Study Uncovers Privacy Risks in Period Tracking Apps
A recent investigation by Mozilla has revealed that several widely used menstrual cycle tracking apps are sharing personal user data with advertising networks such as Google, Meta, and TikTok. The study examined six apps: Flo, Clue, Stardust, Spot On, Period Calendar, and Euki. Stardust performed the worst, transmitting detailed reproductive health information—including data on pregnancy, contraception, mood, alcohol use, and specific symptoms—to RudderStack without disclosing this practice in its privacy policy.
Many of the apps tested send basic identification numbers to platforms like Google, Meta, Microsoft, and TikTok. For instance, Period Calendar shares device identifiers and information with Google and InMobi, with no option to disable this sharing. Similarly, the Planned Parenthood website behind Spot On transfers data to Google, Microsoft, TikTok, and Pinterest without offering an opt-out. Flo and Clue, on the other hand, do not share health data with third parties but do report app usage—though this can be turned off. However, these two apps collect more health-related data than others, storing it on their own servers.
Safer Alternatives and Ongoing Privacy Concerns
The only app recommended without reservations was Euki, which stores all health data exclusively on the user's device. Euki requires no account creation and includes a decoy feature that displays fake information, enhancing its privacy protections. In 2021, Flo settled a case with the U.S. Federal Trade Commission (FTC) over data sharing with Meta and Google. In 2022, an investigation found that lists of devices using Clue, Period Calendar, and other apps were being sold online.
"Users deserve better—and at the very least, they should understand what is really happening with their data."
Shoshana Wodinsky
Sarah Heggan added, "The mere act of using a reproductive health app can have consequences—like tipping off law enforcement to where they can find a valuable trove of health data." She also emphasized, "People have reason to be concerned, living in a world where pervasive surveillance is combined with the criminalization of abortion in parts of the United States."
This research raises serious questions about the privacy and security of reproductive health data, especially in light of recent legal changes in the U.S. With increasing scrutiny over personal data and growing attention to women's rights, these findings may prompt users to reconsider their use of such apps and become more vigilant about privacy issues.
As concerns over user privacy continue to grow, the need for enhanced protections against data misuse is becoming increasingly evident. This is particularly relevant in the context of the recent calls for tighter safeguards against intimate deepfakes, which highlight the broader implications of data security in digital platforms. Understanding the risks associated with personal data sharing is crucial for users of various applications, including menstrual tracking tools.