standards. Most of the period and pregnancy apps they’ve tested carry some kind of privacy warning in their reviews; only a small number have been rated free of significant concerns.
None of this means every period app is unsafe, or that the two examples above are still accurate descriptions of any given app today — companies change their practices, sometimes because of exactly this kind of scrutiny. But it’s a useful reminder that “period tracker” and “handles your health data responsibly” are not the same claim, and the second one is worth checking rather than assuming.
What to actually check before you download one
- Does it require an account at all? An app that can function without your name, email or phone number simply has less of your identity to link your health data to in the first place.
- Where does your data live? On your device by default, or on a company’s server by default? Those are very different defaults.
- Is anything encrypted end-to-end? If the app offers backup or sharing features, check whether that data is encrypted before it leaves your phone, in a way the company itself can’t read — or only “encrypted in transit,” which just means it’s protected while traveling to a server the company can still access.
- Read the actual privacy policy’s data-sharing section, not just the marketing page. Look specifically for whether it shares data with advertisers, analytics companies, or “third-party partners,” and whether that sharing requires your separate, explicit consent.
- Check if there are ads. An ad-supported health app usually means your usage data is part of what pays for it.
Where Cycella stands
Cycella doesn’t ask for an account, an email, or a phone number to work. Your cycle data lives on your phone by default. If you turn on backup or partner sharing, that data is end-to-end encrypted first, on your device, before anything leaves it — we built it so we can’t read it even if we wanted to. There are no ads and no analytics trackers in the app, and we don’t sell or share your data with anyone, because there’s no business model here that depends on it.
We’re a small team still in testing ahead of a December 2026 launch, so we don’t have years of an independent audit trail the way a large company might. What we can tell you is exactly how the app is built and invite you to hold us to it. If anything above ever stops being true, we’ll say so.