A period tracker knows when you have sex, when your period is late, your moods, your symptoms and sometimes your temperature. That's some of the most sensitive information on your phone. Since the US Supreme Court's 2022 decision in Dobbs v. Jackson, a lot more people have started asking where that data goes.
Privacy policies are long, but you only need answers to seven questions. Here they are, with the answers for SheSync, which we make, so you can see what good answers look like. Our full privacy policy has the detail.
1. Where is my cycle data stored?
This is the most important question. Data that only exists on your phone can't be leaked from, sold by or handed over by the company, because the company doesn't have it. Data on a company's servers is only as safe as that company.
SheSync: on the free plan, everything you log stays on your phone and is never uploaded. If you subscribe to SheSync Pro, your logs are also backed up to encrypted cloud storage so your history follows you to a new phone. The trade-off is stated plainly: on the free plan, if you lose your phone, that history is gone.
2. Is my data sold, or used for advertising?
Look for a clear "we don't sell your data" and "we don't use advertising networks". Vague phrases like "trusted partners" deserve a closer look.
SheSync: no selling, no advertising networks, and no tracking you across other apps or websites.
3. If there's an AI feature, where do my messages go?
AI features are new in period trackers, and many apps send your questions to a third-party AI company. Ask which company, whether your messages are stored, and whether they're used to train models.
SheSync: the AI assistant runs on servers we operate, and messages are not sent to OpenAI, Anthropic, Google or any other AI company. Your conversations are stored only on your phone. When you send a message, it's used to generate the reply and then discarded, and it's never used to train AI. You can also switch off the setting that lets the AI see your cycle data.
4. Who can see my cycle besides me?
Sharing features are great, as long as they're off by default and fully under your control.
SheSync: nobody, unless you send an invite and the other person accepts. They see your cycle phase, predicted dates and logged symptoms, never your AI conversations. You can remove them at any time.
5. What ends up in crash reports and analytics?
Apps collect diagnostic data to fix bugs, and sloppy ones leak health details into it.
SheSync: crash reports are built to strip out cycle and symptom details before they're sent.
6. Can I actually delete everything?
Deletion should be a button, not an email chain, and it should remove data from the company's servers, not just your phone.
SheSync: Settings → Delete Account removes your account and your cycle history from our servers automatically, and clears the data on your phone. You can also request it on our account deletion page.
7. Is the privacy policy readable?
A company that respects your privacy explains it in plain language. If you can't tell what happens to your data after ten minutes of reading, that's an answer in itself.
A quick checklist
- Health data stays on your device, or is encrypted if backed up
- No selling, no ad networks, no cross-app tracking
- AI features name who processes your messages, and don't train on them
- Sharing is off by default and revocable
- Deletion is in the app and actually removes server data
- The privacy policy is written for humans
Whatever app you choose, it's worth five minutes with these questions. If you're choosing a tracker to share with a partner too, see our comparison of period trackers for couples.
Frequently asked questions
What is the most private period tracker app?
The most private trackers keep your cycle data on your phone rather than on company servers, don't sell data or use ad networks, and let you delete everything from inside the app. SheSync keeps free-plan logs on your device only, runs its AI on its own servers without sending messages to other AI companies, and has in-app account deletion.
Does SheSync sell my data?
No. SheSync does not sell your personal information, does not use advertising networks and does not track you across other apps or websites.
Is my period data stored in the cloud with SheSync?
On the free plan, no: your logs stay on your phone only. With SheSync Pro, your logs are also backed up to encrypted cloud storage so your history survives a new phone. Your AI conversations are never stored in the cloud on any plan.
Does the SheSync AI send my messages to OpenAI or other AI companies?
No. The SheSync AI assistant runs on servers operated by SheSync's developer. Messages are not sent to OpenAI, Anthropic, Google or any other AI company, are discarded after the reply is generated, and are never used to train AI models.
Last updated 29 September 2026. SheSync is a tracking and education tool, not a medical device or contraceptive method. For medical questions about your cycle, talk to your doctor.