Body Composition · GLP-1
GLP-1 Muscle Loss Risk Calculator
Calculate your risk of losing lean muscle on Ozempic, Wegovy, or tirzepatide — and get a personalised protein target and exercise plan to protect it.
💪 Semaglutide & Tirzepatide
📅 Updated May 2026
🆓 Free, no sign-up
Why muscle loss matters on GLP-1
GLP-1 medications produce rapid weight loss — but without proper intervention, a significant portion can be lean muscle rather than fat. Clinical trial data shows approximately 25–40% of total weight lost on semaglutide without additional intervention is lean mass. This matters beyond aesthetics: muscle drives your resting metabolic rate, and losing it makes weight maintenance harder after treatment ends.
The good news is this is largely preventable. Patients who combine adequate protein intake with resistance training preserve an estimated 10–15% more lean mass, shifting the muscle/fat ratio significantly in the right direction.
Key principle: Protein and resistance training are non-negotiable during GLP-1 treatment, especially in months 1–6 when weight loss is fastest and muscle loss risk is highest.
The protein target explained
This calculator uses goal body weight rather than current body weight for the protein calculation. As you lose weight, protein needs decrease — basing targets on goal weight gives a more sustainable long-term number that doesn't require constant recalculation. The target range (0.7–1.0g per pound) reflects different need levels. Older patients, those losing weight rapidly, and those doing significant resistance training benefit from targets at the higher end.
The four risk factors
Your retention score is based on age (sarcopenia risk increases after 50), protein intake relative to body weight (the primary driver of retention), resistance training frequency (2–3x per week is the evidence-based threshold), and rate of weight loss (faster loss correlates with higher lean mass loss). Each factor is weighted based on its relative contribution in the published literature.
Frequently asked questions
Do you lose muscle on Ozempic or Wegovy?+
Yes, some muscle loss is common on GLP-1 medications. Clinical trial data shows approximately 25–40% of total weight lost on semaglutide without additional intervention is lean mass. However, this can be significantly reduced to 15–25% with adequate protein intake (0.7–1.0 grams per pound of goal body weight) and regular resistance training two to three times per week. Patients who maintain protein targets and strength training preserve an estimated 10–15% more lean mass than those relying on medication alone.
How much protein do I need on GLP-1 to preserve muscle?+
Most GLP-1 clinicians recommend 0.7 to 1.0 grams of protein per pound of goal body weight per day while on semaglutide or tirzepatide. This is significantly higher than general guidelines because GLP-1 medications suppress appetite so effectively that calorie intake often drops 30–50%, creating risk of muscle loss without intentional protein targeting. For a 200-pound person targeting 160 pounds, that's 112–160 grams of protein daily.
Does resistance training prevent muscle loss on GLP-1?+
Resistance training two to three times per week significantly reduces muscle loss during GLP-1 treatment. Studies show patients who combine resistance training with adequate protein preserve approximately 10–15% more lean mass than those on medication alone. Cardio alone does not protect lean mass as effectively. Compound movements — squats, deadlifts, rows, presses — are most effective because they stimulate the largest amount of muscle tissue.
What is a good muscle retention score?+
A score of 75 or above is considered good during GLP-1 treatment, indicating low risk of significant lean mass loss. Scores above 85 are excellent and reflect optimal protein intake, regular resistance training, and moderate weight loss pace. Scores below 60 indicate elevated risk and warrant immediate dietary and exercise adjustments.
Is creatine helpful on GLP-1 for muscle preservation?+
Yes. Creatine monohydrate at 3–5 grams daily has emerging evidence for lean mass preservation during GLP-1 treatment. It supports muscle protein synthesis, reduces muscle breakdown during caloric restriction, and has an excellent safety profile. Several GLP-1 clinicians now routinely recommend creatine alongside resistance training as a muscle protection strategy.