Privacy Policy
Who we are
Hormetic is developed and operated by Avesta Forge LLC, a company based in Texas, United States. The substance — what the app does and does not do with your data — does not change with the company behind it.
What Hormetic accesses
Hormetic is a heat, cold and hot-water exposure tracking app. Sessions are recorded on Apple Watch; the iPhone app is where you review them. With your explicit permission, requested in the app when a feature first needs it, Hormetic reads from and writes to Apple Health (HealthKit) on your devices.
On Apple Watch, Hormetic reads:
- Heart rate samples, during sessions
- Resting heart rate, read to personalize how the heat algorithm interprets your heart-rate response
- Sleeping wrist temperature, where available — measured by Apple Watch overnight and read only as a baseline reference. Hormetic never measures wrist temperature during a session.
- Active energy burned, to record a complete workout
It writes each session to Apple Health as a workout of type "Other", labeled with the kind of session (such as Dry Sauna, Cold Plunge or Hot Tub) so Apple Fitness can name it, along with the active energy for that workout. On a Watch with water-submersion sensors (Apple Watch Ultra), Hormetic also uses them, with your Motion & Fitness permission, to detect when a cold plunge or soak starts and ends and to measure water temperature.
On iPhone, Hormetic reads:
- Your Hormetic workouts, heart rate, resting heart rate and active energy, to show your Log, session details and Adapt
- Only if you turn on Sleep & HRV: sleep analysis, resting heart rate and heart-rate variability (SDNN and, where available, RMSSD) from about the last 31 days, to show descriptive observations around your sessions. These never feed a score.
- Only if you open the research comparisons: your date of birth and sex from Apple Health, to show how you compare with the people each study enrolled
The iPhone app writes nothing new to Apple Health. When you delete a session in Hormetic, it asks Apple Health to remove that session's workout, which needs your permission the first time.
Health permissions are requested on use, not on launch. You can revoke any of them at any time in iOS Settings → Privacy & Security → Health → Hormetic.
Where your data goes
Nowhere we can see it. The app has no server. There is no Hormetic backend, no remote API, no cloud sync that we operate. Your data exists only on your own iPhone and Apple Watch: in Apple Health, and in Hormetic's own storage on each device for things like your notes, goals, favorites and routines. It is encrypted at rest by Apple's standard protections and protected by your device passcode and biometrics.
If you have iCloud sync enabled for Health data in your own iCloud settings, Apple may sync your HealthKit data between your own devices, end-to-end encrypted. Hormetic's own storage is included in your device backups, such as iCloud Backup, if you use them. These are Apple features, between you and Apple. We have no access to them.
Between your iPhone and Apple Watch
Some optional features send data between your own paired iPhone and Apple Watch, using Apple's built-in connection between them. Nothing goes through a Hormetic server.
- Live view. Off by default and turned on on the Watch. While it's on, the Watch shares the running session's status, measured heart rate and Estimated score with your iPhone, which can show them in the app and as a Live Activity.
- Widgets. Off by default and turned on on the iPhone. A small snapshot of your practice (this week's minutes, dry-sauna visits and your goals) is saved for your widgets and sent to your Watch. It never includes notes, locations, raw heart-rate samples, or sleep and heart-rate variability.
- Temperature draft. When you send one, only the temperature and session type you confirmed go to the Watch, where you review it before recording.
- Favorites and routines. Only the ones you choose to keep on your Watch are sent to it.
On-device features
- Thermostat photo. If you pick a photo of a thermostat, Hormetic reads the temperature from it on your iPhone. It doesn't save the photo or the recognized text. Only the photo you pick is used, through Apple's photo picker; Hormetic doesn't get access to your photo library.
- Summaries. Optional written summaries are generated on your iPhone by Apple Intelligence's on-device model. Your data isn't sent to Apple or to us to write them.
- Notes. Notes, a place name and a feeling you add to a session are stored in Hormetic on your iPhone, not in Apple Health. They don't change the recorded workout or its score.
What we do not do
- We do not run analytics or telemetry. No Mixpanel, Firebase, Sentry, Amplitude, Crashlytics, or any equivalent.
- We do not have a server you connect to. No accounts. No login.
- We do not show ads.
- We do not include any third-party software development kits.
- We do not collect device identifiers, IDFA, or any tracking identifiers.
- We do not sell, rent, license, or trade personal information. We have none to sell.
- We do not have human reviewers or AI systems reading your data, because we never receive your data. Optional summaries are written on your iPhone by Apple's on-device model, as described above.
Sharing and deleting
Hormetic never initiates a share, upload, or transmission to anyone on its own. You can export your sessions as a JSON or CSV file from the iPhone app; an export happens only when you start it, your notes are included only if you choose, and you pick where the file is saved. After that, the file is yours and under your control. Your sessions are also visible in the Apple Health app like any other workout. When you delete a session in Hormetic, it also asks Apple Health to remove that session's workout; you can additionally delete any Hormetic data directly in the Health app at any time.
The "Estimated" labeling commitment
Hormetic computes derived values — a heat, cold or soak dose score and a zone classification. Every value derived by the algorithm is labeled "Estimated" in the interface. The algorithm is versioned and documented; each session records the version that produced its values. Historical sessions are never silently recomputed when the algorithm changes. This is not a marketing claim. It is a transparency commitment written into the app's architecture.
Children
Hormetic is rated for users 17 and older on the App Store. It is not directed at children under 13. We do not knowingly collect data from any users, including children. Heat and cold exposure carry physiological risks that are not appropriate for young children regardless of how an app is designed.
Medical disclaimer
Hormetic is a tracking and estimation tool. It is not a medical device. It does not diagnose, treat, cure, or prevent any disease. The information it presents is for educational and self-tracking purposes only. Heat and cold exposure carry real cardiovascular and other risks. Consult a physician before starting any heat- or cold-exposure protocol if you have cardiovascular conditions, are pregnant, take medications that affect heat or cold tolerance, or have any other condition that may affect your response.
California residents (CCPA / CPRA)
California residents have the right to know what personal information is collected, the right to delete it, the right to correct it, and the right to opt out of its sale or sharing. Because Hormetic does not collect or transmit personal information off your device, the practical answer to each of these requests is the same: there is no data we hold to disclose, delete, correct, or stop sharing. We do not sell personal information.
European Union and United Kingdom (GDPR / UK GDPR)
The data controller for any processing within the app is Avesta Forge LLC, located in the United States. The legal basis for any on-device processing is your consent, given when you grant HealthKit permissions, and you may withdraw that consent at any time in iOS Settings. Because no personal data is transmitted off your device or to us, the rights of access, rectification, erasure, restriction, portability, and objection have no remote data to act upon; they are satisfied locally — deleting the app deletes our local data, and HealthKit data remains under your control regardless.
Changes to this policy
If this policy changes materially, the new version will be posted at this URL with an updated effective date. If a change affects how the app handles data, the app itself will surface a notice on next launch.
Contact
Privacy questions, requests, or notices: privacy@hormetic.app. This address routes to a real human (the developer); replies come from a person, not an autoresponder.