The medications Ozempic (semaglutide), Wegovy (semaglutide) and Mounjaro (tirzepatide) continue to be in high demand as people turn to these medications for weight loss, heart health and Type 2 diabetes control. However, taking Ozempic and other GLP-1 drugs for weight loss might not be for everyone. 

Some rare but serious Ozempic side effects such as gastroparesis and intestinal blockages have led to people filing Ozempic lawsuits

In this Q&A, New York City triple board-certified weight loss and obesity physician Dr. Sue Decotiis discusses Ozempic’s effectiveness, plus how it compares to Mounjaro and some of the drug’s common side effects.

Q: How effective is Ozempic for weight loss? 

Studies have shown that people can lose up to 15% of their body weight within a year while using Ozempic while patients have lost up to 20% and more with Mounjaro. Of course, results always vary, but people that have not been as successful are usually people who are not getting adequate amount of water. 

After discontinuation of the medication, long-term results can vary based on the type of follow-up care they receive. Patients should monitor their body composition. It’s very important because it will give you a more accurate idea of what’s going on inside your body. If a patient loses a lot of muscle, then chances are they’re going to gain weight back. In my practice, patients tend to do much better when slowly tapering off after they reach their goal.

Q: Who is qualified to use Ozempic for weight loss? 

Number one, you’d want a patient to be overweight. And that means that their BMI is, in theory, over 27. A BMI between 27 and 30 is considered to be overweight. Over 30 is considered to be obese.

Number two, you’d want to make sure that they’ve tried to take the weight off on their own legitimately.

You’d want to ask them, “What is your lifestyle like? What kind of foods do you eat? Are you eating a lot of junk food? Are you eating a lot of processed food? Are you exercising? Is this happening because you were really stressed?” Maybe they gained a lot of weight during COVID-19, and they never got their act together again. You take a good history from the patient. 

You also want to make sure that there aren’t any other underlying psychological problems going on. For example, does this patient have an eating disorder? 

The whole point is that it’s not meant to be a magic pill for everybody because if habits are bad, they’re never going to get better by just taking a drug. 

Q: There are some questions about people regaining weight after stopping Ozempic. What can you say about that? 

Well, it doesn’t happen in my practice. And I don’t want to sound arrogant, but the difference is that, in my practice, we follow everybody with a body composition scale. I’m looking for fat loss. I don’t want to just see that they’ve lost weight and their BMI has gone down. It is essential that a physician follows the body composition.

I need to know how much fat this patient is losing. I can look at fat, muscle and water in the body. If you lose muscle, that’s a very degenerative situation, of course. True weight loss means fat loss. And that has to be documented on a scale.

I think patients are not being told that it is essential to be well-hydrated. If you’re not hydrated, the body will not burn fat. Water is tied to weight loss. When you burn fat, every fat cell is mostly water. So, in essence, when you’re fat-burning, you’re actually dehydrating yourself. If you don’t replace that water, what’s the body going to do? The body goes, “Whoa, I can’t burn fat. And I’m on caloric deprivation. So, I think I’m going to burn some muscle.”

My patients have maintained muscle, and they’ve maintained hydration and nutrition. A lot of these patients don’t gain weight back because I keep them on a lower dose for a longer period of time.

Q: How does Ozempic work to help people lose weight?

The reason why these drugs work is that most people who can’t lose weight have a problem with insulin resistance. It’s not necessarily always just calories in calories out.

[Think] about a young person, a child, somebody under the age of 35 or 40. When we’re young, we can take off weight in a second, right? We can’t do that as we get older. Why is that? Well, because insulin is our major fat-burning hormone. And it just doesn’t work as well, like a lot of our other hormones don’t work as well as we get older.

So, the reason why this drug works is not just the fact that it depresses appetite, it’s that it gets insulin to work better. And that’s what GLP-1 is about. GLP-1 is a receptor that’s in the intestine and also has receptors in the brain.

Q: Who shouldn’t use Ozempic to lose weight? 

People who haven’t corrected poor eating habits. I think you have to be very careful when prescribing it for children or teens. Because with any pediatric patient, you really have to go through the whole algorithm of what they’re eating. You have to really speak to the parents and go through what’s in the refrigerator. You have to make sure they’re getting physical exercise.

You don’t want to put somebody on this drug that has disordered eating. A lot of those people who are worried about Ozempic face and losing too much weight may have an eating disorder, and they took it too far. And the doctor wasn’t monitoring them. The doctor was just writing a prescription, calling it into the pharmacy.

Q: What are Ozempic face and Ozempic neck? 

If you lose muscle, because you’re not having your body composition monitored, that’s a possibility. Typically, people with Ozempic face and Ozempic neck have probably lost too much weight. The skin is sagging around the face and the neck.

Underneath the epidermis, you have the dermis. And that’s where you have supporting tissues and a lot of collagen that supports the skin. Underneath that you have muscle.

And as we get older, you lose muscle in your arms and your legs and you can lose muscle in your face. And your neck or anywhere, really. As we age, we lose collagen. We even lose a little bone and muscle, depending on the shape of our faces.

What masks it is being heavy. So, when you have a lot of fat in your face that masks it, you don’t know that it’s there. So, people who have been heavy probably have more facial aging than people who have been thin, but they don’t see it until they take the weight off. So that’s what a lot of what Ozempic face is.

Q: What are the main differences between Ozempic, Wegovy and Mounjaro? 

Ozempic and Wegovy are the same drug. The dosage for Wegovy is a little higher, but other than that, it’s the same. Zepbound is an FDA-approved weight loss drug that has the same active ingredient as Mounjaro. Those are also pretty much exactly the same.

But the other thing about Mounjaro, the reason why it’s more effective, is that it works on two receptors. It doesn’t just work on GLP-1, which is what Ozempic does. It works on GIP, gastric inhibitory polypeptide. I think that’s the difference. That’s why people get more fat loss with that. And that’s why it continues working after a while. I prescribe Mounjaro more often because it works better, and I believe there are fewer side effects.

Q: What is your opinion on using compounded formulas?

Compounds are great when they’re high quality because then you can customize the dose. I think the good compounders probably have higher quality than the big pharma drugs.

But of course, there are a lot of bad actors out there. But you don’t want to throw the baby out with the bath water, you know? Most compounders are legitimate because they have a lot to lose. Some of the people who run these compounding pharmacies were scientists who invented some of these medications. 

The last thing they would want to do is compromise their reputation and have their company shut down, because the FDA will shut these companies down at the drop of a hat.

Q: What are the downsides to taking these drugs for weight loss? 

I think the biggest downside is not being cared for properly by your physician. Not getting your body composition monitored, not losing fat, not drinking enough water, losing muscle.

And then also, when you get to your ideal weight — your ideal body fat — realize, too, that the body resets at a lower metabolic rate after you lose a lot of weight. That’s why a lot of times we gain the weight back. However, the body will reset at a higher metabolic rate if it feels that everything is copacetic.

And nobody should quit these drugs cold turkey. So, we taper them slowly, and we’re following their body composition. That helps me determine how slowly to taper the drug.

Q: What are the interesting things you have noticed when using Ozempic or Mounjaro for weight loss in your patients?

The interesting thing is that this is where women kind of have an edge. It seems that female patients lose more weight on these GLP-1 drugs than men. Because normally women don’t, you know, we don’t have as much muscle. And if you and your male friend go on a diet with the same amount of calories, he’s going to lose a ton of weight and you’re not.

I think estrogen is a modulator. So, I think having estrogen really helps you. And it makes the drugs work better. A lot of my male patients have hit a wall and a lot of the women have not. It’s still highly effective for men. I’m not saying it isn’t, I’m just saying it’s very interesting that we see that gender difference.

Q: What Ozempic side effects have you seen in your patient group?

The most common side effects would be GI side effects. Nausea, vomiting, a feeling of fullness. Maybe some reflux, like regurgitation, like you taste your food a little bit after you eat. Those can be dose-related. But most patients get used to the drug.

The side effects can be managed with antacids and by not eating a lot of fatty foods. We give people a pretty low-fat diet to follow. We usually put people on two meals a day, like an intermittent fasting protocol where they’re eating within a window of time. And that’s also good to help insulin work too.

The other issue, of course, is hydration. People who are dehydrated really feel crummy. They kind of feel hungover. They feel tired, lightheaded, nauseous, like you have a hangover.

Q: Are there people who have had to stop taking the drugs because the side effects have been too severe for them? 

Very few. And most of those people just weren’t drinking water. Most people don’t stop it.

Q: What’s the most important thing that you would tell people about when they’re thinking about using these drugs for weight loss? 

Make sure you’ve tried to lose it on your own. Make sure that you’re moving and that you’re eating healthy food. But once you’ve done that, don’t blame yourself.

Especially after a certain age or if there are genetic factors, it’s not just lifestyle. It’s not just calories in calories out. You can have the best diet ever, and we see this as people get older. People entering perimenopause, menopause, or men with low testosterone get a little older and can’t maintain the body weight that they used to.

Killing themselves at the gym is not going to work if insulin isn’t working. When you’re exercising, you need insulin to work well. If it isn’t, the body is going to lower its metabolic rate. You’re going to gain weight at the gym.

If insulin is really not working, I think these drugs are the answer. But you can’t stop cold turkey. The drugs should be tapered. And you must make sure that you’re getting your body fat measured.