Can GLP-1 Medications Cause Muscle Loss?
What You Need to Know

GLP-1 receptor agonists, like Ozempic, Wegovy, Monjauro, Zepbound, semaglutide, and tirzepatide, are commonly used to treat type 2 diabetes (T2D) and support weight loss. These medications help the body manage blood sugar, reduce hunger, and promote fat loss. However, new concerns have emerged about their potential role in muscle loss, also known as sarcopenia—the loss of muscle mass and strength as we age.

1. Rapid Weight Loss and Muscle Reduction

• GLP-1 medications promote significant weight loss, but not all of it comes from fat—some of it comes from muscle.
• Studies show that up to 40% of weight lost on GLP-1 therapy may be lean muscle mass.
• Losing muscle too quickly, especially without exercise or enough protein, can weaken the body and slow metabolism.

2. Lower Appetite = Less Protein Intake

• GLP-1 medications suppress hunger, making it easier to eat less.
• However, this often means people don’t eat enough protein, which is crucial for maintaining muscle.
• A lack of protein over time can lead to muscle breakdown and weakness.

3. Changes in Muscle Metabolism

• These medications affect how insulin works in muscles, which may reduce muscle growth and repair.
• Older adults and people with obesity or diabetes already struggle to build muscle, and GLP-1s may make it harder.

4. Increased Fat Burning Over Muscle Preservation

• GLP-1 medications push the body to burn fat for energy, but if protein and exercise levels are too low, muscle can also be broken down.
• Without enough food and exercise, the body might use muscle for fuel, leading to weakness over time.

STEP Trials (Semaglutide and Weight Loss)

• Studies found that people using semaglutide (Wegovy, Ozempic) lost significant amounts of lean muscle along with fat.
• One trial showed that nearly 40% of weight loss was from muscle, which raised concerns about muscle health.

Diabetes and Muscle Function

• Some research shows that GLP-1 medications improve blood sugar control in muscle.
• Other studies suggest long-term users may experience reduced muscle mass.

Older Adults Are at Higher Risk

• Sarcopenia (muscle loss) is already a risk for older adults, and using GLP-1 medications without proper diet and exercise could make it worse.

1. Strength Training and Resistance Exercise

• Lifting weights, bodyweight exercises, and functional training can help preserve and build muscle.
• Aim for at least 2–3 resistance training sessions per week.

2. Increase Protein Intake

• Eat more protein to help maintain muscle mass.
• Recommended: 1.2–1.6 grams of protein per kg of body weight daily.
• Best sources: lean meats, fish, eggs, dairy, beans, and nuts.

3. Consider Creatine Supplements

• Creatine monohydrate is proven to help maintain and build muscle during weight loss.

4. Monitor Your Lean Mass

• Track changes in body composition to ensure you are losing mostly fat, not muscle.
• Some doctors may adjust GLP-1 medication dosage based on muscle changes.

5. Adjust Dosing & Lifestyle for Muscle Preservation

• Doctors may lower doses or recommend cycles of GLP-1 medications to balance weight loss and muscle preservation.
• Regular exercise, a high-protein diet, and proper monitoring can help minimize muscle loss.

GLP-1 medications are highly effective for weight loss and blood sugar control, but they may also contribute to muscle loss if not used carefully. To protect your muscle strength and metabolism, focus on resistance training, eating enough protein, and monitoring your lean mass. If you’re using GLP-1 therapy, talk to your doctor about ways to preserve muscle while losing weight. More research is needed to fully understand how these medications impact muscle health, but taking proactive steps can help you stay strong and healthy.