How Zella handles your teen's health data
What Zella tracks, if your teen turns it on
- Period tracker with cycle predictions
- Headache tracker with triggers and patterns
- Mood check-in (1 to 5 faces)
- Energy slider (1 to 10)
Where that data lives
On your teen's device only. Not on Zella's servers. Not accessible to us. Not visible to parents or schools unless your teen generates a report and shares it directly.
Because Zella is a web app installed to your home screen rather than a traditional app store download, your health data is stored in your browser's private storage. This storage is not included in iCloud backups, Google backups, or any cloud sync. Apple and Google cannot access it. Neither can we.
What happens if my teen deletes the app
All health data is deleted with it. We never had it. There is nothing to retain. Your teen can save a private backup file anytime from Profile → Back up, so switching phones never means losing their history.
Can my teen share their health data with me or a doctor
Yes, if they choose to. Your teen can generate a PDF health report from inside their own dashboard and share it with anyone they choose. This is always their decision, never automatic.
Sharing with a parent works through two separate controls, and your teen turns each on or off independently in their own settings: sharing the academic calendar, and sharing a weekly health summary (which days had a headache or a period, yes or no, nothing more). One never requires the other. Your teen can share the calendar without the health summary, the health summary without the calendar, both or neither. They can change their mind at any time.
Why we built it this way
We built Zella for a neurodivergent teen who needed to track her own health patterns to understand how her body affects her school performance. We knew from the start that if a teen suspected anyone could see her health data she would never log it honestly. The data is only useful if it is completely private.
But there is something bigger here too.
Health data is among the most personal information a person generates. Period cycles, headache patterns, mood fluctuations, energy levels. This is intimate data that has real consequences when it ends up in the hands of companies, insurers, advertisers, or data brokers. We have watched the health data industry grow into something most people would not have consented to if they had understood what they were agreeing to. A teenager should not have to navigate that. Her health is hers.
So we built it differently. Your teen's health data never leaves her device. It never touches our servers. We cannot sell what we never have. We cannot share what we cannot see. No algorithm will ever target her based on her cycle. No insurance company will ever see her headache logs. No advertiser will ever know her mood scores.
This is not a privacy policy promise that can change when a company gets acquired or when a terms of service update goes unread. It is how the app is technically built. The data does not go anywhere because we designed it so it has nowhere to go.
We think that is how all health technology for young people should work. We built Zella to prove it is possible.