Ozempic is synonymous with weight loss for many people, even as they can turn to drugs with other brand names that have been tailored to treat obesity.
The blockbuster Type 2 diabetes medication is not approved for weight management, but it comes with weight loss as a famous side-effect.
“Most people have understood Ozempic as kind of a catch-all for the GLP-1 class of medications,” Dr. Christopher McGowan, a gastroenterologist who runs a weight loss clinic in Cary, North Carolina, tells TODAY.com.
GLP-1 drugs — which include Ozempic and its sister drug Wegovy, as well as Mounjaro and Zepbound — mimic at least one hormone produced by the gut to signal fullness, leading to a reduced appetite.
About 12% of Americans have taken one of these popular medications, according to the KFF Health Tracking Poll.
Journalist Johann Hari, who lost 42 pounds with Ozempic, calls the drugs a powerful tool, but also “a mass experiment, carried out on millions of people, and I am one of the guinea pigs.”
“There’s a concern that maybe they’ll have some effect that we just don’t know in the long term,” Hari told TODAY.com, echoing a worry other patients may have.
So is Ozempic safe?
Novo Nordisk, the pharmaceutical company that makes Ozempic and Wegovy, stands behind the safety and efficacy of all its GLP-1 medicines when they’re used as indicated and taken under the care of a licensed health care professional, it says in a statement to TODAY.com.
Here’s what doctors say:
Are Wegovy and Ozempic the same?
Wegovy and Ozempic have the same active ingredient, semaglutide.
“Technically, they are exactly the same,” Dr. Maria Daniela Hurtado Andrade, an endocrinologist at the Mayo Clinic’s Precision Medicine for Obesity program, tells TODAY.com. Hurtado Andrade is a consultant for Novo Nordisk.
But, “practically, insurance companies will not cover Ozempic for the treatment of overweight or obesity,” she clarifies.
Ozempic is approved to treat Type 2 diabetes by the U.S. Food and Drug Administration, while Wegovy is approved specifically for weight management in people with obesity or those who are overweight and have a complication like high blood pressure.
Another difference between the two is the dosage, she notes. Wegovy doses go up higher, up to 2.4 milligrams weekly, versus 2 milligrams maximum for Ozempic.
It’s not unusual for doctors to prescribe Ozempic off-label for weight loss, Hurtado Andrade says. It’s becoming less common as supply issues that made Wegovy hard to find have improved, McGowan adds.
Novo Nordisk says Wegovy and Ozempic are not interchangeable.
What does semaglutide do to the body?
Semaglutide is a synthetic version of a hormone known as GLP-1, which the body releases into the intestine when people eat food, as TODAY.com previously reported.
It signals to the brain that you’ve had a meal, so patients have reduced appetite, and when they do eat, they feel full sooner. The medication also slows down stomach emptying, which may contribute to the feeling of fullness.
Adults with obesity or who were overweight lost 15% of their body weight on average after taking Wegovy for one year and four months, according to Novo Nordisk.
Four years after starting semaglutide, patients maintained an average weight loss of 10% of their body weight, a peer-reviewed 2024 study funded by Novo Nordisk found.
Doctors say the drug’s effects on the body can make people with obesity healthier.
“On average, people lose a significant amount of weight. And along with that, other elements of their health then often get better, too,” Dr. Cecilia Low Wang, endocrinologist at UCHealth and professor at University of Colorado School of Medicine, tells TODAY.com.
Low Wang, who chairs the FDA’s Endocrinologic and Metabolic Drugs Advisory Committee, says she’s expressing her own views, and not speaking on behalf of the panel or the FDA.
Obesity is a risk factor for Type 2 diabetes, high cholesterol, heart disease, cancer and mental health conditions like depression and anxiety, Hurtado Andrade adds.
“Keeping in mind that obesity is at the core of many of these diseases, treating obesity can truly have a cascade effect of clinical benefits,” she notes. “These are life-changing medications.”
The FDA has approved Wegovy to reduce heart attack and stroke risk.
What are the side effects?
The most common side effects of Ozempic and Wegovy include nausea, stomach pain, diarrhea, constipation and vomiting, according to the manufacturer.
Wegovy patients may also commonly experience headache, fatigue, upset stomach, dizziness, feeling bloated, belching, gas, stomach flu, heartburn, and runny nose or sore throat, Novo Nordisk notes.
Potential serious side effects for Ozempic and Wegovy include possible thyroid tumors, including cancer; pancreatitis, vision changes, low blood sugar, kidney failure, gallbladder problems and serious allergic reactions, according to Novo Nordisk.
Wegovy patients may also experience an increased heart rate, and depression or thoughts of suicide, the company says.
Another concern may be muscle loss, Low Wang says.
Currently available data on body composition do not indicate an association of greater lean body mass loss over fat mass loss with semaglutide treatment, Novo Nordisk says. No safety signal been found so far when it comes to lean mass loss with semaglutide, it adds.
In 2023, Novo Nordisk was sued by a woman with Type 2 diabetes who alleged Ozempic was among medications that caused gastroparesis, or stomach paralysis. The case is still active in the U.S. District Court for the Eastern District of Pennsylvania, but there haven’t been any new filings since March 2024.
A spokesperson for the company noted that gastroparesis is a known risk for people with diabetes and that “patient safety is of utmost importance to Novo Nordisk.”
Gastroparesis is not mentioned in the prescribing information for Ozempic or Wegovy, but delayed gastric emptying is mentioned for each drug.
People who take GLP-1 medications may be at an increased risk of severe stomach problems such as gastroparesis, research published in JAMA in 2023 found.
“These adverse events, although rare, must be considered by patients who are contemplating using the drugs for weight loss,” the authors wrote.
How long do you stay on Ozempic for weight loss?
Obesity often requires ongoing treatment, and most people “will have difficulty sustaining weight loss” after stopping the medication, Novo Nordisk says.
Several doctors interviewed by TODAY.com believe semaglutide needs to be taken for years, decades or possibly life.
Obesity is a chronic condition that needs chronic treatment, just like high blood pressure does, Low Wang says.
“It’s likely to be a lifelong medication,” she notes.
“It is a drug that we anticipate will require long-term use,” Hurtado Andrade adds. “We’re putting you on a treatment that is treating the biological basis of the disease, and if you stop that medication, then you’re not going to have that effect, and you’re very likely to regain the weight back.”
Starting semaglutide is a commitment to stay on it long term, McGowan says.
“Someone who’s considering taking a GLP-1 medication like semaglutide must plan to take it indefinitely,” he notes. “The GLP-1 medications are designed to be used in one way and only one way, which is continuously. That means a long-term, essentially lifelong use once you start it.”
McGowan’s biggest concern is that a patient will discontinue their medication, which can lead to weight regain and recurrence of hunger that “can be extreme,” he says.
But other doctors say more long-term data is needed before committing patients to this drug for life.
“I understand there is an argument that obesity is a chronic disease like hypertension, diabetes, and once you need to be on it, you should be on it for lifetime. But I don’t think the data is there for the effectiveness of this class of drug on a long-term basis. There is a potential, but we’re not there,” Dr. Zhaoping Li, professor of medicine and chief of the division of clinical nutrition at the University of California, Los Angeles, tells TODAY.com.
“We need to be vigilant to monitor all our patients carefully. The best use of this class of drug would be leveraging the window of opportunity provided by the drug to help patients to improve lifestyle for longevity and quality of life.”
Is Ozempic safe to take for life?
Semaglutide in Wegovy and Ozempic has demonstrated safety and effectiveness in over 30 clinical trials, Novo Nordisk says.
“Our GLP-1 products have a long history of use in treating Type 2 diabetes (over 19 years) and obesity (almost 10 years), supported by robust clinical data and over 22 million patient years of exposure,” the company notes in a statement.
Novo Nordisk also says it work closely with the FDA to monitor the safety of its medicines.
What about the possibility of a serious problem emerging years or decades down the road?
“We always worry about that. … We’re constantly on the lookout for new side effects,” Low Wang says. “(But) with semaglutide being out for this many years, so far nothing has emerged that’s been really new in terms of safety signals.”
She tells patients that the long-term safety of GLP-1 drugs isn’t known for sure, but doctors do have long-term experience with this class of medications.
So far, there’s no evidence long-term use is harmful, Hurtado Andrade adds.
Millions of patients are now using these medications, so it’s conceivable a rare, previously unidentified side effect may appear, but overall, “the concern is low that something new or unusual will emerge,” McGowan says. “It’s actually a very reassuring safety profile.”
With what’s known now, the three doctors say they’re comfortable prescribing semaglutide long-term for weight loss for a patient eligible for the medication.
With close monitoring by a health care provider, paying attention to any problems and periodically reassessing whether patients still need to be on the drug, “we can do this safely,” Low Wang says.
