# Adenal

> Adenal is a free caffeine and sleep tracker for Android, iPhone and Apple Watch, made by Aralel GmbH in Aachen, Germany. It estimates how much caffeine is in your body right now, tells you when it is safe to sleep, and shows how the timing of coffee, tea and energy drinks affects your own sleep.

Key facts:

- Caffeine model: first-order absorption and elimination, summed over all drinks of the last 48 hours. Default half-life 5 hours (fast 3 h, slow 7 h or custom), absorption rate 4 per hour.
- Sleep line: 50 mg by default. Safe-to-sleep time is when the level drops below it and stays there. Last-coffee cutoff is the latest standard cup that still leaves you under the line at bedtime.
- Logging: one-tap Coffee (95 mg) and Tea (47 mg), more than 20 built-in drinks, favourites, custom drinks, barcode scanning (Open Food Facts), widgets, Lock Screen, Control Center, Siri and Apple Watch.
- Sleep: going to bed is recorded separately from falling asleep; nights and naps are recorded on a timeline; motion-based sleep suggestions are confirmed by the user; sleepiness is logged on a 1–5 scale.
- Insights: after 14 recorded nights, caffeine at bedtime is compared with sleep duration, time to fall asleep, sleep rating and sleepiness; weekly summary and streaks.
- Privacy: works without an account, data stays on the phone; motion data never leaves the device; an optional account (Sign in with Apple or email code) syncs data; caffeine and sleep data is never shared with advertisers; export and deletion in the app or on the website.
- Price: free, with a small ad banner (Google AdMob, non-personalized by default).
- Not a medical device; values are estimates.

## Download

- [Adenal on Google Play](https://play.google.com/store/apps/details?id=com.aralel.adenal): Android app
- [Adenal iPhone beta on TestFlight](https://testflight.apple.com/join/BPc2Y7Sj): iPhone and Apple Watch (install Apple's TestFlight app first)

## Pages

- [Home](https://adenal.aralel.com/): overview, example caffeine day, usage totals
- [How to use Adenal](https://adenal.aralel.com/help): step-by-step guide to logging drinks, recording sleep and reading insights
- [FAQ](https://adenal.aralel.com/faq): common questions
- [Privacy policy](https://adenal.aralel.com/privacy): what data is processed, legal bases (GDPR), rights
- [Terms of use](https://adenal.aralel.com/terms)
- [Delete your account](https://adenal.aralel.com/delete-account): delete an account and all synced data without the app

## FAQ

### Is Adenal free?

Yes. Adenal is free and shows a small ad banner on the Today, History and Insights screens. Ads are not personalized unless you turn that on in Settings → Privacy.

### How does Adenal estimate the caffeine in my body?

Each drink is absorbed over the first hour or so and then broken down at a steady rate. Adenal adds up every drink from the last 48 hours using your caffeine half-life: 3 hours (fast), 5 hours (normal, the default), 7 hours (slow) or your own value. Half-life varies a lot between people, so the result is an estimate, not a measurement.

### What is the sleep line?

The amount of caffeine below which you are likely to fall asleep without trouble. It is 50 mg by default; change it in Settings → Limits. Safe-to-sleep time is when your level drops below this line and stays there.

### Do I need an account?

No. Without an account everything stays on your phone. An account (Sign in with Apple or email) backs up your data and syncs it between your devices.

### Why is going to bed recorded separately from sleep?

Lying in bed is not the same as sleeping. Recording both shows how long it takes you to fall asleep, which caffeine affects most.

### How does sleep detection work?

Your phone's motion sensors show when it lay still for a long time. Adenal suggests that period as sleep and you confirm, adjust or dismiss it. Motion data is processed on your phone and never sent anywhere.

### When do Insights appear?

After 14 recorded nights. Before that there is not enough data to compare nights with and without late caffeine.

### Does Adenal work on Apple Watch?

Yes. Log drinks from the Watch app or the complication, and see your current caffeine level on your watch face.

### Which phones does Adenal run on?

Android phones and iPhone, with an Apple Watch app. [Get Adenal on Google Play](https://play.google.com/store/apps/details?id=com.aralel.adenal). The iPhone app is in beta: install Apple's TestFlight app, then [open the TestFlight invite](https://testflight.apple.com/join/BPc2Y7Sj) on your iPhone.

### A drink I have is missing. What can I do?

Scan its barcode (packaged drink data comes from Open Food Facts) or create your own drink with its caffeine content. Brands can send their drinks to [brands@aralel.com](mailto:brands@aralel.com).

### How do I export my data?

Settings → Account → Export my data. You get a JSON file with every drink, sleep record and setting.

### How do I delete my account?

In the app: Settings → Privacy → Withdraw consent and delete all data. Without the app: [delete your account on this website](https://adenal.aralel.com/delete-account). Both delete your account and all synced data on our server right away.

### Is Adenal medical advice?

No. Adenal is not a medical device. Its caffeine values are estimates for everyday decisions. Talk to a doctor about sleep problems, pregnancy, heart conditions or medication that interacts with caffeine.

## Optional

- [Imprint](https://adenal.aralel.com/imprint): company details
- Contact: support@aralel.com