# The privacy problems hidden in your period tracker

> **Open Intelligence Dossier** · First detected: 2026-07-16 17:07 UTC · Category: Technology

## Executive Summary
Mozilla research reveals hidden privacy risks in period tracking applications, highlighting Stardust's data sharing practices.

## Intelligence Brief
Recent coverage from multiple outlets, including CyberInsider, FemTech World, SC Media, All About Cookies, The Tech Buzz, The News International, Yahoo Tech, and the BBC, highlights significant privacy problems associated with menstruation tracking applications. According to the reporting, a new study published by Mozilla evaluates the privacy practices of various period tracking apps. The findings specifically center on the application known as Stardust, which researchers discovered has been sharing sensitive user health data with third parties, including an analytics firm. Outlets such as SC Media and Yahoo Tech heavily emphasize the specific risks discovered during the research, noting the contrast between applications regarding data protection.


While the reports detail how Stardust allegedly compromised user privacy by transmitting personal health information to external entities, other applications were evaluated differently in the same study. CyberInsider specifically notes that Mozilla's study ranked Euki as the most private period tracker currently available, providing a benchmark for user privacy in the digital health sector. The broader context provided across these reports addresses growing concerns regarding digital menstruation trackers and the security of sensitive personal information. Users often input highly intimate health data into these applications, expecting strict confidentiality.


However, as highlighted by The News International and All About Cookies, the hidden privacy risks mean that platforms promising privacy may actually be sharing intimate health details. This brings renewed scrutiny to the femtech industry and the handling of personal data by mobile applications. Coverage does not yet specify what legal or regulatory actions may follow the Mozilla study findings, nor does it detail any official response from the developers of Stardust. Future updates will likely track whether users abandon the application in favor of highly ranked alternatives like Euki, and whether regulatory bodies will investigate the data-sharing practices uncovered by the researchers.

## Multi-Source Evidence Table
| Source Outlet | Headline | Verification URL |
|---|---|---|
| CyberInsider | Mozilla study ranks Euki as the most private period tracker | [Source Link](https://news.google.com/rss/articles/CBMijgFBVV95cUxPcVZERXZ6U1NvYVRtOUY1MTh6eVZhd1lXSG5BZUpiLVNOUTJBREdXZ204Um5NM3hqUEZLWnVYSm9wallFOEdDTHYyZVZzY3dtTU5ibU94eUxac05pWksyTWw2TGROZmNLVVdJbExYdjllLW00Vm40dS02ZHhLeVJ1bG13c2J1b0J3TElhVW5B?oc=5) |
| FemTech World | Stardust period tracker shares health data, study reveals | [Source Link](https://news.google.com/rss/articles/CBMirgFBVV95cUxNN3BGTGFINXlVLWhzOXhyelRmeW9abFFlUDdLVV9oQm9QOS1fTW55TmZGa2FTWWpzZzN3LUNTQnVwWWFMWEgtSXRTdDcwbzJ3SDl3SnNSZjJyWEVmLVRYMmdWVDgydEF6Wk5Uc093NFRsWlJnZXROV0pEeXpFSndaTF85NzhESDYtWVhDYTUzOFlSdms2RGQ5NFMwa2hqNkdWdDg1dDlwOXNvU3lUeGc?oc=5) |
| SC Media | Period tracking app Stardust shares sensitive user data with third parties, report finds | [Source Link](https://news.google.com/rss/articles/CBMiuAFBVV95cUxNT0VKTnpodk5ySzdqX2pJM3NJb01JblY5VUF3d3pITU1VLXQ2Q3RzUUZBSHQ5a1VMWHF0ZVRDWEF1bmRpd1c3Y2ltU1RQR1BRLXVrYmxvNjcwc0hnZGhmNXlYdnZVb1JUYjFNU0hjTURvY3VyampDQXZIbkNHZWFuRXpxYWZWT196ZG1YeEI0Uk5Lem41NkVYRXMyTnBLNG5zNWd3Nnl0MVFvNFo5Rm5GX09FM3NHYWFY?oc=5) |
| All About Cookies | This Period Tracker Promised Privacy. Researchers Say It Shared Users’ Health Data Anyway | [Source Link](https://news.google.com/rss/articles/CBMibkFVX3lxTE43TmJzbWVvdmpaQWpWQk1tcUFsQzhOdWo1WEZWdGM4a2FpVVZINjdKRkQwcmNITnhaNmFGYWpDTnVpUUtHNHpnY1ZoSUhGMmctbWdhLXRmcXFrZmNTU1lzSzBUQmtNa25yTnh6Z0Jn?oc=5) |
| The Tech Buzz | Stardust Period Tracker Caught Sharing Health Data in Mozilla Study | [Source Link](https://news.google.com/rss/articles/CBMiogFBVV95cUxNVktybGRKMktycW5VdDJNQUJ6YUUtUjZZeUtGalFyQUlzRFBCMnl1UjRJc2tJOWFUSlRMMWNnUG1DX0ctVlBHbFBvUEVrMFhBOE9seGZtRWZRQ1lyYThmMGsyVmFvRjdDM1ZlVGdSYWRSS0FjTUlhOTNRaUNRT2RObFBCTlZYaUpQalc4cFdTY2I3VUQyZ2syeTVQSUpyLUE2RXc?oc=5) |
| The News International | Your menstruation tracker may be sharing more than you think: Hidden privacy risks | [Source Link](https://news.google.com/rss/articles/CBMipAFBVV95cUxObTlGX3IxWFNIVnRmZndROFlidWEzaFlrdVZqeXc4VGtORVV4MllzVTQxY2RmczNWN0JveTFqb3lsSjByaXNuZTU3aWpEMXJOQTM5Q0RwZUVFMGxRakFJSWRFUTZzTjFKa2F4bUdLejIwQnRDZGFVeUFxUkpaWXJfaXlOT1RjMEo5bGM0Wkd1X3JKaTlJZ0FOSkpqUVpocGxLTTUxdg?oc=5) |
| Yahoo Tech | Period tracker Stardust shares users’ health data with analytics firm, says Mozilla research | [Source Link](https://news.google.com/rss/articles/CBMingFBVV95cUxNYUFRaU5WdW9aQXB3dFVIYUZuUDROdWxtc1I3RElsODFZajRJRFE2UUlBX1UwczBVTlJkdV9pcURFdk5nbzBSVVhZZHZRSUU1dlY0OEZMalptVnVNdU9JZ0ZzSVRXcW8xMEZOZm9VeWlKa29ObVBwRDEyNlpHUlVuTGRwTUVWeVhsYmhfSEJNMEs1M0htN1QtNjJBWW5Bdw?oc=5) |
| BBC | The privacy problems hidden in your period tracker | [Source Link](https://news.google.com/rss/articles/CBMilwFBVV95cUxQTERMc0dOcmJib0hZdy1fNkNjVkRrUUozZGUxZ24yUnVXZ1FLM0ZFZ1lDejFJTXA5Q2dvQ1ZSallDcmlaaDFlQ0pxYTVtMjRacWdaTTk4U3VxVWtkOWtkcUpiblRJQU43akNVeXNnbm5GRFpKUldKNUVzNzM1Uzc0SV93NVJuMTRiUkExcHVtNlRWbE9xc3Rn?oc=5) |

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*Canonical Source: https://pulse.byoviral.com/trend/2026-07-16/the-privacy-problems-hidden-in-your-period-tracker*