Period Tracker Stardust Shares Reproductive Health Data With Analytics Firm Despite Privacy Claims, Mozilla Finds

Mozilla research published July 16, 2026 found that period tracking app Stardust transmits users' birthdate, birth control type, reproductive goals, and symptoms to third-party analytics provider RudderStack, tied to a unique identifier. Stardust was the only app of six tested that shared health data externally. Its website states: "Your data is private. Period."