comparisons

Flo vs Natural Cycles: FDA Contraception or Free App (2026)

Flo: free, $59.5M settlement for sharing data with Facebook. Natural Cycles: $99.99/yr, FDA-cleared as birth control. Both store cycles on servers.

Two different products competing in the same category Flo is a general purpose period and symptom tracker. Natural Cycles is an FDA cleared contraceptive device that happens to be an app. Comparing them requires understanding that distinction. If contraception is your primary goal, Natural Cycles is the only app in this category with FDA De Novo clearance for contraceptive use. That clearance means the FDA reviewed clinical evidence for effectiveness, something no other period tracker has done. The trade off is cost ($12.99/mo) and daily commitment (basal body temperature every morning before getting up). If general cycle tracking and symptom logging is your goal, Flo's free tier covers the basics. But Flo's data practices are a documented problem. The FTC found in 2021 that Flo shared health data with Facebook, Google, and Flurry without user consent. A class action over the same conduct settled for $59.5M in September 2025 (Reuters 2025 09 25). The privacy gap neither closes Both Flo and Natural Cycles require an account. Both store your data on company servers. Neither offers on device only architecture. This matters because server side storage means data exists somewhere that c