Ozempic and Muscle Loss: How to Keep Your Strength While Losing Weight

If you’ve started Ozempic (semaglutide) for weight loss, you may have seen headlines warning about muscle loss on Ozempic. This has become one of the most common concerns people have when beginning treatment — and a very valid one.

So the natural question is: Does Ozempic cause muscle loss?

The short answer is yes, but the real answer is more complicated than that. What’s important to know is that muscle loss can occur with any significant weight loss and it is more likely to happen with large amounts of rapid weight loss. When people take too high of a dose and aren’t eating enough nutrients and protein to fuel their body, Ozempic use can contribute to muscle loss. But it’s important to know that the medication itself is not directly damaging muscle tissue and some animal studies have demonstrated some muscle-protective effects (1).

The real issue is that any time you lose weight quickly, your body typically loses both fat and muscle. The good news is that muscle loss is largely preventable with the right nutrition and exercise strategy. With a few simple adjustments, most people can protect their muscle mass while losing body fat.

Clinical trials have measured body composition changes during treatment with semaglutide.

In the STEP-1 trial, participants lost an average of about 13.6 kg (30 pounds) of body weight during treatment with Ozempic (3). Body composition was not a primary endpoint of the original STEP-1 trial, but a DXA substudy in a subset of participants later evaluated changes in lean mass during treatment. Body composition analysis showed that approximately 20–40% of the weight lost came from lean mass, which includes muscle tissue (4).

This percentage may sound alarming, but it is actually very similar to what we see with other forms of weight loss, including traditional calorie-restricted diets and bariatric surgery (5). Researchers have consistently found that some lean mass loss occurs whenever significant weight loss takes place.

The important takeaway is that the majority of weight lost is still body fat, and the amount of muscle loss can often be minimized with the right approach.

Maintaining muscle during weight loss comes down to two key factors: protein intake and muscle stimulus. When both of these are present, your body is much more likely to preserve muscle mass during weight loss.

1. Eat enough protein

Because Ozempic reduces appetite, many people unintentionally eat far less protein than their body needs. Your muscles act as your body’s pantry storing nutrients for later use. When protein intake is too low, the body may begin breaking down muscle tissue to access the amino acids it needs for essential functions like your brain and your heart.

A reasonable protein target during weight loss is approximately 0.7–1.0 grams of protein per pound of lean body mass (6). This level of intake helps support muscle preservation, metabolic health, feeling full and satisfied, and energy levels.

A simple way to reach this goal is to aim for 30–40 grams of protein at each meal. Incorporating simple whole foods like chicken, fish, tofu, Greek yogurt, or cottage cheese will get you there in no time. When appetite is low, protein shakes or smoothies can be helpful. For a deeper dive on protein targets, see our guide on GLP-1 and muscle loss.

2. Strength training

The second key signal muscles need is mechanical stimulus. Strength training tells the body that muscle tissue is still needed. Without this signal, the body may reduce muscle mass during weight loss. The good news is that you do not need intense workouts to see benefits. Even 20–30 minutes of resistance training two to three times per week can significantly improve muscle preservation.

This could include weight training, resistance bands, bodyweight exercises, or supervised gym programs. The goal is simply to use the muscles regularly so the body keeps them. The key is finding things that fit your fitness level and you enjoy. When you enjoy the exercise, you’re helping your body become stronger and you’re more likely to do it consistently.

If you are new to strength training or you are dealing with an injury, it may be beneficial to work with a certified trainer or physical therapist. A trainer is a qualified professional who has passed a recognized, accredited exam (such as NASM, ACE, ACSM, or NSCA) and will ensure you are doing exercises correctly at an appropriate weight load to avoid injury. If you already have an injury you are working through or limited mobility, working with a physical therapist can help get you moving safely for your body. At the end of the day, both options can help you reach your movement goals.

Tracking your progress on your journey is a key component to success. While a simple weight scale is a great start, it is not the whole picture of what is going on with your overall body composition.

Body composition analysis by a bioimpedance scale can measure how much muscle vs fat vs water make up your body. It is important to know your baseline measurements and monitor, at least monthly, to ensure that you are losing body fat and maintaining muscle on your weight loss journey. You can often find one of these scales at your local gym or doctor’s office.

Another way to track your progress is through pictures and measurements. Often we don’t see the small changes that are occurring because we look at ourselves on a daily basis. If you are feeling stuck it can be a great way to see and feel the differences that are happening. Non-scale victories, like fitting into your favorite pair of jeans again, can feel even more motivating and empowering!

Absolutely! Yes, muscle loss during weight loss does not have to be permanent.

While our bodies can usually metabolically focus on one change at a time, like building muscle or losing fat, muscle tissue is very adaptable and can be rebuilt when the body receives the right signals. This is why bodybuilders go through different phases in their training. They will often cut phase, then muscle building phase, then trim phase again before a competition.

After you’ve reached your weight loss goal with Ozempic and your weight stabilizes (cut phase), you can begin to build muscle by increasing protein intake, dialing in resistance training and overall calorie intake (build phase). This can allow the body to rebuild lost muscle mass over time. It is normal to gain a little body fat back with the muscle gain, so don’t lose heart. You are doing great things for your body with building muscle and you can trim down again on the back end of the build phase.

In fact, many people find that after reaching their weight goal, they are able to focus on strength training and muscle building more effectively. The key is to maintain healthy nutrition habits even after the medication phase of treatment.

Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) are both medications used to treat obesity and metabolic disease. They work through slightly different mechanisms, but both promote weight loss by reducing appetite, improving blood sugar regulation and slowing stomach emptying.

Clinical trials for both medications show similar patterns of body composition change. In the SURMOUNT trials studying tirzepatide, researchers observed that lean mass also decreased during weight loss, although the majority of weight lost remained body fat (7).

Current evidence suggests that muscle loss during treatment is primarily related to weight loss itself, not necessarily the specific medication being used. The same strategies apply regardless of which drug is prescribed: ensure adequate protein intake, incorporate regular strength training, and gradual weight loss when possible. For tirzepatide-specific guidance, see our article on Mounjaro diet plans.

1. Yang, Rong-Sen, et al. Glucagon-like peptide-1 receptor (GLP-1R) agonists prevent tributyltin-induced muscle atrophy/wasting via restoring GLP-1R signaling in vitro and in mice. Ecotoxicology and Environmental Safety. 2026;309. https://doi.org/10.1016/j.ecoenv.2025.119523
2. Hunter GR, Plaisance EP, Fisher G. Weight loss and bone mineral density. Curr Opin Endocrinol Diabetes Obes. 2014;21(5):358-62. https://doi.org/10.1097/MED.0000000000000087
3. Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine. 2021;384(11):989-1002. https://doi.org/10.1056/NEJMoa2032183
4. Wilding JPH, Batterham RL, Calanna S, et al. Impact of Semaglutide on Body Composition in Adults With Overweight or Obesity: Exploratory Analysis of the STEP 1 Study. J Endocr Soc. 2021;5(Suppl 1):A16–17. https://doi.org/10.1210/jendso/bvab048.030
5. Nuijten MAH, Eijsvogels TMH, Monpellier VM, et al. The magnitude and progress of lean body mass, fat-free mass, and skeletal muscle mass loss following bariatric surgery: A systematic review and meta-analysis. Obesity Reviews. 2022;23(1):e13370. https://doi.org/10.1111/obr.13370
6. Mozaffarian D, Agarwal M, Aggarwal M, et al. Nutritional priorities to support GLP-1 therapy for obesity: A joint advisory. American Journal of Clinical Nutrition. 2025. https://doi.org/10.1016/j.ajcnut.2025.04.023
7. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine. 2022;387:205-216. https://doi.org/10.1056/NEJMoa2206038