GLP-1 Agonist Explained: Is It Good For Weight Loss?

 

If you have spent time scrolling through TikTok, searching for the latest weight loss tips, you've probably encountered content glorifying GLP-1 agonists. At the moment, these drugs are being called the "secret weapon" for weight loss. However, they often have hidden costs that few people mention.

In this post, we’ll break down what GLP-1 agonists really do for your waistline, what to watch out for, why losing weight isn’t always as simple as injecting medication into your tummy, and answer the question, “Is it good for weight loss?”

What is GLP-1 Agonist

Glucagon-like peptide-1 (GLP-1) agonists are a group of medications used to manage type 2 diabetes (T2DM) and support weight loss in people with obesity. They belong to a broader class of treatments targeting metabolic and endocrine disorders. These medications work by helping lower blood sugar levels and regulating metabolism, making them a key option for those looking to manage diabetes while also taking advantage of potential weight loss effects.

According to the 2023 ADA guidelines, GLP-1 receptor agonists are recommended to help reduce cardiovascular risk. These medications not only lower the likelihood of cardiovascular events and episodes of low blood sugar but also show effectiveness in slowing the progression of chronic kidney disease (CKD), making them a key option for overall metabolic and cardiovascular health.

How GLP-1 Agonists Help With Weight Loss

1. Appetite Control

GLP-1 agonists work by mimicking a hormone that naturally signals your brain when you’re full. By slowing stomach emptying and boosting satiety signals, these medications help curb cravings and reduce overall calorie intake. In simple terms: you feel satisfied with smaller meals, which can make losing weight a little less of a struggle.

2. Metabolic Boost

Besides controlling appetite, GLP-1 agonists help regulate blood sugar and insulin levels, which can prevent fat storage and promote more efficient energy use by our body cells. Through supporting a healthier metabolism, these drugs allow your body to burn calories and fats easily, complementing diet and exercise for sustainable weight loss.

Popular GLP-1 Agonists on the Market

Semaglutide (Ozempic, Wegovy)

Semaglutide is a key GLP-1 agonist, sold as Ozempic and Wegovy. Ozempic helps manage type 2 diabetes, while Wegovy is for weight loss. It works like the natural GLP-1 hormone, boosting insulin and suppressing hunger.

Liraglutide (Saxenda, Victoza)

Liraglutide is another well-known GLP-1 agonist, sold as Saxenda and Victoza. Victoza treats type 2 diabetes, while Saxenda is for weight loss. It helps by making you feel full and reducing hunger as well.

Effectiveness of GLP-1 Agonist on Weight Loss

GLP-1 agonists are considered a key management for weight loss. They have strong clinical backing. These drugs have been studied a lot for weight management, and the results of the studies are promising.

1. Semaglutide

One of the most common GLP-1 agonists for weight loss is semaglutide. In the STEP 1 clinical trial, nearly 2,000 adults with overweight or obesity took either weekly semaglutide injections or a placebo, alongside lifestyle changes. After just over a year, participants on semaglutide lost an average of almost 15% of their body weight—that’s like dropping 30 pounds for someone weighing 200 pounds—compared to only 2-3% in the placebo group. 

What's even more impressive is that 70% of semaglutide users lose at least 10% of their body weight. 

2. Liraglutide

Another notable GLP-1 agonist is liraglutide, which was tested in the SCALE Obesity and Prediabetes trial. Over 3,700 participants with overweight or obesity used daily liraglutide injections along with diet and exercise. After 56 weeks, they lost an average of 8% of their body weight, compared to just 2.6% in the placebo group. Even better, over 60% of liraglutide users lost at least 5% of their weight, proving that this medication can help a majority of people see real results.

The Problem With GLP-1 Agonist

But here's the thing most people don't know or fail to mention. Indeed, they do such a great job at trimming fat, but they seem to do such a good job that they reduce your bone volume and muscle volume too. Not exactly what you wish, right? That's the not-so-fun twist.

1. Muscle Loss

A recent study indicates that a chunk of the weight you lose on GLP-1 drugs can come from muscle. In fact, lean body mass loss can account for 15% to 40% of total weight lost. That means that’s not just fat waving “see you later”—that’s muscle, the stuff you need to open jars, climb stairs, and carry groceries without wincing

A smaller trial presented at ENDO 2025 focused on semaglutide (the active ingredient in Ozempic) and found that users lost about 6.3% of body weight, but they lost a similar amount of lean muscle, especially if their protein intake was low. That’s a hard truth nobody asked for.

2. Bone Loss

In a clinical trial, the once-weekly GLP-1 agonist semaglutide was put under the microscope in adults at high fracture risk. After 52 weeks, participants showed increased bone resorption (meaning more bone breakdown) and decreased bone density in the spine, hip, and tibia—so their skeletons got lighter along with their waistlines. Interestingly, bone mineral formation didn’t budge upwards, so it’s not like semaglutide was secretly turning users into super-strong skeletons. Bottom line: your bones might part ways with some of their strength, even if you're losing weight with flair.

On the brighter side (yes, there is one), a controlled trial in obese women showed that liraglutide actually slowed bone loss after weight reduction—and even boosted markers of bone formation by 16% compared to a non-treated group.

Why Exercise is Your GLP-1’s Best Friend

Your GLP-1 agonist might help shrink your waistline, but without exercise, you risk shrinking your muscles and bones too. That’s a trade you don’t want—let’s see what the science says.

The Liraglutide + Exercise (Denmark Study)

In a year-long Danish trial, researchers took people who had just lost weight on a diet and divided them into four groups: (1) exercise only, (2) liraglutide only, (3) both exercise + liraglutide, and (4) placebo. The results?

• Liraglutide alone: more weight loss, but at the cost of weaker bones.
• Exercise alone: stronger bones, but less weight loss.
• Exercise + liraglutide: participants lost more fat and preserved bone density.

Exercise isn’t just about burning calories—it’s about making your GLP-1 work smarter, not harder. 

Every time you make your body move (whichever it is, whether weightlifting, walking the dog, or dancing in the kitchen at 2 a.m.), you're saying to your muscles, "Hey, don't waste away while the fat drops off." Resistance training and light cardio workouts are the main drivers to preserve your lean muscle mass, which keeps your metabolism whirring along instead of slowing to a crawl like a lazy Wi-Fi connection.

Final Thoughts

GLP-1 agonists can look like the secret to weight loss, but things aren't quite that way. Of course, they make you drop pounds—but lose muscle and bone too if you're not careful.

The real secret? Mixing up these drugs with exercise and smart nutrition. Because the reality is, losing weight isn't about weighing less on the scales—it's about building a healthy, strong body that's ready to take on life's challenges.