Key to Health is designed for high-achieving, busy people who want to look better, feel better, and optimize their long-term health without spending hours on complex routines.

Backed by science. Guided by AI. Built for real life.

Our breath sensor gives you real-time feedback on your body's fat metabolism—so you can see what your daily choices are actually doing, not just hope for the best. Pair that with smart AI coaching, and you have a system that adapts to you.

What you'll get:

Real-time fat metabolism tracking with our breath acetone sensor

Personalized coaching from Key, your AI health guide

Clear, science-based goals and progress tracking

Tools to build strength and support long-term health

Eat what you love—no restricted foods, no keto required

Meet Key: Your 24/7 AI Coach

Key learns from your habits, adjusts your plan, and guides you every step of the way. Instant support and personalized guidance, whenever you need it.

Grounded in clinical evidence. In a published clinical trial, participants following the Key to Health program lost an average of 10% total body weight over 48 weeks.

No fad diets. No extreme routines. No forbidden foods. Just real progress, made easy.

This app and breath monitor are for adults 18 years and older.

Subscription pricing and terms:

Key to Health offers an auto-renewing monthly subscription at $49.99/month to provide you with unlimited access to the Key to Health Premium collection while you maintain an active subscription.

Payment will be charged to your Apple Account when you confirm the initial subscription purchase. Subscriptions automatically renew unless auto-renew is turned off at least 24 hours before the end of the current subscription period. Your account will be charged for renewal within 24 hours prior to the end of the current period at the current subscription price. You may manage your subscription and turn off auto-renewal by going to Settings > Manage Subscription on your device after purchase. Any unused portion of a free trial period, if offered, will be forfeited when you purchase a subscription, where applicable.

Read more about our terms and conditions here: