What Flo Health actually does
Flo Health is a period, ovulation, and cycle-tracking app operated by Flo Health UK Limited, registered in London, and it is one of the most widely used apps in this category. The free tier covers real day-to-day tracking rather than a stripped demo, with Flo Premium layered on top as a paid add-on.
The core product
The free tier lets users log periods and symptoms, see cycle and ovulation predictions built from that logged data, view a shared calendar, and post questions anonymously in the Secret Chats community feature. Everything runs as a mobile-only app on iOS and Android, with no separate web dashboard for day-to-day tracking. Predictions improve as more cycles are logged, so the app becomes more useful with continued use rather than being accurate from day one.
What's new or notable
Flo Premium sits on top of the free base rather than replacing it, adding a symptom checker, daily insight content described as written with input from outside health professionals, a Health Assistant chatbot, a "Flo for Partners" feature, cycle-trend analysis over time, detailed pregnancy tracking, and a downloadable report designed to be shared with a doctor. Flo also markets itself as FSA/HSA-eligible in the US, letting some users pay for Premium with those health-spending accounts — a detail worth checking against your own plan's rules rather than assuming eligibility. On the privacy side, Flo's Anonymous Mode has been expanded with what the company describes as Oblivious HTTP technology and post-quantum cryptography, intended to stop Flo itself from being able to link logged health data back to a specific person.
Who should use Flo Health
Great fit if…
- You want real free tracking, not a trial — period and ovulation logging, symptom tracking, the calendar, and Secret Chats are all free permanently, not a time-limited teaser for Premium.
- You're comfortable letting predictions improve over a few cycles — the app is built to get more accurate the longer you log, so it suits people willing to track consistently rather than expecting day-one precision.
- You want to bring a structured report to a doctor — Premium's exportable report is built specifically to hand to a clinician, which suits anyone already planning that conversation.
Skip it if…
- You need medical evaluation, not predictions — everything Flo produces, on either tier, is a statistical estimate from self-reported data, not a clinical assessment.
- You want one clear published price before committing — Flo Premium's cost is not listed as a flat figure on the pricing page; it varies by region, platform, and ongoing promotions, so you won't know the exact number until you're in the app.
- You're uncomfortable with any default data-sharing settings — cycle and fertility data is unusually sensitive, so anyone with strong preferences should actively review Anonymous Mode and the privacy portal rather than trust the defaults out of the box.
Pricing in detail
Flo's own pricing page does not publish a flat monthly or yearly figure; it confirms only that monthly and yearly Flo Premium subscriptions exist and points users to an in-app or help-centre price, which varies by region and platform.
| Plan | Price | What's included |
|---|---|---|
| Free | €0 | Period and ovulation predictions, symptom tracking, calendar, cycle history, Secret Chats, Anonymous Mode |
| Flo Premium (monthly or yearly) | Not published as a fixed figure — varies by region, app store, and promotions; check in-app pricing | Everything in Free, plus daily insight content from outside health experts, symptom patterns and predictions, Symptom Checker, cycle-trend analysis, Health Assistant chatbot, Flo for Partners, detailed pregnancy tracking, and a downloadable doctor's report |
Where it falls short
- Predictions, not diagnosis — both tiers work from self-reported data and pattern recognition; Flo frames its output as insight to bring to a clinician, not a substitute for one.
- No single published Premium price — anyone comparing costs across apps has to actually open Flo and check the current regional price rather than relying on one number.
- Only worth using if you actually log consistently — the accuracy of predictions depends heavily on regular logging, so sporadic use produces weaker results on either tier.
Privacy & data
Flo states it encrypts data with AES-256 at rest and TLS 1.3 in transit, and says access to user data is restricted to authorized staff only when necessary to provide the service or meet a legal obligation. The company says it applies GDPR-style rights — access, deletion, and export — to every user regardless of where they live, and that deleting an account removes all associated data. Its Anonymous Mode goes further: it is designed to strip identifiers such as name, email, and IP address from health data using what Flo describes as Oblivious HTTP technology plus post-quantum cryptography, so that, per the company's own description, "Flo can view your health data, but does not know who it belongs to." Flo's privacy materials do not spell out fixed data-retention periods beyond "for as long as you have an account," and they do not explicitly address whether any data is shared with advertising partners — anyone with strong feelings about that should read Flo's full privacy policy and FAQ directly rather than assume either way.
How we checked this
This review draws on Flo's published pricing page, the Flo Premium feature page, and its privacy portal (flo.health/pricing, flo.health/flo-premium, flo.health/privacy-portal), all reviewed on 4 September 2026, plus the company's own descriptions of Anonymous Mode and its encryption standards. We did not log a cycle in the app ourselves to test prediction accuracy; the description of features and how tracking works is drawn from Flo's own product documentation, not hands-on use. Prices and features can change, so anyone deciding today should verify current terms directly in the app or on Flo's site.
What you get, what you give up
What you get
- Free period, ovulation and symptom logging plus Secret Chats, not a stripped trial
- Anonymous Mode strips the account from directly identifiable personal data
What you give up
- Cycle and symptom predictions are statistical estimates built from the data a user logs, not a medical assessment — accuracy depends on how consistently someone tracks, and it takes a cycle or two of logging before predictions settle in.
- The free tier covers logging and basic predictions, but the symptom checker, most expert-written content, cycle-trend analysis and the doctor's report are held back for Flo Premium, whose exact price is not published as a flat figure and instead varies by region, platform and ongoing promotions.
- Given how sensitive cycle and fertility data is, anyone using the app should read Flo's own privacy settings — including Anonymous Mode, which strips the account from directly identifiable personal data — rather than assume the defaults match their comfort level.