PATH TO PEPTIDES OZEMPIC FACE” AND MUSCLE LOSS:

THE BODY COMPOSITION PROBLEM

Up to 25% of weight lost on GLP-1 drugs is muscle, not fat. Why that matters — and what research says about protecting lean mass.

HERE’S A NUMBER THAT SHOULD GET YOUR ATTENTION: STUDIES SHOW THAT UP TO 25% OF THE WEIGHT PEOPLE LOSE ON GLP-1 DRUGS LIKE OZEMPIC AND MOUNJARO IS LEAN MUSCLE MASS — NOT FAT.

That’s the uncomfortable truth behind the headlines. These medications produce impressive weight loss numbers. But the question researchers are now asking is: What kind of weight are people losing? And what are the long-term consequences?

WHY THIS MATTERS

Losing muscle isn’t just a cosmetic issue. Muscle is your body’s metabolic engine. It burns calories even when you’re sleeping. It protects your joints. It keeps your bones strong. And it determines how well you function as you age.1

When you lose a significant amount of muscle along with fat, several problems can develop:Your metabolism slows down. Less muscle means your body burns fewer calories at rest. This makes it harder to keep weight off and easier to regain it — the classic yo-yo effect.2

“Ozempic face” happens. The gaunt, aged appearance that some rapid weight-loss patients develop isn’t from fat loss alone. It’s from loss of muscle and supportive tissue in the face. Facial fat
pads thin out, skin sags, and the result can add years to someone’s appearance.3

Falls and fractures increase. For older adults especially, losing muscle mass increases the risk of falls, fractures, and loss of independence. This is a serious long-term safety concern.4

WHAT THE DATA SHOWS

By the Numbers: In the STEP 1 trial (semaglutide), participants lost an average of 33.7 lbs total. Of that, approximately 8.4 lbs was lean mass — about 25%. In the SURMOUNT-1 trial
(tirzepatide), lean mass loss ranged from 20-33% of total weight lost depending on the dose.5,6

To put this in perspective: when someone loses weight through dieting alone, lean mass typically accounts for about 20-30% of weight lost. GLP-1 drugs fall in a similar range, which means the
muscle loss isn’t necessarily worse than traditional dieting — but because the total weight loss is much larger, the absolute amount of muscle lost is also larger.7

THE SCIENCE: WHY MUSCLE LOSS HAPPENS

When your body faces a large calorie deficit — whether from a drug, a diet, or surgery — it doesn’t just burn stored fat. It also breaks down muscle protein for energy. Your body treats muscle
as an emergency fuel source.8

GLP-1 drugs create a significant calorie deficit by dramatically reducing appetite. People eat 20-40% less food. When protein intake drops along with total calories, the body has even less
raw material to maintain muscle tissue.9

There’s also a less obvious factor: reduced physical activity. Some people on GLP-1 drugs report lower energy levels, especially in the early weeks. If you’re eating less AND moving
less, muscle loss accelerates.

WHAT RESEARCH SAYS ABOUT PROTECTING MUSCLE

The good news: research suggests specific strategies can significantly reduce muscle loss during GLP-1 treatment.

RESISTANCE TRAINING

A landmark study published in JAMA Internal Medicine (the Lundgren study) found that people who combined GLP-1 medication with regular strength training lost nearly the same total weight but preserved significantly more muscle than those who used medication alone.10

The exercise group lost only about 15% of weight as lean mass compared to 25%+ in the medication-only group. Strength training appears to be the single most effective strategy for protecting muscle during rapid weight loss.

HIGH PROTEIN INTAKE

HIGH PROTEIN INTAKE
When you eat less food overall, what you eat matters more. Research consistently shows that higher protein intake helps preserve muscle during weight loss. Current evidence suggests targeting 1.0-1.2 grams of protein per kilogram of body weight daily, spread across meals.11

NEXT-GEN DRUG DESIGN

Drug developers are aware of the muscle loss issue. Some next-generation compounds — like retatrutide (which targets glucagon receptors in addition to GLP-1) — may help the body preferentially burn fat while sparing muscle. Researchers believe the glucagon component could shift the body’s energy use toward fat and away from muscle.12

There’s also research into combining GLP-1 drugs with myostatin inhibitors — compounds that block a protein (myostatin) that limits muscle growth. Early-stage trials of bimagrumab combined with semaglutide showed improved body composition with more fat loss and less muscle loss.13

THE WEIGHT REGAIN PROBLEM

Here’s why muscle loss matters even more long-term: about two-thirds of people regain significant weight within a year of stopping GLP-1 medications.14

But here’s the catch — the weight that comes back is mostly fat, not muscle. So someone who lost 30 lbs (including 8 lbs of muscle) and regains 20 lbs of mostly fat ends up with a worse
body composition than when they started. More fat, less muscle. That’s why building sustainable habits during treatment is so important.

WHAT TO KNOW

KEY TAKEAWAYS:

• Up to 25% of weight lost on GLP-1 drugs can be lean muscle mass.
• “Ozempic face” results from loss of facial muscle and fat tissue — not just fat.
• Muscle loss slows metabolism and can make weight regain more likely.
• Strength training 2-3x/week is the most effective way to protect muscle during treatment.
• High protein intake (~1.0-1.2 g/kg/day) helps preserve lean mass.
• Next-gen drugs like retatrutide may improve the fat-to-muscle loss ratio.
• Regained weight tends to be fat, not muscle — making body composition worse if habits aren’t maintained.
• Work with a healthcare provider and consider a registered dietitian for personalized guidance.

REFERENCES

1. Wolfe RR. The underappreciated role of muscle in health and disease. Am J Clin Nutr. 2006;84(3):475-482.
2. Ravussin E, et al. Reduced rate of energy expenditure as a risk factor for body-weight gain. N Engl J Med. 1988;318(8):467-472.
3. Keaney TC, Alster TS. The digital age of GLP-1 agonists and facial volume loss. Dermatol Surg. 2024;50(1):15-18.
4. Cava E, et al. Preserving healthy muscle during weight loss. Adv Nutr. 2017;8(3):511-519.
5. Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med. 2021;384(11):989-1002.
6. Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity. N Engl J Med. 2022;387(4):327-340.
7. Heymsfield SB, et al. Weight loss composition is one-fourth lean tissue. Am J Clin Nutr. 2014;100(4):996-1002.
8. Carbone JW, et al. Skeletal muscle responses to negative energy balance. Nutrients. 2012;4(8):740-758.
9. Blundell JE, et al. Effects of semaglutide on appetite, energy intake, and food preference. Diabetes Obes Metab. 2023;25(8):2351-2360.
10. Lundgren JR, et al. Healthy weight loss maintenance with exercise, liraglutide, or both. JAMA Intern Med. 2024;184(1):56-66.
11. Mamerow MM, et al. Dietary protein distribution positively influences muscle protein synthesis. J Nutr. 2014;144(6):876-880.
12. Coskun T, et al. LY3437943 (retatrutide), a novel triple GIP/GLP-1/glucagon receptor agonist. Cell Metab. 2022;34(9):1234-1247.
13. Heymsfield SB, et al. Effect of bimagrumab vs placebo on body fat mass among adults with obesity and type 2 diabetes. JAMA Netw Open. 2021;4(1):e2033457.
14. Wilding JPH, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide. Diabetes Obes Metab. 2022;24(8):1553-1564.

FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY

This document is intended solely for educational purposes to increase awareness of emerging scientific research. It does not constitute medical advice and should not be used to make healthcare decisions.Regulatory Status: Semaglutide (Wegovy) and tirzepatide (Zepbound) are FDA-approved for chronic weight management. Retatrutide and bimagrumab are investigational compounds in clinical trials. Information about body composition changes is based on published clinical trial data and is provided for educational purposes only. All healthcare decisions should be made in consultation with qualified medical professionals. This publication is part of an ongoing educational series designed to promote scientific literacy and awareness of developments in health research.