How much of my GLP-1 weight loss was muscle?
Enter your weight and body fat from when you started and from today. The calculator splits what you lost into fat and lean mass and sets it beside what the trials measured. Nothing is stored, and no account is needed.
Fill in both readings to see how the loss splits between fat and lean mass.
Smart scales estimate body fat by impedance, which shifts with water, meals and time of day. Compare readings at least two weeks apart, taken at the same time of day. This is a scale estimate, not a DEXA scan.
Why lean loss matters on a GLP-1
Any large weight loss takes some lean mass with it: muscle, but also water, organ tissue and bone. GLP-1 medications are no exception. In the DXA sub-studies, roughly a quarter (tirzepatide, SURMOUNT-1) to two-fifths (semaglutide, STEP 1) of the weight lost was lean. Muscle carries strength, balance and blood-sugar handling, so a share well above that range is worth noticing, especially later in life.
How to protect it
- Protein: aim for the range shown above, spread across meals. With a smaller appetite, protein first at each meal helps.
- Resistance training: two or three sessions a week of anything that loads your muscles (weights, bands, bodyweight) is the strongest signal to keep them.
- Measure on a schedule: same scale, same time of day, at least two weeks apart. Single readings bounce.
When to talk to your clinician
If your lean share stays above 40% across several readings, if you feel weaker or less steady, or if you are losing weight very fast, bring it up at your next visit. They can order a DEXA scan, review your dose pace, or refer you to a dietitian.
Track it automatically
SteadyRange's muscle-loss check uses every scale reading, so the split updates as you go and lands in the report you bring to your clinician.
General information, not medical advice. Smart-scale body fat is an impedance estimate, not a DEXA scan. For the weight curve itself, see the GLP-1 weight loss calculator.
See your own curve, not just clinical trial averages
Trial curves show the population average. SteadyRange records your actual weekly doses, weigh-ins, and fasting blood sugar together so you and your prescriber see how your body steadies over time, on a private log you control.