Weight Loss

What to know about Semaglutide rapid weight loss concerns, like muscle loss and bone health

Learn how prescription weight loss medications affect muscle mass and bone density. Plus, ways food and nutrition habits can help you stay strong and stable.
Strong young woman performs a barbell squat in a gym, she looks confident and focused.

Key Points:

  1. Losing weight can increase the risk of muscle and bone density loss, whether a person takes compounded Semaglutide, diets or has weight-loss surgery.
  2. Muscle mass and bone density changes make people more susceptible to falling, breaking bones and losing their independence—especially as they age.
  3. Eating balanced, protein-rich meals and engaging in enjoyable physical activities (especially weight training or resistance exercises) is the safest way to encourage healthy weight management while on prescription weight loss medications.

Prescription weight loss medications can be helpful for people who struggle with their metabolism, medical conditions or other concerns. But the metric used to determine who qualifies for this treatment—the body mass index, or BMI—doesn’t provide a complete picture of a person’s health. It doesn't account for bone density, muscle mass, blood pressure or other factors that mark health status or a risk of developing a serious health condition.

Losing significant amounts of weight doesn't automatically make someone healthier, either!

Are you healthier if you shed pounds but don’t also shed joint pain, sleep issues, brain fog, low energy levels or heart disease risk?

Here, we explain how prescription weight loss medications (and their compounded versions) affect muscle and bone health. Plus, how a few intentional additions to your movement and eating habits can help you stay strong while you shed the things no longer serving you.

What is Semaglutide?

Semaglutide is a safe and effective prescription weight-loss treatment for adults who meet certain conditions. It’s the same active ingredient in brand-name medications including Ozempic® and Wegovy®.

These medicines are called GLP-1 agonists because they mimic the ​​glucagon-like peptide-1 hormone naturally made in the body to slow digestion and control appetite.

While Semaglutide can help some people eat less and lose weight, there are concerns about how it affects lean muscle loss and bone density. There isn't much long-term research on the specific impact of Semaglutide on these areas. But studies on rapid weight loss and general weight management guidance confirm that exercise is essential for patients using the medication.

Here’s what the research suggests.

How does Semaglutide cause muscle loss?

Weight loss happens when we expend more calories in energy than we eat through food. If we drastically reduce our calorie intake and don’t exercise, much of the weight we lose may come from both fat and muscle loss—because our body is looking for energy to burn from the nearest source!

Semaglutide causes rapid weight loss. So studies suggest that 20% to 50% of overall loss for patients who take it comes from losing lean body mass. Lean body mass includes muscle, fluid and bone mass—all but fat!

This loss can cause a few issues:

If we lose weight but then stop dieting or taking Semaglutide, we may regain weight made up of only fat. So we’ll be in worse physical shape than we were before.

That’s because our muscles help us sit, stand, move, maintain balance and perform everyday tasks. When we lose muscle mass, we lose strength and stability. This is especially true among older adults, who face increased risk of falls, broken bones and hospital stays when they lose the muscles they need to stay stable.

So lowering body weight might help us reach health goals like lowering blood pressure, easing joint pain or improving heart health. But unintentional muscle mass loss might become an issue at the same time.

That’s why early research on Semaglutide muscle loss suggests exercising to maintain lean muscle while losing weight is the best way to encourage long-lasting weight management.

How does Semaglutide impact bone health?

More studies are needed in this area, too! But researchers are already seeing that Semaglutide may affect bone health.

Bones can become less dense as we lose weight for any reason—even moderate decreases in weight can cause bone loss. But it’s especially true when we lose a significant amount of weight over a short period.

This may be because when we reduce calorie consumption, we may take in less calcium and Vitamin D. Also, Semaglutide slows the process by which food empties our stomach. So it may affect how our body absorbs calcium (and other nutrients). Hormonal shifts may play a part for women, too.

Whatever the reason, lower bone density raises the risk of fracture or breakage—especially if we have an existing bone condition or have fractured a bone in the past.

If you’re concerned about bone health, discuss your concerns with your healthcare provider before using Semaglutide. They may suggest specific tests or prescribe calcium or Vitamin D supplementation.

How can I prevent muscle and bone density loss while taking Semaglutide?

As research continues into Semaglutide’s ties to muscle mass and bone density, most health experts agree that engaging in activities that improve muscle, bone and cardiovascular health is important if you want safe, lasting change while using a prescription weight loss medication.

Talk to your provider before any diet or exercise regimen. Or get even more personalized instruction from a licensed personal trainer, dietitian or nutrition coach.

Otherwise, these tips can get you started:

  • Get regular exercise while using Semaglutide. Aim for 150-300 weekly minutes of moderate-intense aerobic activity or 75-150 minutes of vigorous-intense aerobic activity.
  • Move your body in ways that you love! To get those minutes in, try a combination of dancing, martial arts, running, biking, walking, cycling, hiking or swimming.
  • Prioritize resistance or weight training at least twice a week. Lifting small weights, using elastic bands, or trying push-ups, planks, or other bodyweight exercises can build muscle and improve bone density over time.
  • Eat .5-.8 grams of protein per pound of your body weight every day from lean, quality protein sources.
  • Eat nutrient-dense complex carbohydrates to encourage digestion and optimum health.
  • Stay hydrated with water and other non-alcoholic beverages—this supports digestion, which will help give your muscles and bones necessary nutrients!
  • Before trying supplementation, ask your provider if calcium or Vitamin D supplements might benefit your muscle mass and bone density.

Can I get Semaglutide online?

Prescription weight loss drugs like Semaglutide can only be prescribed by a licensed provider alongside exercise and diet modification. Fortunately, Dr. B offers Semgaglutide from vetted compounding pharmacies tested for safety and effectiveness via Shed It with Dr. B!

Our holistic weight loss program combines prescription treatment with streamlined support tools and motivating partner programs—all for an inclusive and affordable monthly fee. Start an online consultation to find out if you qualify for treatment today!

*Ozempic® and Wegovy® are registered trademarks of their respective owners. Our use of these names is for informational purposes only and does not imply any affiliation, endorsement or approval by the trademark holders.

Sources:

Alabduljabbar, K., et al. (2022). The impact once-weekly Semaglutide 2.4 mg will have on clinical practice: A focus on the STEP trials. Nutrients.

Blum, D. (2023). The risks of taking drugs like Ozempic when you’re over 65. The New York Times.

Cava, E., et al. (2017). Preserving healthy muscle during weight loss. Advances in Nutrition.

Christoffersen, B. O., et al. (2022). Beyond appetite regulation: Targeting energy expenditure, fat oxidation, and lean mass preservation for sustainable weight loss. Obesity.

Hansen, M. S. (2024). Once-weekly Semaglutide versus placebo in adults with increased fracture risk: a randomised, double-blinded, two-centre, phase 2 trial. The Lancet.

Mayo Clinic. (2023). Strength training: Get stronger, leaner, healthier.

McCarthy, D., et al. (2021). Weight loss strategies and the risk of skeletal muscle mass loss. Nutrients.

Sargeant, J.A. (2019). A review of the effects of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors on lean body mass in humans. Endocrinology and Metabolism.

US Department of Health and Human Services. (2018). Physical activity guidelines for Americans, 2nd edition.

Sign up for the free Dr. B newsletter for a weekly report on the latest in healthcare + research-based advice for staying healthy and mentally well.

Related articles