CinderTerms of Use
Last updated September 30, 2026
Cinder is not medical advice. It tracks fasts and food and explains what's known about them. It doesn't know your health history. Talk to a clinician before fasting beyond a normal overnight window, and stop and get help if you feel unwell.
Who can use Cinder
You must be 18 or older. By using Cinder you agree to these terms and to the Privacy Policy.
Health information
- Science content summarizes published research and says how strong the evidence is. It can be incomplete or change as research changes.
- Calorie burn, energy balance and photo food estimates are estimates and can be wrong. Food values from databases and barcodes can be wrong too.
- Ash-ly and the meal chef are generated by AI. They can be wrong, and they aren't a substitute for a doctor, dietitian or pharmacist.
- Extended fasting is unsafe for some people, including anyone who is pregnant or breastfeeding, has type 1 diabetes or takes insulin, a sulfonylurea or an SGLT2 inhibitor, has a history of an eating disorder, or has kidney, liver or heart disease. The app lists these when you start.
Your account and friends
- Keep your email secure; anyone with access to it can sign in.
- Be kind in encouragement notes. Don't use Cinder to harass anyone, share anything illegal, or impersonate someone.
- Referral bonuses are one per person, within your first 14 days, and can't be traded back and forth.
- You can delete your account in the app at any time.
Cinder Pro
Some features are marked Pro. They're free for everyone during the beta. If paid plans are introduced, prices and terms will be shown before you buy, and purchases in the iPhone app go through Apple. Safety information is always free.
Acceptable use
Don't try to break, overload or reverse-engineer the service, get around usage limits, or access other people's data.
Your content
You own what you log and write. You give us permission to store and deliver it only as needed to run the features you use, as described in the Privacy Policy.
Availability and changes
Cinder is offered as is and may change. We may update these terms; if the change matters we'll tell you in the app, and continuing to use Cinder means you accept the new terms.
Disclaimers and limits
To the extent the law allows, Cinder is provided without warranties, and we aren't liable for indirect or consequential damages or for decisions you make based on the app. Nothing here limits rights you have under consumer protection law.