The buzz around weight-loss drugs Ozempic and Wegovy became a roar in 2023. Celebrities such as Oprah and Tracy Morgan touted their benefits. So did TikTokers, physicians and, well, seemingly everyone.
But the class of drugs that Ozempic and Wegovy belong to is relatively new—only about 10 years old—and there’s still much to learn. Both drugs contain semaglutide and both are marketed by Danish drugmaker Novo Nordisk. Both are administered via weekly injections.
Wegovy and Ozempic mimic the hormone GLP-1 (glucagon-like peptide-1), which regulates satiety in our bodies. In short, the drugs decrease appetite, so people who use them feel less hungry and eat less. They do this by stimulating the release of insulin to control blood sugar. Indeed, Novo Nordisk initially developed Ozempic to treat type 2 diabetes, and the Food and Drug Administration approved it for that use in 2017.
It wasn’t long before patients taking Ozempic noticed that it contributed to weight loss, too. The company developed Wegovy, which has a higher dose of semaglutide, specifically to address obesity. About 40% of American adults and about 20% of children are obese, according to the Centers for Disease Control and Prevention. The FDA approved Wegovy for chronic weight management in adults and children older than 12 in 2021. (Both drugs may soon be marketed to kids as young as 6.)
Demand is high: In the last three months of 2022, health care providers wrote more than 9 million prescriptions for the drugs, according to data analytics company Trilliant Health. Insurance coverage varies by location and patient eligibility; the drugs can cost about $1,000 per month without insurance. Currently, there are no generic versions.
To learn more about Ozempic and Wegovy, we spoke with Arshad Ali, a physician specializing in obesity and internal medicine at VHC Health. The following conversation was edited for clarity and length.
How does semaglutide in Ozempic and Wegovy work?
One of the things it does is tell the stomach to slow down digestion. Second, when you eat and the food enters the intestine, your blood sugar level starts to rise. That’s normal, because you’re absorbing the energy from the food, but you need something to bring that sugar level down. GLP-1 tells your pancreas to make more insulin, which is the hormone that brings your sugar down. This is why these drugs are useful to treat diabetes. Third, the drug mimics a specific part of the brain called the hypothalamus, which tells your brain you feel full; it increases the satiety signal in your brain. So, when you’re taking these drugs, it’s almost like the brain thinks you ate something even though you didn’t.
Who’s a candidate for these drugs?
When we’re talking about weight management from a medical perspective, we’re really talking about the treatment of obesity. Obesity is a medical disease, just like diabetes, high blood pressure, high cholesterol and heart disease. We have very specific criteria for identifying issues that require treatment. With these drugs, the metric is typically BMI, or body mass index. For someone who has a BMI higher than 27, combined with a medical condition like high blood pressure, diabetes, etc., these drugs could be indicated. Someone with a BMI over 30, independent of another medical condition, is also a candidate. In that case the patient’s BMI in and of itself would be a strong enough risk factor to use these drugs.
So, you can’t just walk into your doctor’s office and say, “I need to lose 10 pounds for my friend’s wedding. Can I have a prescription?”
These are medical treatments for a medical disease. They shouldn’t be used for something like that. Another really important thing to consider is, this is a chronic disease, just like high blood pressure is a chronic disease. If you give someone medicine because they have high blood pressure and it brings their blood pressure down to normal, they have to keep taking that medication. If they stop, that number will go up. It’s the same thing with using these drugs. Say you take it for a month and it helped you lose 10 pounds. As soon as you stop it, you’re going to feel really hungry and keeping off those 10 pounds is going to be really difficult.
I’ve read that these drugs also help conditions like liver disease and polycystic ovary syndrome. How?
I think that’s where it gets confusing sometimes. If you have medical obesity, there are a lot of good things that happen if you start to regulate the weight and lose a lot of weight. That, in and of itself, improves a lot of things.
What about adverse effects?
Most of them have to do with the action of that hormone, GLP-1, and how it slows the gut down. Imagine your stomach is emptying into the intestine slower and your intestines are moving slower. You can get constipation, nausea, stomachache, acid reflux, and, rarely, vomiting and diarrhea.
Not much is known yet about long-term effects, right?
That’s correct. This class of drugs has been around for about 10 years. We won’t really know until they’ve been around for decades.
Do food choices and exercise matter if these drugs are helping you keep the weight off?
Absolutely. If you just take the medicine and don’t listen to the cues your body’s giving you, you’ll just feel sick all the time and not lose any weight. The key to weight loss is lifestyle change— primarily dietary change. Exercise helps a little bit, but it really comes down to dietary change. It’s important to remember that the drug itself doesn’t cause weight loss. It doesn’t change your metabolism. It doesn’t burn the fat away in the body. It’s a good tool to help you make the lifestyle changes you need to make.