How Much Muscle Will You Lose from Taking Ozempic? Key Considerations Before You Start

It has become increasingly commonplace to hear people in your social circle opting to take GLP-1 agonists, most popularly Ozempic, for weight loss. Many of these individuals will oftentimes have no history of Type 2 Diabetes, the intended patient population for these drugs. While these medications have gained immense popularity due to their effectiveness amongst those struggling with obesity, it is less common to discuss the undesired consequences of losing body weight too fast.

It is important to know what these drugs even are. The class of weight-loss drugs known as GLP-1 agonists include Ozempic, Wegovy, and Mounjaro. GLP stands for “glucagon-like peptide”, and glucagon is a hormone that is naturally produced by our pancreas to raise blood sugar levels in our body. An “agonist” is a fancy way of saying that a compound activates a specific biological response. So these drugs work by convincing the pancreas to make insulin and also slows stomach emptying, which helps you regulate appetite.

A major reason these drugs work is that they affect our food drive - the desire to want to eat. By reducing the urge to consume food, we artificially create a caloric deficit. It's this same caloric deficit you hear us physical therapists harp on about when talking about natural weight loss. You simply consume less calories in your day than your body burns off - easier said than done when you are constantly hungry because of it. 

So when individuals use GLP-1 agonists like Ozempic, they experience significant weight loss due to reduced appetite and caloric intake. While this may seem beneficial, the loss of weight is not always accompanied by a corresponding preservation of muscle mass. When weight loss occurs too rapidly, the body may break down muscle tissue along with fat, leading to a decrease in overall muscle mass. If the muscle loss is significant enough, we call this Sarcopenia. Sarcopenia is often associated with moving less as we age, but it can also be exacerbated by rapid weight loss and inadequate protein intake.

One of the key factors in preventing sarcopenia is ensuring adequate protein intake and engaging in regular resistance training. Shocker coming from a physical therapist, I know.

How much protein? Approximately one gram of protein per one pound of body weight. So if I was 150lbs, I would aim for at least 150 grams of protein per day. If you are not sure what that realistically looks like, I have attached a visual chart: 

Practically, aim to include at least some quality protein source with every meal. If you are really unsure if that amount is enough, supplement your normal meal schedule with a protein shake which typically contains 20 - 40 grams of protein per serving just by themselves. With enough protein intake, you give your body the building blocks to maintain and improve muscle mass regardless of the total number of calories you consume in a day. 

A regular resistance training routine is the final piece of the puzzle. Resistance exercise is what turns the protein you eat, specifically the nitrogen molecules in that protein, into muscle tissue in the body region that exercise was intended to target. At the very least, having a positive nitrogen balance in your body from enough protein intake will prevent your endocrine system from stealing muscle that you have already built.

Our job as physical therapists is to guide you on what strength movements would benefit you the most personally, so reach out to your therapist if you are unsure what exercises are best. 

Disclaimer: This information is meant for educational purposes and does not supersede or replace direct medical advice from your MD or Certified Dietitian. 

References:

1. Bergmann NC, Davies MJ, Lingvay I, Knop FK. Semaglutide for the treatment of overweight and obesity: A review. Diabetes Obes Metab. 2023;25(1):18‐35.
2. Bikou, A., Dermiki-Gkana, F., Penteris, M., Constantinides, T. K., & Kontogiorgis, C. (2024). A systematic review of the effect of semaglutide on lean mass: insights from clinical trials. Expert opinion on pharmacotherapy, 25(5), 611–619.
3. Mechanick JI, Butsch WS, Christensen SM, et al. Strategies for minimizing muscle loss during use of incretin-mimetic drugs for treatment of obesity. Obesity Reviews. 2025;26(1):e13841.