How to Keep Muscle on a GLP-1 (Ozempic, Wegovy, Zepbound)

To keep muscle while you lose weight on a GLP-1, lift weights two to three times a week, eat protein at every meal, and track your strength, not just the scale. The medication handles appetite. It does not tell your body which tissue to keep. Training does.

GLP-1s are in the news again this week. On September 29, Lilly released an indirect comparison of Zepbound and the new high-dose Wegovy. It is company-reported data, and it is about how much weight people lost. It says nothing about what that weight was made of. That second question is the one I get asked most by people starting one of these drugs.

How much of the weight is muscle?

In the big trials, researchers scanned a subset of people to see what kind of weight they lost. In the semaglutide trial (STEP 1), about 45 percent of the weight lost was lean mass. In the tirzepatide trial (SURMOUNT-1), it was about 26 percent.

Two things matter before you panic about those numbers.

• Lean mass is not the same as muscle. It also includes water, organs, bone and the non-fat part of fat tissue. The researchers who pulled these trials together say this plainly.
• Losing some lean mass happens with any big weight loss, whether it comes from dieting, surgery or medication. The same review found the share is similar across all three.

So the risk is real, but it is not unique to the drug. And it is not fixed. What you do while the weight comes off changes what comes off.

1. Lift, even if it is light at first

Strength training is the signal that tells your body a muscle is still needed. When calories drop, a muscle you are not using is the first thing your body treats as optional.

You do not need a complicated program. Two or three full-body sessions a week, built on squats or leg presses, a push, a pull and a hinge, done with enough weight that the last few reps feel hard. Add a little weight or a rep when it gets easy. That is the whole idea.

If appetite and energy are low in the early weeks, shorten the session instead of skipping it. Twenty minutes of real work beats a perfect plan you do not start.

2. Get your protein in on purpose

The American Association of Clinical Endocrinology recommends 1.2 to 1.5 grams of protein per kilogram of body weight per day for people on obesity medications, to help preserve lean mass. For someone who weighs 200 pounds (about 91 kg), that works out to roughly 109 to 136 grams a day.

That is hard when you are not hungry. Three habits make it easier:

• Eat the protein on your plate first, before you fill up.
• Spread it across the day instead of trying to catch up at dinner.
• Keep easy options on hand: Greek yogurt, eggs, cottage cheese, a protein shake.

If you have kidney disease or another medical condition, set your protein target with your doctor or a registered dietitian, not from a blog post. The same goes for anyone who is struggling to eat enough at all.

The same AACE guidance also makes the point I make to every client on a GLP-1: protein alone is not enough. It works with the training, not instead of it.

3. Track strength, not just the scale

If the scale is dropping and your lifts are holding or climbing, you are doing this well. If the scale is dropping and everything feels heavier every week, that is a sign to look at training, protein and sleep. Write your numbers down. You will not remember them.

The short version

The medication takes care of appetite. Keeping muscle takes lifting, protein and someone checking that both actually happen. That last part is where most people fall off, and it is what we coach every day. If you are on a GLP-1 and want a plan built around it, start with our GLP-1 coaching page or take the Find Your Coach quiz.

Stay Consistent,
Brian

This article is general education, not medical advice. Talk with your prescriber before changing your diet, training or medication.

Sources for this post

• Neeland IJ, Linge J, Birkenfeld AL. Changes in lean body mass with GLP-1-based therapies and mitigation strategies. Diabetes Obes Metab, 2024 (STEP 1 and SURMOUNT-1 figures, lean mass definition, comparison with diet and surgery)
• AACE: Nutritional Considerations for Patients on Obesity Medications (1.2 to 1.5 g/kg/day, protein alone not enough)
• Lilly press release, Sep 29, 2026 (indirect comparison, company-reported)
• Joint advisory: Nutritional Priorities to Support GLP-1 Therapy for Obesity, May 2025 (protein and strength training to preserve lean mass)