GLP-1s and Muscle Loss in Menopause: What to Eat to Protect It
By Lisa Collins | Fact Checked | Sources
Key Takeaways
- The scary number you have seen online is real, but it is being quoted wrong almost everywhere. Roughly 25 to 40 percent of the weight you lose on a GLP-1 is lean mass. That is a share of what comes off, not a share of the muscle you have.
- Here is the part almost nobody is publishing: in the SURMOUNT-1 body composition data, the placebo group lost lean mass in nearly the same proportion as the medication group. 25 percent versus 26 percent. Losing weight means losing some lean mass, whether or not a medication is involved.
- A small March 2026 study in Cell Reports Medicine, 10 people over 12 weeks, found that while thigh muscle size went down, handgrip and knee extension strength did not. It is too small to settle anything on its own, but it points at something the headlines keep missing: size and strength are not the same measurement.
- Protein is the lever with the most evidence behind it. The 2025 to 2030 Dietary Guidelines for Americans put the range for adults at 1.2 to 1.6 grams per kilogram of body weight per day. Spread it across the day rather than stacking it at dinner.
- Resistance training is not optional here. Guidelines point to strength training at least three times a week. Food protects muscle. Lifting is what tells your body to keep it.
If you have spent five minutes in a menopause group lately, you have seen the posts. Someone starts a GLP-1, someone else replies within the hour to warn her she is going to lose a quarter of her muscle. Then forty women pile in, half terrified, half defensive, and nobody actually links the study.
I have watched this play out over and over. The comment that gets screenshotted the most goes something like: "You will lose 25 to 40 percent of your muscle mass on Ozempic." I understand why that spreads. It is frightening and it sounds specific. It is also not what the research says.
So let us do the Morphus thing. Instead of repeating the fear or dismissing it, we are going to look at where that number actually comes from, what it means, what it does not mean, and exactly what to put on your plate if you are taking one of these medications in perimenopause or menopause. There is also one finding buried in the data that reframes this entire conversation, and I want to make sure you have it.
The number everyone is scared of, and what it actually says
The figure is real. It comes from a fairly consistent body of research, and Mayo Clinic's GLP-1 nutrition guide states it plainly: approximately 25 to 40 percent of weight loss during GLP-1 therapy may come from lean mass.
Read that sentence one more time, slowly. Twenty-five to forty percent of the weight you lose. Not 25 to 40 percent of the muscle on your body.
The difference is enormous. If you lose 30 pounds and roughly a third of that is lean mass, that is about 10 pounds of lean tissue, and lean mass includes water, glycogen, and connective tissue, not only muscle fiber. That is a real thing worth managing. It is not the same as losing a third of your body's muscle, which would be a medical emergency.
Where do the specific numbers come from? Two of the big trials sit at either end of the range. In SURMOUNT-1, the tirzepatide trial, about a quarter of the weight lost was lean mass. In STEP-1, the semaglutide 2.4 mg trial, it was closer to 39 percent. A meta-analysis published in Obesity, pooling nine randomized controlled trials, landed at roughly 31 percent. So the 25 to 40 range is fair. It is the denominator that keeps getting mangled as it travels through Instagram captions and podcast intros.
I want to be honest that our own content has not been immune to this. More on that further down.
The part almost nobody is telling you
Now here is the finding I have not seen a single mainstream menopause account cover, and it changes how you should think about all of this.
In 2025, Look and colleagues published the body composition substudy from SURMOUNT-1 in Diabetes, Obesity and Metabolism. They used DXA scans to break down exactly what participants lost. The tirzepatide group, 124 people, lost weight that was 74 percent fat and 26 percent lean mass.
The placebo group, 36 people, lost weight that was 75 percent fat and 25 percent lean mass.
Twenty-five versus twenty-six. Essentially identical. And since most of us reading this are women: among the women in the study, 75 percent of the weight lost was fat on tirzepatide and 75 percent on placebo.
One thing you should know about this study: it was funded by Eli Lilly, the company that makes tirzepatide. What makes the result hard to spin is that the comparison group was built into the same trial, measured the same way.
Sit with that for a second. The people who were not on the drug lost lean mass in the same proportion as the people who were. Which tells us something important: losing lean mass is what losing weight is. It is not a special toxic side effect the medication inflicts on you. It is what happens to a human body when it gets smaller, by any method. Mayo Clinic's guide says the same thing, noting this pattern is not unique to GLP-1s and shows up with any significant weight loss.
A March 2026 paper adds another piece, with a big caveat attached. Langer and colleagues, writing in Cell Reports Medicine, studied mice and a small group of people, and titled their paper about as directly as researchers ever do: weight loss with GLP-1 medicines does not result in a disproportionate loss of muscle mass or function. In their human data, about 70 percent of weight lost was fat. And they measured strength, not just size. Thigh muscle size went down. Maximum voluntary contraction during knee extension did not change. Handgrip strength did not change.
Now the caveat. The human part of that study was 10 adults with type 2 diabetes, on semaglutide for 12 weeks, and the authors themselves describe it as a proof of concept without the power to draw firm conclusions. So treat it as a promising signal, not a verdict.
Even so, that distinction between muscle size and muscle function is the one I most want you to carry out of this article. A smaller muscle that still does its job is a very different situation from a weak one. Most of the online panic treats a DXA number as if it were a measure of how strong you are. It is not.
I do want to flag the honest limits of SURMOUNT-1 too. The placebo group was small, only 36 people, and they lost far less total weight overall. So the proportions match closely while the absolute amounts do not. That is a real caveat and I am not going to paper over it. But the proportion is the thing being quoted at you, and on the proportion, the placebo group is right there alongside the drug.
So should I just stop worrying?
No. And this is where I want to be careful, because I have watched this conversation swing from panic to dismissal and neither one helps you.
Everything above tells you that GLP-1s are not uniquely destroying your muscle. It does not tell you that lean mass loss is fine. Losing 10 pounds of lean tissue in your fifties matters, because you were already fighting an uphill battle before you started.
Consider what is happening to muscle in midlife anyway. Between ages 30 and 50, we lose roughly 3 to 8 percent of muscle mass per decade. After 50, that accelerates to 5 to 10 percent per decade. And estrogen is directly involved. As UCLA Health puts it, the lack of estrogen causes women to lose muscle faster than men, and it affects muscle repair, recovery and rebuilding too. We wrote about this in more detail in our piece on menopause and muscle atrophy (sarcopenia), because it is happening to a lot of us quietly, years before anyone puts a name to it.
So the accurate framing is not "the drug is eating your muscle." It is closer to this: you are in a life stage that is already working against your muscle, and you have chosen an intervention that shrinks you fairly quickly. The proportion of lean mass you lose is normal. The speed and the context are what make it worth managing carefully.
There is also research suggesting the risk is not evenly distributed. At ENDO 2025, Dr. Melanie Haines of Massachusetts General Hospital and Harvard Medical School presented a study of 40 adults over three months. In the semaglutide group, older age, female sex, and lower protein intake were all linked to greater muscle loss.
Older. Female. Under-eating protein. If you are reading this, there is a decent chance you checked at least two of those boxes before breakfast.
That is not a reason to be frightened. It is a reason to be deliberate.
What Ashley Koff said that reframed this for me
I interviewed Ashley Koff, registered dietitian and author of Your Best Shot, about weight health in perimenopause and menopause. She said something that has stayed with me since:
"A medication doesn't cause anyone to lose muscle. That's just not factual. When your operating system doesn't have what it needs, or your efforts are not doing what will help it make or retain muscle, that is when the body loses or doesn't make muscle."
I would put the first part a little more carefully than Ashley does, because a GLP-1 does lead to some lean mass loss, the same way any weight loss does. But her real point stands, and it is the heart of this article: what you eat and how you move decide how much of that loss is muscle you did not need to lose.
Ashley's broader argument is that we need to break up with weight loss as the goal and aim for what she calls weight health. Her point is that we can lose weight and become less healthy doing it, and perimenopause is the clearest example she knows. The goal is not to get smaller. It is to lose fat while keeping bone, muscle, hydration and blood sugar intact.
The protein conversation, with actual numbers
Protein is where you have the most control, and it is the intervention with the strongest evidence behind it.
The 2025 to 2030 Dietary Guidelines for Americans now put the range for adults at 1.2 to 1.6 grams of protein per kilogram of body weight per day, well above the old RDA of 0.8 grams per kilogram. A 2025 joint advisory on nutrition during GLP-1 treatment, from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society, points to the same range during active weight loss.
Let us make that concrete, because grams per kilogram is not how anybody thinks about lunch.
If you weigh 150 pounds, that is roughly 68 kilograms. At 1.2 to 1.6 grams per kilogram, you are looking at about 82 to 109 grams of protein a day. If you weigh 180 pounds, roughly 82 kilograms, you are looking at about 98 to 131 grams a day.
One honest wrinkle: that same advisory notes that if you are carrying a lot of extra weight, doing the math on your full body weight can overshoot what you actually need. If that is you, ask your provider or a dietitian whether to work from a goal weight instead.
If you have been eating the way many of us were taught to eat in the nineties, toast and coffee, a salad, and then most of your protein at dinner, those numbers are going to look impossible at first. They are not. But they do require you to stop treating protein as the thing next to the vegetables and start treating it as the thing you build the meal around.
We go deeper on the arithmetic in more protein: menopause and postmenopause needs, including how to spot protein on a label.
How to actually get it in when your appetite is gone
Here is the practical problem nobody warns you about. GLP-1s work partly by making you less hungry. That is the point. But protein is the most filling macronutrient, which means it is the one your reduced appetite fights hardest.
I talked this through with Natalie Bean, a nutrition and fitness coach with 31 years of practice who now holds a GLP-1 certification and works with clients on these medications daily. Her guidance was refreshingly specific.
Protein first, every single meal. Physically eat it before anything else on the plate. When you have three good bites of capacity, they should go to the chicken, not the rice. Natalie's baseline for women in perimenopause and menopause is 25 to 30 grams per meal, and she pushes that toward 35 to 40 grams for clients on a GLP-1.
Eat every two to three hours, in smaller amounts. Trying to bank your whole day's protein at dinner does not work on a GLP-1. As Natalie put it, you will get an upset stomach, you will get heartburn, and you will not sleep well. Slowed gastric emptying means volume is your enemy and frequency is your friend.
Get consistent before you get creative. This was the piece of advice I did not expect. Natalie has found that clients in our age range do better with a set rotation of meals than with maximum variety. Two breakfast options, three lunches, rotating. Fewer decisions, fewer misses, and when something is not working you can actually tell which variable to change. Variety for gut diversity matters, and you can build it back in once the foundation is holding.
Hydration is not a footnote. Aim for roughly half your body weight in ounces of water. Dehydration on these medications shows up as dizziness and lightheadedness surprisingly fast, and it makes every gastrointestinal side effect worse.
Editor's note on this interview: In the opening moments of this video, and in our original video description, we said a GLP-1 can cost you "25 to 40 percent of your muscle mass." That is the wrong denominator, and we are correcting it here rather than quietly leaving it. The accurate statement is that approximately 25 to 40 percent of the total weight lost may come from lean mass, which is how Mayo Clinic frames it and how the underlying trial data reads. Natalie's actual guidance in the interview, including her figures of 2.4 to 4 pounds of lean mass in context, reflects the correct understanding. It was the wording in the cold open that slipped, not the nutrition advice that follows. We are also correcting the video itself.
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The rest of the plate
Protein gets the headline, but it does not work alone.
Fiber. Slower digestion plus smaller meals plus not enough water can leave things moving a lot more slowly than you are used to, and plenty of women on these medications deal with that quietly. Natalie called fiber a whole topic of its own, and she is right. Start with food: beans, lentils, oats, berries and vegetables, added gradually and with plenty of water. And if your digestion is giving you real trouble on a GLP-1, tell the provider who prescribed it. That is something they need to know.
Good fats. Fat slows the release of sugar into your bloodstream and helps you absorb fat-soluble vitamins. Olive oil, avocado, nuts, and fatty fish. Our Omega 3-T is there for the women who are not eating fish two or three times a week, which is most of us.
Low glycemic carbohydrates. Please do not cut carbohydrates out. We are more prone to insulin resistance in this phase of life, and the answer is choosing better carbohydrates, not eliminating the category. Sweet potato, squash, beans, lentils, oats, berries.
Pair everything. If you are having fruit, have it with protein or fat. Apple with almonds, not apple alone. That slows the release and keeps you from being hungry again in thirty minutes, which is exactly the moment when a poor decision gets made.
Food is not the whole job
You can hit your protein target perfectly and still lose more muscle than you needed to, because protein is the raw material and resistance training is the signal. Without the signal, your body has no particular reason to keep the tissue.
Current guidance points to strength training at least three times a week, alongside about 150 minutes of aerobic activity. Dr. Sangeeta Kashyap of NewYork-Presbyterian and Weill Cornell put the stakes plainly: muscle drives metabolism, glucose control and strength, and excessive loss slows metabolism, increases frailty, and raises fall and fracture risk.
Two things worth clearing up, because both come up constantly in our community:
Cardio is not the enemy. There has been a swing so far toward strength training that women are now afraid to walk briskly in case they spike cortisol. Natalie's response to this was blunt: you raise cortisol walking up the stairs. Thirty minutes of movement a day is good for your heart and good for your head, and a calmer head is its own cortisol intervention.
Body weight counts. If weights are not accessible to you right now, for any reason, your own body is legitimate resistance. Start there. Our guide to menopause, exercise and fitness walks through what this can look like when you are beginning.
The supplement conversation, honestly
A few things have research behind them here and a lot of things do not, so let me separate them.
Creatine monohydrate has the most interesting evidence for muscle and strength in this age group, and it works alongside resistance training rather than instead of it. We wrote a full piece on creatine and menopause covering what the science actually supports and where it is still thin.
Magnesium supports normal muscle function and energy metabolism, and many women in perimenopause and menopause are not getting enough to begin with. Our Magnesium Bisglycinate is the gentle, well-absorbed form.
Vitamin D, ideally with K2. Mayo Clinic's GLP-1 nutrition guide recommends baseline lab testing for vitamin D, B12, iron, calcium and magnesium when starting a GLP-1, with follow-up within three to six months. That is a genuinely useful piece of advice and almost nobody is given it.
And the honest caveat: when your appetite drops that sharply, you become deficient faster than you expect, because you are simply eating less of everything. Supplements are there to supplement a diet, not to replace the eating you are no longer doing.
As always, this is information, not a prescription. Please talk to your own healthcare provider about what is right for you, particularly if you have kidney concerns, take other medications, or are being monitored for anything.
These statements have not been evaluated by the Food and Drug Administration. Morphus products are not intended to diagnose, treat, cure, or prevent any disease.
What to track instead of the scale
If lean mass is the thing you are trying to protect, the bathroom scale is close to useless for telling you whether it is working. It gives you one number and no composition.
Better signals:
- Strength markers. Can you still carry the same groceries, get off the floor, climb the same stairs without stopping? Early research suggests function can hold even when size drops, so function is worth measuring directly.
- How your clothes fit, and inches, rather than pounds.
- A DXA scan if it is available and affordable to you. It is the only way to actually see the fat and lean breakdown.
- Bloodwork, including the micronutrients listed above.
- Energy and recovery. If you are consistently wrecked for two days after a light workout, something in the fueling is not adding up.
Bottom line
The scary statistic going around menopause social media is real but is being quoted with the wrong denominator, and that one error is causing a lot of unnecessary fear. Roughly 25 to 40 percent of the weight you lose on a GLP-1 comes from lean mass, and the SURMOUNT-1 placebo group lost lean mass in almost exactly the same proportion. Losing weight costs lean tissue. That is true of every method humans have ever used.
What makes this worth taking seriously is not the medication. It is that you are doing it in a decade when estrogen is already working against your muscle, and you are doing it faster than a body typically would on its own.
So protect it deliberately. Protein at every meal, ahead of everything else on the plate. Enough water. Fiber so your digestion keeps up. Resistance training three times a week so your body has a reason to hold on to what you are feeding it. And a measurement more useful than a number on a scale.
Strong, fed, and steady is the goal. That was true before GLP-1s existed and it is still true now.
Your GLP-1 and muscle questions, answered
Will I lose 25 to 40 percent of my muscle on a GLP-1? No. That figure refers to the proportion of the weight you lose that comes from lean mass, not the proportion of your existing muscle. If you lose 30 pounds and roughly a third is lean tissue, that is around 10 pounds of lean mass, which includes water and connective tissue as well as muscle. It is worth managing. It is not the catastrophe the phrasing suggests.
Do GLP-1s cause more muscle loss than dieting? The evidence so far says not disproportionately. In the SURMOUNT-1 body composition substudy, the tirzepatide group lost weight that was 26 percent lean mass and the placebo group lost weight that was 25 percent lean mass. A small 2026 study in Cell Reports Medicine, 10 people over 12 weeks, pointed the same way and found strength held steady even when muscle size decreased.
How much protein should I eat on a GLP-1 in menopause? The 2025 to 2030 Dietary Guidelines for Americans put the range for adults at 1.2 to 1.6 grams per kilogram of body weight daily. For a 150 pound woman that is roughly 82 to 109 grams a day. Spread it across the day rather than concentrating it at dinner, and eat it first at each meal, because your appetite will run out before your plate does.
Will I gain the weight back if I stop? It is common, and the mechanism is not mysterious. When the medication comes off, appetite signaling returns and so does food noise. Natalie Bean described a client on a maintenance dose who regained seven to eight pounds in about two weeks for exactly this reason. This is precisely why learning to eat well while you are on it matters so much. The medication is a tool, not a replacement for the skill.
Is resistance training really necessary, or is protein enough? Both are necessary and they do different jobs. Protein supplies the raw material. Resistance training provides the signal that tells your body the tissue is worth keeping. Guidelines suggest strength training at least three times a week. If you can only do one thing consistently, do not make it a choice between them, make it a smaller version of both.
Should I avoid cardio because of cortisol? No. This worry has gotten out of proportion. Everyday movement, including thirty minutes of walking, is good for your heart and your head. Strength training deserves its place in the week, and it does not need to displace walking to earn it.
