For years, the weight loss industry has buzzed with the latest craze — Ozempic. It’s in TV commercials with ear-worm jingles. It’s on social media as influencers show off their transformation thanks to the drug. And it’s in rumors that circulate each time a celebrity appears with a new physique.
Ozempic and its counterparts, such as Wegovy, are GLP-1 drugs, a new class of drugs that are changing the game for obesity treatment. No longer are diet and exercise or surgery the only options for someone looking to shed more than a few pounds. With a weekly injection or, more recently, a pill, people have hope that their weight loss journey might finally reach a successful destination.
Gina Leinninger, a Red Cedar Distinguished Professor of physiology in the College of Natural Science, specializes in obesity research. Below, she provides insights on how these drugs work and why losing weight isn’t a simple matter.
Glucagon-Like Peptide-1, or GLP-1, receptor agonists are injections and pills that modulate your appetite. They were initially used for Type 2 diabetes because they make the pancreas secrete more insulin, the hormone that cues your body to take up glucose from the blood. GLP-1 also acts in the gastric system and in the brain to suppress appetite. Together, this makes a powerful combo to manage blood glucose and support weight loss, which is why it is very helpful for treating Type 2 diabetes.
Interestingly, your body naturally produces a little GLP-1, but it is degraded too quickly to be effective. Scientists studied how GLP-1 works to make a more stable version that elicits the same beneficial effects, known as GLP-1 receptor agonists. An agonist is a substance that activates a receptor in the body, essentially turning on a biological signal. This is an important example of how scientific research leads to life-changing treatments for disease.
One of my colleagues calls them forever drugs. And that’s real. You can only get the benefits if you keep taking them. Once you stop, the weight loss effects reverse within a month. Individuals with heart disease are on medications for the rest of their lives. If we are really going to think about obesity as a disease, we must treat it the same way.
Our bodies have evolved to defend our body weight. Our brains use hormones to determine our energy status, and they modify behavior accordingly. If the brain senses we don’t have enough energy, it promotes eating. If it senses we have too much energy, it might tell us to tamp down on eating a bit. But it’s much better at helping us respond to a caloric deficit than to a caloric surplus. It’s very easy in our modern age to take in more calories than we intend to. Then, when you gain weight, your body’s energy balance shifts and your brain says, let’s defend this weight now. The brain is good at keeping your weight static or letting you gain a few pounds. This was probably helpful back when we were hunters and gatherers and didn’t know where our next meal was coming from.
The other side of the coin is, once you’ve lost weight but then gain some back, your body doesn’t want to defend the lower weight. We’ve seen studies on individuals from the show “The Biggest Loser” where, once the show was over, former contestants gained weight even if they kept exercising two hours a day and maintained their diet. That’s because the brain and the body actively don’t want to keep that weight off.
I think it would be great if we all ate better, not for weight loss but for general health. We recognize it’s important to get our fruits and vegetables. While diet and exercise are still the most widely recommended treatment for obesity, we know that they just often don’t work because individuals’ altered brain chemistry doesn’t allow them to work. We need jump-starters like GLP-1 receptor antagonists. They can help retrain the brain and, along with healthy eating habits and exercise, support long-term weight loss. Maybe you do need to be on the drug forever, but maybe you can go down to a fairly low maintenance dose. The drugs are meant to help individuals develop and maintain healthy habits that support a healthy weight for life.
I don’t love it, particularly because it’s taking some of the market share away from individuals who really do need it to protect their lives. For example, my husband has a heart condition and was prescribed Ozempic to help deal with it because it has really great cardio-protective effects. Yet he couldn’t get it as someone with a known heart condition. The drug was in short supply because of people taking it to lose a few pounds, which could be done with diet and exercise. I understand the temptation, but unless it becomes so widely available that that’s an option, I think these first need to be reserved for the many individuals who genuinely need them. We also need to figure out how to make them more accessible because the drugs currently cost up to $1,000 a month.
That’s tricky. It took the industry about 20 years after lap band surgeries were developed before we got enough critical mass of data to see the long-term effects. I think our understanding of the real clinical effects of the GLP-1 receptor agonist is yet to come. That said, they do appear to be very safe by all the profiles that we can tell. I wish no ill will. I hope it continues to be wonderful and positive.