Does Ozempic cause muscle loss?

When you think about losing weight, you probably mostly think about fat. That makes sense, because that’s what you want to get rid of. But it’s precisely your muscles that deserve extra attention here.

The more muscle mass you have, the more energy (calories) you burn, even at rest.

Keeping your muscles while losing weight helps you lose fat more effectively and maintain your target weight.

Want to lose weight? Then it’s just as important to move enough and get enoughproteinas it is to eat fewer calories.

Before we dive deeper into muscle loss, a quick biology refresher comes in handy: what exactly do your muscles do?

A few facts:

• Your body has more than 600 muscles, each with its own function.

• There are three types of muscle: skeletal muscles, smooth muscles and the heart muscle.

• Skeletal muscles can be controlled consciously and provide movement, posture and strength.

• Smooth muscles work unconsciously and regulate processes such as your digestion and blood flow.

• Your heart muscle also works unconsciously; it pumps blood through your body day and night and is considered the hardest-working muscle you have.

All your muscles contribute to your daily functioning and health.

Strong muscles not only improve your mobility and balance, but also help, for example, to keep your blood sugar stable, prevent excess weight and support your immune system.

Just like the rest of your body, muscles work best when you eat healthily and exercise regularly.

What many people don’t know is that when you see the number on the scales go down, you have most likely lost not only fat but also muscle mass. Here’s how that works.

Muscles are constantly on the move, even when you aren’t. Every day, 1 to 2% of your muscle mass is broken down and rebuilt. That means your muscles renew themselves completely roughly every 50 to 100 days.

Your muscle tissue cleverly adapts to the load you put on it: more movement = stronger muscles. But the reverse is also true. If your muscles have less to do, they break down at lightning speed.

That’s where the risk lies

From the age of 30, you lose on average 1% of your muscle mass per year. By the time you’re 80, you may have lost half of what you once had, unless you stay actively moving [1].

Illness or inactivity speeds up muscle breakdown considerably. Just five days of bed rest can lead to 3.5% muscle mass loss in one leg, and up to 10% loss of strength. After two weeks, that can rise to 8.5% muscle loss [1].

Losing weight can speed this up

Losing weight can accelerate the process of muscle breakdown.Medicinessuch asMounjaroandOzempichelp effectively with weight loss, but that weight loss doesn’t consist of fat alone. Research shows that 20% to 50% of the weight lost withGLP-1 medicationcomes from fat-free mass, including muscle [2].

This risk is not limited tolosing weight with injections. Muscle loss is also a well-known effect of weight loss without medication, think of a strict diet or bariatric surgery.

People with a lower BMI are especially at risk: when less fat is available, the body draws energy from muscle tissue more quickly. That increases the chance of a less favourable body composition. In other words, less muscle mass, but just as much (or more) fat than before.

That is one of the reasons the medication is only prescribed from a BMI of 27.

Muscle loss is not listed as an official side effect ofOzempic. The concern is more about the effect of rapid, significant weight loss in general.

As we mentioned, weight loss rarely comes purely from fat mass. When you lose weight you lose fat, but also fat-free mass, such as muscle [3]. Exactly how much varies from person to person and depends on factors such as your age, health, diet and exercise habits.

How much muscle loss occurs with Ozempic?

Muscle loss also occurs with GLP-1 medication such as Ozempic andWegovy, although it’s hard to put a single percentage on it.

For instance, the study we mentioned above showed that 20% to 50% of the weight lost with GLP-1 medication comes from fat-free mass, including muscle.

But there has also been an analysis that looked at six studies with a total of 1.541 adults with overweight or obesity [4]. These showed a clear reduction in weight, mainly through fat loss. In some cases fat-free mass remained stable, but in other studies it made up as much as 40% of the total weight loss.

Strikingly, the proportion of fat-free mass relative to total body weight still increased, a sign that body composition improved on balance.

Why muscle loss is a problem (for more than just your strength)

Muscles do more than provide strength or a toned look. They regulate your metabolism, keep your blood sugar stable, and are essential for recovery from illness or surgery. In short: your muscle mass is an important foundation for your overall health.

If you lose muscle mass, you lose far more than just strength.

Less muscle = more risk

Muscle mass affects your whole health. Less muscle mass means:

• Less strength and stability

• A higher risk of falls

• Slower recovery from illness or after surgery

• A greater chance of regaining fat mass after you stop losing weight

• A lower resting metabolism (you burn fewer calories at rest)

• Getting tired more quickly during daily activities

• Poorer posture, with a risk of back or joint problems

• Reduced bone density

• Poorer blood sugar regulation

Extra important during weight loss

When your muscle mass decreases, your metabolism slows down. That not only makes it harder to keep losing fat, but also makes you more likely to regain weight after your weight-loss journey. And mainly as fat, not muscle mass.

That’s why preserving muscle while losing weight is hugely important. It helps you stay stronger, healthier and more stable. Not just now, but in the long term too.

And now the good news: you can prevent muscle loss. You only need to do 2 things: stay active and eat enough protein.

1. Strength training is key

To maintain your muscle mass, you have to move. There’s no way around it. The physical activity guidelines of the Dutch Ministry of Health, Welfare and Sport (VWS) prescribe the following:

• At least 150 – 300 minutes per week of moderately intensive activity (such as brisk walking, cycling, gentle swimming), spread over several days

• Muscle- and bone-strengthening activities at least 2 times per week.

• For people aged 65 and over, the advice is to combine this with balance exercises: on average 2.5 hours of moderately intensive activity per week, muscle- and bone-strengthening exercises 2 x per week, and alternating all of this with exercises to improve balance.

Strength training is the most effective way to maintain and increase muscle mass, but aerobic training also helps you keep muscle mass during weight loss [5].

Want to start exercising, but not sure what the options are? Here are a few examples:

Strength training

• Weightlifting

• Using resistance bands

• Bodyweight exercises (for example push-ups and sit-ups)

• Activities such as heavy gardening

Aerobic training

• Walking, jogging, cycling, swimming

• Dancing

• Climbing stairs

2. Protein, protein, protein

Muscles are largely made up of protein, and to maintain them, your body needs enough high-quality protein every day.

Experts advise getting around 20-30 grams of protein per meal. For active adults and older people, that comes to roughly 1.2 to 1.6 grams of protein per kilo of body weight per day.

A study from 2013 showed that people who consumed 1.6 g/kg of protein lost more fat and less muscle mass while losing weight than those who followed the standard guideline of 0.8 g/kg [6].

Research from 2021 also confirms that a higher protein intake can help to significantly limit muscle loss during weight loss [7].

Healthy sources of protein include:

• Lean meat (such as chicken breast)

• Fish

• Greek yoghurt and quark

• Beans, peas and lentils

• Nuts and seeds

Not necessarily. It is important, though, to be aware of the risk and to adjust yourlifestyleto minimise possible muscle loss.

Keep eating enough protein, keep moving, make sure you get a goodnight’s sleepand don’t focus only on the scales, but also on preserving your muscle.

When you stop using GLP-1 medication, your appetite often increases again. Combined with reduced muscle mass, that can mean you regain weight, but mainly as fat.

And, because muscles largely determine your resting metabolism, you burn fewer calories at rest than before you started.

Without the right approach, an unfavourable body composition develops: more fat, less muscle. This is why preserving muscle during and after the use of weight-loss medication is important for lasting results.

Does Ozempic, or other weight-loss medication, cause muscle loss? Not directly, but the rapid weight loss that comes with it can.

With weight loss, whatever the method, muscle loss is a risk and preserving muscle mass is an important point of attention

Because muscles are not only important for your strength or appearance, but are a key pillar of your health and weight.

By training regularly and eating a protein-rich diet, you can maintain your muscles or even make them grow.

Want to know whether weight-loss medication is right for you? At Wellis we look at the whole picture: your body, your goals, your health.Fill in our short questionnaireand discover what’s possible for you.

Will I lose muscle mass if I use Ozempic?

Yes, that can happen. It isn’t caused directly by Ozempic, but happens with (rapid) weight loss in general.

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Is muscle loss dangerous?

In some cases, yes. Too much muscle loss can affect your strength, energy levels, health and even your mobility, especially as you get older. But with the right diet and exercise, you can prevent muscle loss.

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Can you prevent muscle loss while using Ozempic?

Absolutely! Two words: protein and strength training. Make sure you get enough protein (think chicken, fish, beans, nuts) and do resistance training (such as weightlifting or bodyweight exercises). This helps keep your muscles strong, even during weight loss.

Do all GLP-1 medications have the same effect?

Yes, the effect is similar with medicines such as Wegovy, Mounjaro and Saxenda. Anything that causes rapid weight loss can affect your muscle mass. That includes methods such as a low-calorie diet or bariatric surgery.

How do I know if I’m losing muscle mass?

The tricky part is: you don’t feel it straight away. Muscle loss often happens gradually and unnoticed. But there are signs you can look out for:

• You notice your strength decreasing, for example when climbing stairs or lifting something.

• You get tired more quickly during exertion than before.

• You’re losing weight, but your body shape hardly changes, for example: you stay ‘soft’ or don’t lose any waist.

• Your resting metabolism drops and you notice you regain weight more quickly.

Want to know for sure? Then you can have your body composition measured with a special scale (BIA measurement), a DEXA scan or through a dietitian or physiotherapist.

Can I build muscle while using Ozempic?

Definitely. Building muscle is possible, even while losing weight. You do that through consistent training, enough protein and enough sleep.

Do I need to take supplements to prevent muscle loss?

Not necessarily. If you get enough protein from your food, supplements are usually not needed. But in some cases, such as with a vegan diet or an increased protein requirement, a protein shake or BCAA supplement can help. Discuss it with your doctor or a dietitian.

How much protein should I eat per day?

The basic recommendation is 0.8 grams per kilo of body weight. But during weight loss it can be worthwhile to go towards 1.2-1.6 grams per kilo, to better protect your muscle mass.

Does strength training slow down my weight loss?

No, in fact it can improve it. Your body burns more calories when you have more muscle mass. You may see the number on the scales drop a little more slowly (because muscle is heavier than fat), but you lose more fat and keep a leaner, healthier and stronger body. And that’s what it’s ultimately about.

Which is better against muscle loss: cardio or strength training?

Both forms of exercise have their benefits, but when it comes to preserving or building muscle, strength training is number one. Cardio does a lot of good for your heart and helps burn fat, but without resistance training you run the risk of losing muscle mass as well as fat while losing weight. Want to become leaner, stronger and healthier? Then strength training is your best friend.

Is losing a little muscle mass really that bad?

That depends. A small amount of muscle loss is usually no cause for panic, especially if you otherwise feel fit. But prolonged or excessive loss can affect your energy levels, metabolism and general health. So keep an eye on it, especially if you’re older or don’t move much.