Will you lose muscle on Ozempic or Mounjaro?

GLP-1 medications like Ozempic, Wegovy and Mounjaro are very effective for weight loss. The catch is that not all of the weight you lose is fat. A meaningful share of it can be lean mass, which mostly means muscle.

How much of the loss is muscle?

Across studies of rapid weight loss, lean mass commonly makes up 25 to 40 percent of the total lost. Two things make this worse on a GLP-1 medication:

• Appetite drops sharply, so protein intake often falls below what your body needs.
• Many people move and train less while losing weight, which removes the signal that tells your body to keep muscle.

Lose muscle and your metabolism slows, you feel weaker, and weight is easier to regain later.

How to keep your muscle

You cannot fully stop lean-mass loss during a calorie deficit, but you can blunt it. Two levers do most of the work:

1. Eat enough protein. A common target is around 1.8 grams per kilogram of bodyweight per day.
2. Do resistance training. Two to three sessions a week gives your body a reason to hold on to muscle.

See where your loss is going

Log your weight over a few weeks and BMI Kit estimates your lean mass and FFMI, then flags when too much of your loss is muscle.

Open the muscle tracker, or check your FFMI and body fat to set a baseline first.

This guide is general wellness information, not medical advice. For personal guidance, talk to a nutrition coach or your healthcare provider.