The scale can't tell you what you're losing.
On a GLP-1, appetite drops fast and protein usually goes with it. Sustain tracks your dose, your protein and your weight in one place, so the number going down never hides the one that shouldn't.
Manual logging is free forever. No trial, no card.
Nobody decides to lose muscle. It just isn't the thing being measured.
Rapid weight loss without enough protein costs you lean mass as well as fat. Most of the time the sequence looks like this, and every step of it feels like progress.
The dose goes up
Titration is working exactly the way it's supposed to.
Food stops appealing
Half a plate is plenty. Dinner gets skipped without much thought.
Protein drops first
It's the hardest thing to eat when nothing sounds good.
The body makes up the difference
Some of it comes from muscle. The scale reads it as a good week.
The same twelve weeks
One line down. Made of what?
The bracketed drop in the lean mass line is the part of the loss that wasn't fat.
You can't fix what you can't see. So the first thing Sustain does is make it visible.
Everything on one screen.
Your next dose, today's protein against a target set for your body, and where your weight is actually heading.
Point it at dinner.
Photograph the plate and Sustain estimates the protein. No database, no portion maths, and you can edit the number.
Two lines, not one.
Body fat and lean mass tracked separately, so a falling number finally tells you what it was made of.
It answers from your data.
Not the internet's. It never diagnoses, never reads a lab value and never suggests a dose.
Bring your bloodwork in.
Photograph a report and Sustain transcribes the values for you to review. Interpretation stays with your prescriber.
Every other tracker was built around the scale.
The parts people ask about first.
"Free" usually means free for a week.
Not here. Logging your dose, weight, protein and side effects is free forever, with no card and no countdown. Sustain+ unlocks the AI features and your full history. That's the whole split.
Where does my health data go?
To your own account, protected so only you can read it. It is never sold, never shared with advertisers, and never used to train an AI model. You can permanently delete the account and its data from inside the app.
Is this giving me medical advice?
No, deliberately. Sustain never diagnoses, never interprets a lab value and never suggests a dose change. It transcribes, tracks and shows you patterns. Every clinical decision stays with your prescriber.
Does it work with what I already use?
Weight and protein sync both ways with Apple Health, so you're not logging the same thing twice. There's a Lock Screen widget, a Live Activity and an Apple Watch complication for logging a dose in one tap.
Manual logging is free. That isn't a trial.
- AI photo protein estimates
- Full history and trends
- Weekly AI recap
- Side-effect pattern reports
- Body composition and lab import
- Everything in annual
- Cancel anytime
- A range to hold, not a number to chase
- A prescriber conversation guide
- One-time purchase, no new subscription
Start with tonight's dinner.
Log one plate, one dose, one weigh-in. That's enough to start seeing the second line the scale never showed you.
Sustain is a tracking tool, not a medical device. It never diagnoses and never suggests a dose change.