There’s a new class of medications taking over the wellness and medical world, powerful drugs that can help people lose up to a quarter of their body weight. It sounds like a miracle. But beneath the surface, a quieter, more concerning story is emerging.
What’s This About?
A recent paper, “Impact of GLP-1 Receptor Agonist Therapy in Patients High Risk for Sarcopenia,” takes a closer look at what’s really happening beneath the surface when the number on the scale drops quickly, and it’s something every woman in midlife should be paying attention to. The study examines a class of medications known as GLP-1 receptor agonists, widely used for weight loss and diabetes management.
While these drugs are highly effective at driving significant weight loss, researchers set out to answer a more important question: what kind of weight are we actually losing?
When & Who?
Published in 2025, this review pulls together emerging research from multiple clinical studies. It focuses especially on people who are already at higher risk of muscle loss, think older adults, those with chronic illness, or anyone entering midlife where muscle “naturally” starts to decline.
What Did They Find?
Here’s where it gets interesting, and a little concerning.
Yes, these medications can lead to dramatic weight loss – up to 25% of total body weight. But a significant portion of that loss isn’t fat.
It’s muscle! Not a good thing.
In fact, the study found that anywhere from 15% to 40% of the weight lost may come from lean body mass, the muscle that keeps your metabolism strong, blood sugar regulated, your bones supported, and your body resilient as you age.
For women in perimenopause and beyond, this matters even more. Muscle loss (known as sarcopenia) is already accelerating due to hormonal changes. Layer on rapid weight loss, and you could unintentionally speed up frailty, weakness, and metabolic decline.
Why Does It Matter?
Because muscle is everything.
It’s not just about looking toned, it’s about:
- Keeping your metabolism firing
- Supporting bone density
- Preventing falls and fractures
- Maintaining independence as you age
Losing fat? Great. There are loads of benefits that come with lowering excess body fat.
Losing muscle at the same time? That’s where the long-term risks start to creep in.
The researchers highlight that certain groups, especially older adults and those with chronic conditions, may be particularly vulnerable to this accelerated muscle loss.
What Am I Doing About It?
Although I have never tried GLP-1 medications myself, I see many women in our community using them. More importantly, with these women I don’t just talk about weight, I talk about body composition.
If you’re using (or considering) GLP-1 medications, the goal isn’t just to lose weight. It’s to lose fat while preserving and even building muscle. That means:
- Prioritizing protein, not just calories
- Lifting weights, not just doing cardio
- Tracking muscle, not just weight on the scale
Because the real marker of healthy aging isn’t how light you are, it’s how strong you are.
FAQ: Weight Loss, Muscle Loss, and GLP-1 Medications
Can you lose weight on GLP-1 medications without losing muscle?
Yes, but it doesn’t happen automatically. These medications reduce appetite, which often leads to eating less overall, including protein. Without intentional strength training and adequate nutrition, your body will pull from muscle as well as fat.
Why does rapid weight loss increase muscle loss?
When weight drops quickly, the body doesn’t have time to adapt properly. It looks for the fastest energy source, and muscle is metabolically expensive to maintain. Without the right signals, like resistance training and protein intake, your body may break it down.
How do I know if I’m losing muscle instead of fat?
The traditional scale won’t tell you. Signs of muscle loss include feeling weaker, losing strength in workouts, looking “softer” despite weight loss, or noticing reduced stamina. Body composition scans and scales as well as strength tracking give a much clearer picture.
Do I need to change how I exercise while on weight loss medication?
Yes. If anything, strength training becomes more important, not less. Cardio alone won’t protect muscle. Your body needs a clear signal to hold onto muscle, and that signal is resistance training.
Is appetite suppression a risk for muscle loss?
It can be. When you’re less hungry, it’s easy to under-eat protein and total calories. Over time, this can accelerate muscle breakdown, especially in midlife when your body is already more prone to losing muscle.
Are some people more at risk of losing muscle than others?
Yes. Women in perimenopause and menopause, older adults, and those already sedentary or under-eating protein are at higher risk. Hormonal shifts alone already push the body toward muscle loss, so adding rapid weight loss can amplify that effect.
Can you rebuild muscle after losing it during weight loss?
Yes, but it’s harder than maintaining it in the first place. Rebuilding requires consistent strength training, adequate protein, and time. That’s why prevention is always the smarter strategy.
What’s more important for long-term health: weight or muscle?
Muscle, every time. Weight alone doesn’t tell you anything about health. You can be lighter but weaker, or heavier and stronger. For longevity, metabolism, and independence, muscle is the priority. And, yes, we do need body fat for a longer healthier life. Just not too little and not too much.
Should I stop GLP-1 medications if I’m worried about muscle loss?
Not necessarily. These medications can be incredibly helpful tools. The key is using them strategically, with a plan to protect muscle through nutrition, strength training, and monitoring body composition.
GLP-1 medications can be powerful tools, but they’re not magic. Without the right strategy, you may be losing the very thing that keeps you strong, energized, and metabolically healthy.
So the question isn’t just: How much weight are you losing? It’s, what are you losing to get there?
Zora Benhamou is a gerontologist who studies aging and is dedicated to challenging menopause stigma and ageist stereotypes. As the host of the Hack My Age podcast, she focuses on empowering women navigating the menopausal transition through evidence-based techniques that support your 80 year old self.
Reference: Memel, Z., Gold, S. L., Pearlman, M., Muratore, A., & Martindale, R. (2025). Impact of GLP- 1 Receptor Agonist Therapy in Patients High Risk for Sarcopenia. Current Nutrition Reports, 14(1). PubMed.