What we can and can't see
Our privacy promise and terms of use. Last updated July 13, 2026.
What stays on your device
Everything you log: temperatures, cervical fluid, flow, intercourse, test results, moods, symptoms, and notes. All of it is stored in your browser's local database on your phone or computer. Saving an entry makes zero network requests. You can verify this yourself with your browser's developer tools, and we encourage you to.
What our servers can see
Three things, and only three. Your email address and login session, handled by Supabase, our authentication provider. Your goal setting and timezone, so the app greets you correctly. And if you turn on optional sync: encrypted copies of your entries that we cannot read. Sync data is encrypted on your device with a passphrase only you know before it is uploaded. What sits on our servers is ciphertext. We do not have the key, and neither does anyone who might compel us to produce your data.
The AI insight feature
When you tap "Explain my chart," we send only the computed summary (your coverline value, estimated ovulation day, fertile window dates, and confidence level) to Anthropic's Claude API to generate the plain-language explanation. Your raw daily log never leaves the device. We do not store the summary or the response on our servers, and Anthropic does not train models on API data.
Sharing with a mentor
If you connect with a mentor and choose to share a chart, that specific snapshot (the cycle's entries and computed summary) is uploaded to Lutaria so your mentor can view it, and chat messages between you are stored on our servers. This is the only health data that ever reaches us, it happens only through your explicit action, and you can delete any shared chart or end the mentorship at any time; deletion is immediate. Mentors agree to treat everything you share as confidential, and mentoring is charting support, never medical advice.
The assistant and feedback
The optional AI assistant runs only when you send it a message. It receives your recent cycle summaries (computed on your device) and your question, never your raw daily notes, and we do not store the conversation. When you send feedback, your message and email are saved so we can read and act on it. Neither feature ever runs on its own.
Analytics
Today: none. No analytics scripts, no ad SDKs, no trackers, no fingerprinting. If we ever add product analytics, it will be privacy-respecting and aggregate (counts of feature usage, never the content of anything you log), we will name the provider here, and we will update this page before it ships, not after.
Sync recovery
Because sync is end-to-end encrypted, a lost passphrase means the synced copy is unrecoverable. That is the design working as intended: recovery paths for us would be back doors for everyone else. Recovery codes (a one-time code you store somewhere safe) are on our roadmap; until then, your local data and your JSON exports are unaffected by a lost sync passphrase.
Export and deletion
Your data is yours. Export it as JSON or CSV anytime from Settings. Delete everything on your device with one tap. If you use sync, "Disable & delete server copy" removes every encrypted blob from our servers immediately. Deleting your account removes your email and profile from Supabase.
Terms of use
Lutaria is an educational tracking tool, not a medical device and not medical advice. The charts, predictions, fertile-window estimates, and AI explanations are derived from data you enter and from established fertility-awareness rules, but they are estimates. Bodies vary, cycles vary, and data entry is imperfect.
Lutaria is not a contraceptive. It has not been cleared or approved by the FDA or any regulator for pregnancy prevention. If avoiding pregnancy matters to you, do not rely on this app alone; fertility-awareness methods require proper instruction and consistent practice, and their real-world effectiveness depends heavily on correct use. Talk to a healthcare provider or a certified fertility-awareness educator about methods appropriate for you.
Trying to conceive is not guaranteed either. If you have been trying for twelve months (or six months if you are 35 or older) without success, current guidance is to talk with a doctor; the app will never be a substitute for that conversation.
By creating an account you confirm you are at least 16 years old, you accept these terms, and you understand the privacy model described above. We may update this page; material changes will be shown in the app before they take effect.
Questions
Email privacy@lutaria.com. We read everything.