The scale is finally moving. Your clothes fit differently, the constant negotiation with food has quieted, and a number you'd been chasing for years suddenly feels within reach. Then someone raises a question you didn't expect: is some of what you're losing muscle?
It's a fair question, and the honest answer is that some of it can be. That isn't a sign the medication is failing you. Weight lost by almost any method comes as a mix of fat and lean tissue, and the way you eat and move while you lose changes that mix quite a bit. Understanding that early is what lets you shape it.
So let's talk about what actually happens to muscle on a GLP-1, why it matters, and the two things with the best evidence behind them for holding onto the strength you have.
Some of the weight you lose is muscle, and that's normal
Here's the part a quick search rarely explains cleanly. In the BELIEVE trial, a 72-week study of 507 adults with obesity published in Nature Medicine, people taking semaglutide on its own lost about 15.7 percent of their body weight. Of that loss, roughly 24 percent was lean mass rather than fat. In plain terms, about a quarter of what came off was not fat tissue.
That figure tends to alarm people at first, so it's worth putting in context. Losing some lean mass alongside fat is not unique to these medications. It happens with dieting, with surgery, with almost any meaningful weight loss. The body simplifies down, and muscle is part of what it trims. What the research keeps showing is that this fraction isn't fixed. It responds to what you do while the weight is coming off, which is exactly where you have leverage.
Why holding onto muscle is worth the effort
Muscle does more than fill out a sleeve. It's metabolically active tissue, meaning it burns energy even at rest, so keeping it helps steady the metabolism you're trying to reset. It plays a role in how your body handles blood sugar. And over the longer arc of life, muscle is what keeps you steady on your feet, carrying groceries, getting up from the floor, staying independent as the years add up.
The four-society advisory we'll get to below names muscle and bone loss directly as a challenge to manage during GLP-1 therapy, not an afterthought. That framing matters. The goal of losing weight was never to become a smaller, frailer version of yourself. It was to feel better and move through your life more easily. Protecting muscle is how the results you want stay durable instead of borrowed.
The two levers with the most evidence: protein and strength
In 2025, four organizations, the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and The Obesity Society, published a joint advisory on nutrition during GLP-1 therapy. Among its eight priorities, one speaks straight to this concern: adequate protein intake paired with strength training to preserve lean mass.
Neither of those is exotic, which is rather the point. Because these medications quiet appetite so effectively, it's easy to eat too little of everything, protein included, without noticing. Being deliberate about protein across your meals, and adding resistance work, whether that's weights, bands, or bodyweight movement, gives your body a reason to keep the muscle it might otherwise let go. The advisory stops short of a single universal protein number, and that's honest: the right target depends on your size, your labs, and your history, which is a conversation to have with a physician rather than a figure to copy from a chart.
What the newest research is testing
The muscle question is an active frontier, not a settled one. The same BELIEVE trial also tested pairing semaglutide with an investigational antibody called bimagrumab that targets muscle directly. In that combination arm, participants lost about 22 percent of their body weight, and only around 8 percent of that loss was lean mass, meaning far more of it was fat.
That's a striking contrast to the roughly 24 percent lean fraction with semaglutide alone. It's also important to read carefully: the trial describes bimagrumab as investigational, and it is not FDA approved, so this points to where the science is heading rather than to something available at a pharmacy today. The practical takeaway for right now hasn't changed. The tools you can actually use, protein and resistance training alongside supervised medication, are the ones already backed by the current advisory. If you're weighing the newer oral GLP-1 options as part of this, the same principle holds regardless of which molecule you take.
What this means for you, here in Lubbock
Picture a hypothetical patient, a high school teacher in Lubbock who started a GLP-1 last spring. The weight is down, the knees feel better on the stairs, and she wants to make sure that when summer ends she's stronger, not just lighter. What she needs isn't only a prescription. It's a plan: protein she'll actually eat given a quieter appetite, a couple of strength sessions that fit a real week, and someone checking her progress over time rather than at a single visit.
That's the piece we care about most. When Dr. Sima Shahbandar works with someone on weight, the medication is one part of a fuller picture that folds in nutrition, movement, and follow-up, the kind of ongoing attention that longer appointments make possible. The goal is that the version of you at the end of this is one you'd recognize and feel good in.
Talk it through with us
If you're on a GLP-1 or thinking about starting one and you want the muscle side handled thoughtfully, not left to chance, that's a conversation we're glad to have. Our approach to weight loss is built around supervision and a plan that fits your life, not a one-size protocol, part of our broader wellness care. Reach us through our contact page or call (806) 778-4395, and we'll walk you through what supported, muscle-aware weight loss can look like for you.
Sources
- Weight loss and lean mass fractions in the BELIEVE phase 2 trial (507 adults, 72 weeks): Bimagrumab plus semaglutide for the treatment of obesity, Nature Medicine, 2026
- Protein and strength training to preserve lean mass, and the eight nutritional priorities: Nutritional Priorities to Support GLP-1 Therapy for Obesity, joint advisory of ACLM, ASN, OMA, and The Obesity Society, 2025
This article is for general educational purposes and is not medical advice, diagnosis, or treatment, and it does not create a physician-patient relationship. Individual results vary, and no outcome is guaranteed. Treatment decisions should be made with a qualified physician who knows your full medical history. Omri Med is a private-pay concierge practice; membership is limited and does not replace health insurance.