{"id":630764,"date":"2025-01-02T09:30:10","date_gmt":"2025-01-02T14:30:10","guid":{"rendered":"https:\/\/www.singlecare.com\/blog\/?p=630764"},"modified":"2025-05-20T15:06:35","modified_gmt":"2025-05-20T19:06:35","slug":"glp-1-muscle-loss","status":"publish","type":"post","link":"https:\/\/www.singlecare.com\/blog\/glp-1-muscle-loss\/","title":{"rendered":"Do GLP-1s cause muscle loss?"},"content":{"rendered":"

Glucagon-like peptide-1 receptor agonists (GLP-1s) are drugs that act like the GLP-1 hormone that the human body should release naturally in the gastrointestinal tract after eating. GLP-1 performs many functions in the body, including triggering the release of insulin from the pancreas, improving insulin resistance, slowing down the emptying of the stomach, and increasing the feeling of satiety. Hence, your body knows it\u2019s not hungry anymore. GLP-1 drugs are FDA approved for the management of <\/span>Type 2 diabetes<\/span><\/a> (<\/span>Ozempic<\/span><\/a>\u00a0 and <\/span>Mounjaro<\/span><\/a>), obesity (<\/span>Wegovy<\/span><\/a> and <\/span>Zepbound<\/span><\/a>). However, sometimes Ozempic or Mounjaro are prescribed off-label for weight loss.\u00a0<\/span><\/p>\n

People using GLP-1 inhibitors may experience significant muscle loss. Still, it is thought to be attributed to the very rapid weight loss GLP-1 drugs can cause rather than a direct result of the drugs themselves.<\/span><\/p>\n

What happens to muscles when you lose weight?<\/span><\/h2>\n

\u201cDuring traditional weight loss, the body tends to break down both fat and muscle tissue as an energy conservation mechanism,\u201d explains Michael Baumholtz, MD, a plastic surgeon at San Antonio Gynecomastia Center who frequently treats patients for weight loss with GLP-1s before their surgical procedures. \u201cRapid weight loss (which is more characteristic of GLP-1s) can accelerate this process if not properly managed.\u201d<\/span><\/p>\n

A systematic review and meta-analysis published in <\/span>The American Journal of Clinical Nutrition<\/span><\/i><\/a> of 41 trials involving 15,135 participants showed that individuals taking GLP-1s showed a significant reduction in metrics, including body weight, body mass index (BMI), and waist circumference. However, the weight loss experienced with GLP-1s has been shown to be significant, and in some cases, may occur at a rate higher than the one to two pounds a week recommended by the <\/span>Centers for Disease Control and Prevention (CDC)<\/span><\/a>.<\/span><\/p>\n

\u201cRapid weight loss often results in a higher percentage of muscle mass loss compared to slower, more gradual weight loss,\u201d cautions <\/span>Eric Smith, MD<\/span><\/a>, bariatric surgeon and medical director at POP Recovery System. \u201cThis loss is especially concerning as muscle plays a key role in maintaining basal metabolic rate (BMR)\u2014the calories your body burns at rest. A lower BMR due to muscle loss makes it harder to maintain weight loss and increases the likelihood of regaining weight.\u201d<\/span><\/p>\n

Rapid weight loss can be a result of using GLP-1s or from other weight loss interventions, such as bariatric surgery, calorie restriction, or excess energy expenditure. If you are experiencing rapid weight loss as a result of GLP-1s or a surgical procedure, work closely with your healthcare provider to learn how to retain lean body mass and avoid sarcopenic obesity\u2014excess fat tissue accompanied by muscle loss\u2014on your weight loss journey.<\/span><\/p>\n

Do GLP-1s cause muscle loss?<\/span><\/h2>\n

While GLP-1 agonist drugs themselves have not been shown to cause muscle loss, as experts note, rapid weight loss characteristic of taking GLP-1s can cause muscle loss and affect body composition. \u201cStudies suggest that up to 40% of weight lost while using GLP-1 receptor agonists, such as Ozempic or Wegovy, can come from muscle mass,\u201d says Dr. Smith. \u201cThis is a significant concern because muscle mass is essential for maintaining a healthy metabolic rate and long-term weight management. Losing muscle during weight loss can predispose individuals to weight regain.\u201d<\/span><\/p>\n

A study in <\/span>The Lancet<\/span><\/i><\/a> finds that muscle loss when taking GLP-1s can account for as much as 25% to 39% of the total weight lost over 36\u201372 weeks.<\/span><\/p>\n

A review of clinical trials published in <\/span>Diabetes, Obesity, and Metabolism<\/span><\/i><\/a> showed a range of findings. One trial reported semaglutide (the active ingredient in Ozempic and Wegovy) was associated with a loss of fat-free mass (FFM) of up to 45.2% and liraglutide (the active ingredient in Victoza and Saxenda) with a loss of up to 60%, while tirzepatide (the active ingredient in Mounjaro and Zepbound) showed only 25.7%. However, other studies show a similar loss of lean muscle mass across both drugs and a placebo (inactive medicine) group.<\/span><\/p>\n

\u201cPreliminary data suggest that different GLP-1 agonist medications may vary slightly in their impact on muscle loss,\u201d Dr. Smith explains. \u201cFor example, some evidence indicates that <\/span>Ozempic<\/span><\/a> (manufactured by Novo Nordisk) may lead to slightly more muscle loss compared to <\/span>Zepbound<\/span><\/a> (manufactured by Eli Lilly). However, research is still limited, and further studies are needed to confirm these differences and understand the long-term effects of these medications.\u201d<\/span><\/p>\n

Dr. Baumholtz<\/span><\/a> has not noted any difference in muscle loss between the different GLP-1 agonist drugs. \u201cFrom my experience, I have not seen material differences between GLP-1s in terms of muscle loss potential, certainly not enough difference to recommend one versus the other. What matters most is the individual patient’s overall weight loss approach, including how they\u2019re combining the medications with lifestyle changes, nutrition, and exercise.\u201d<\/span><\/p>\n

A <\/span>recent animal study<\/span><\/a> concluded that combining GLP-1 treatment with myostatin inhibitors, a potential <\/span>treatment<\/span><\/a> for muscle wasting disorders may help preserve lean muscle mass during weight loss. However, these drugs aren\u2019t available yet, and further research in humans is needed.<\/span><\/p>\n

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