# Hormetic

> Hormetic is a wellness tracker for iPhone and Apple Watch that logs sauna, cold-plunge, and hot-tub sessions as HealthKit workouts and estimates a dose for each — on three separate, independently versioned algorithms. Every algorithm-derived value is labeled "Estimated." Heart rate is measured; temperature is entered by the user (or read from Apple Watch Ultra's water-temperature sensor for plunges and soaks). Nothing leaves the device. It is not a medical device.

Key facts
- Publisher: Avesta Forge LLC (Texas, US) · https://avestaforge.com
- Price: $2.99, one-time. No subscription, no in-app purchases, no account.
- Requires iOS 18.6 or later. Apple Watch optional (heart rate). Apple Watch Ultra adds automatic submersion detection and water-temperature sensing for cold plunges and soaks.
- App Store: https://apps.apple.com/us/app/hormetic/id6766344765
- Current version: 1.6.5 (released 2026-08-24). The v1.6 line is "Spa Mode": hot tubs and hot baths added; cold plunge added in 1.5; sauna/steam/infrared since 1.0. 1.6.5 added cold and hot-water sections to the Learn tab with cited explainers, a sessions-per-week Adapt chart, swipe-to-delete for sessions, and discards accidental sub-7-second starts.
- Privacy: no accounts, no analytics, no telemetry, no third-party SDKs; sessions stored on-device in HealthKit.
- Device safety: Hormetic never asks you to put an iPhone or Apple Watch in a sauna. In a sauna, temperature is entered by hand and the Watch contributes heart rate only. Cold plunges and hot tubs are shallow-water immersion; the app's in-app guidance caps a soak at 40 °C (104 °F).
- Science: every health claim on the site links to a PubMed source and is framed as association, not causation. The name refers to hormesis; the app estimates where a session sat in a useful range and does not measure any molecular event.

## Pages
- [Home](https://hormetic.app/): the app, three modalities, zones, science with citations, privacy, safety, FAQ
- [Full text for LLMs](https://hormetic.app/llms-full.txt)
- [Privacy Policy](https://hormetic.app/privacy)
- [Support](https://hormetic.app/support): support@hormetic.app

## Optional
- [Avesta Forge LLC](https://avestaforge.com/): the studio behind Hormetic