Billionaire Elon Musk credited it for his dramatic weight loss. Celebrity sites allege that many more A-listers are using it to stay trim. And TikTok is full of influencers showing off their startling before-and-after shots showing off their weight loss after using it.
What is it? A medication called semaglutide, which is sold under different brand names, including Ozempic, approved in 2017 for treating type 2 diabetes, and Wegovy, approved just last year for weight loss.
The buzz about these drugs has created a shortage of both, according to the U.S. Food and Drug Administration, which is expected to last for several months—causing alarm among patients with diabetes who rely on Ozempic to help control their blood sugar. Experts caution that it’s important to understand these are not miracle drugs—and that there are risks to taking them outside of their intended use.
Here’s what you need to know about semaglutide, including how it works and the risks.
What’s the science behind the drug?
Semaglutide helps lower blood sugar by mimicking a hormone that’s naturally secreted when food is consumed, says Ariana Chao, assistant professor at the University of Pennsylvania School of Nursing and medical director at the school’s Center for Weight and Eating Disorders. This medication, administered through injection, helps people feel full for longer, helps regulate appetite, and reduces hunger and cravings.
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There is significant demand for the drug. In 2019, more than 11 percent of the population was diagnosed with diabetes, while more than four in ten adults classified as obese in 2020.
Patients with type 2 diabetes often have impairments in insulin, a hormone that helps break down food and convert it into fuel the body can use, Chao says. Semaglutide signals the pancreas to create more insulin and also lowers glucagon, which helps control blood sugar levels. This can result in weight loss but experts point out that Ozempic has not been approved for that purpose, though semaglutide at a higher dose (Wegovy) has been.
Wegovy is the first drug since 2014 to be approved for chronic weight management. The difference between the two drugs is that Wegovy is administered at a higher dose of semaglutide than Ozempic. Wegovy’s clinical trials showed more weight loss but only slightly greater improvements in glycemic control compared to Ozempic, Chao says.
The FDA sees Ozempic and Wegovy as two different medications for different uses. Chao says many insurance companies cover Ozempic for diabetes but don’t cover Wegovy for obesity—a prime example of weight bias in health care. That’s why some medical providers use the two doses somewhat interchangeably, as obesity and type 2 diabetes are inextricably linked–obesity is the leading risk factor for developing type 2 diabetes.
What are the risks?
Like every medication, there can be downsides.
The most common side effects are gastrointestinal issues, such as nausea, constipation, and diarrhea, Chao says—and more rarely, pancreatitis, gallbladder disease, and diabetic retinopathy.
Angela Godwin, nurse practitioner and clinical assistant professor at the NYU Rory Meyers College of Nursing, explains that recent reports of extreme vomiting and gastroparesis (delayed emptying of the stomach) are to be expected.
Gastroparesis “just means the food’s in your stomach longer, which then makes you feel fuller longer,” she explains.
Nausea is one of the biggest side effects of medications like Ozempic and Wegovy, and that can always lead to vomiting, Godwin says. In June, the American Society of Anesthesiologists recommended patients stop taking these medications before surgery to avoid aspiration and vomiting.
“Normally, in my experience, it’s tolerable,” she says. “But then there are times when I ask [patients], ‘Well, what happened?’ And they [say] they ate too much and ate too quickly. And then yes, the body will vomit it up, because it just can’t tolerate that much food anymore.”
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Continuing research is helping us understand more about what happens when people stop taking these medications—which many may be forced to do amid current shortages. Research does suggest that stopping use of this medication could cause patients to regain weight, especially if they didn’t make any lifestyle changes.
“In almost all weight-loss studies, it really depends on your foundation,” says Stanford endocrinologist Sun Kim. “Your efforts at lifestyle will determine how much weight you lose. If you have your foundations like food, exercise, and sleep, you’re gonna do well.” If not, you might regain as much as 20 percent of the weight lost per year.
These medications can also be incredibly expensive, especially without insurance. Kim says an injection pen can run more than $1,000.
What does it mean to use this drug off-label?
Using a drug off-label means using it in a way other than its intended and its FDA-approved purpose, which may not be safe or effective. Ozempic has been approved only for type 2 diabetics, and Wegovy has been approved only for patients with a BMI above 30, or 27 if they have a weight-related comorbidity like high blood pressure.
“There is no scientific evidence to show whether this medication will be effective or of benefit to those who do not fit the criteria from the FDA-approved label indications, such as people with a BMI lower than 27,” Chao says. “We also do not know the side effects or risks in these populations—there could be unknown drug reactions. These medications are not meant to be a quick fix.”
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Even if you meet the criteria, experts warn against trying to obtain the medication without a prescription by traveling to countries that don’t require them.
“When the medication’s not used under supervision of a health-care provider, then they can come into misuse,” Chao says. “There could be more serious adverse events that can happen.”
Godwin says recent reports of extreme vomiting and gastroparesis are a reminder that patients should schedule regular checkups with their doctor when taking these medications.
“I think it’s so popular now that practitioners might be tempted to just prescribe more freely, and then maybe not monitor patients as frequently,” she says.
Patients should not increase their Ozempic dose without doctor approval—which is possible because there are multiple doses in one pen. “They could definitely have a lot of poor side effects, because they didn’t titrate up to that level yet,” Godwin says. The same could be said for Wegovy, which comes in a pack of four one-dose pens.
Robert Gabbay, the American Diabetes Association’s chief scientific and medical officer, said the organization is “very much concerned” about the Ozempic shortage.
“The medication has been an important tool for people with diabetes,” he says. “Not only does it lower blood glucose and weight but it has been shown to decrease cardiovascular events—heart attacks—one of the leading causes of death for those living with diabetes.”
A last resort?
Still, Kim says that prescribing drugs like Ozempic and Wegovy to patients who are desperate for a new approach to weight loss can make her feel “like a superhero.” By the time patients come to her, they’ve often tried methods like Weight Watchers and following the advice of dieticians. In that case, she says, medications like Ozempic and Wegovy can be a great option.
“What I find is sometimes as they’re becoming successful at losing weight, it really does feed into their lifestyle too, and then they’re able to be more active,” Kim says. “It’s hard to lose weight. Seventy-five percent of the U.S. population is overweight or obese. I feel that we shouldn’t be holding this back if this can help.”
Chao agrees that these medications are a good alternative for those who are unable to lose 5 percent of their body weight within about three months of making lifestyle changes. Still, she recommends trying those approaches before turning to medication.
Patients should “make sure that they’re focusing on a healthy dietary pattern, reducing calories, as well as increasing physical activity,” she says. “It’s important they know that even if they are taking the medication, it’s not an easy way out: They’re still going to have to make lifestyle changes.”
Editor’s note: This article has been updated for clarity on the differences between Ozempic and Wegovy.