The buzz around Ozempic began a decade ago when a diabetes drug started to show remarkable weight-loss side effects. Today it remains the most talked-about name in the obesity arena, even though the U.S. Food and Drug Administration has not approved it for that purpose.
GLP-1 Drugs: The Core Science
Ozempic, Wegovy, Mounjaro and Zepbound all belong to the GLP-1 class. They imitate a gut hormone that signals fullness, cutting appetite and slowing stomach emptying. Semaglutide, the active ingredient in Ozempic and Wegovy, is a synthetic version of this hormone.
A 2025 RAND report found that 12 % of Americans have used a GLP-1 drug for weight loss, while 14 % are interested in doing so. Women are increasingly looking at semaglutide while breastfeeding, and some people microdose it to save money, though many doctors warn against the practice.
Cost, Access and New Pricing
Both Ozempic and Wegovy carry a list price of about $1,000 per month when insurance does not cover them. In fall 2025 Novo Nordisk announced a steep discount for select doses. The White House also reached a deal to lower the cost, and retailers such as Costco and Sam’s Club are offering the drugs at a discount.
A pill-form of semaglutide is under development and may broaden access once it receives approval.
The Voice of a Patient
Journalist Johann Hari, who lost 42 lbs on 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.” Hari says, “There’s a concern that maybe they’ll have some effect that we just don’t know in the long term.”
In December 2025 the World Health Organization recommended the long-term use of GLP-1 drugs, along with intensive behavioral therapy, for people living with obesity. The recommendation is conditional because of limited data on long-term efficacy and safety.
Safety and Efficacy: The Manufacturer’s Position
Novo Nordisk says it stands behind the safety and efficacy of all its GLP-1 medicines when they are used as indicated and under a licensed health-care professional’s care. The company notes that its 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.
Wegovy vs. Ozempic: Same Ingredient, Different Rules
Both drugs contain semaglutide. Dr. Maria Daniela Hurtado Andrade, an endocrinologist at Mayo Clinic’s Precision Medicine for Obesity program and a consultant for Novo Nordisk, says, “Technically, they are exactly the same.” She adds that insurance companies will not cover Ozempic for the treatment of overweight or obesity.
Ozempic is approved to treat type 2 diabetes, while Wegovy is approved specifically for weight management in people with obesity or those who are overweight and have a complication such as high blood pressure. The dosage differs: Wegovy can reach 2.4 mg weekly, whereas Ozempic tops out at 2 mg.
Novo Nordisk states that Wegovy and Ozempic are not interchangeable.
How Much Weight Do Patients Lose?
Adults with obesity or who were overweight lost an average of 15 % of their body weight after taking Wegovy for one year and four months, according to Novo Nordisk. A 2024 peer-reviewed study funded by the company found that four years after starting semaglutide, patients maintained an average weight loss of 10 %.
Dr. Cecilia Low Wang, an endocrinologist at UCHealth and professor at the University of Colorado School of Medicine, says, “On average, people lose a significant amount of weight. And along with that, other elements of their health then often get better, too.” She notes that obesity is a risk factor for type 2 diabetes, high cholesterol, heart disease, cancer and mental health conditions such as depression and anxiety.
Cardiovascular and Liver Benefits
The FDA approved Wegovy to reduce heart attack and stroke risk. In 2025 it also approved Wegovy to treat metabolic-associated steatohepatitis (MASH), a serious form of liver disease. The company notes that Wegovy’s effect on the body may improve liver inflammation and scarring.
A 2025 study found GLP-1 drugs, including semaglutide, “probably have little or no effect” on a person’s risk of developing obesity-related cancers. Dr. Cho-Han Chiang, a co-author, told NBC News that “I would say GLP-1 (drugs) probably do not increase the risk of cancer.”
Research also suggests GLP-1 drugs may reduce the craving for alcohol, helping people with addiction.
Common and Serious Side Effects
The most common side effects of Ozempic and Wegovy include nausea, stomach pain, diarrhea, constipation and vomiting. The 2025 RAND survey reported that about half of patients taking a GLP-1 drug experienced nausea, and one-third experienced diarrhea.
Wegovy patients may also experience headache, fatigue, upset stomach, dizziness, bloating, belching, gas, stomach flu, heartburn, and runny nose or sore throat, according to Novo Nordisk.
Potential serious side effects include possible thyroid tumors (including cancer), pancreatitis, vision changes, low blood sugar, kidney failure, gallbladder problems and serious allergic reactions. Wegovy patients may also experience an increased heart rate, and depression or thoughts of suicide.
Muscle, Arthritis and Other Concerns
Dr. Low Wang notes that muscle loss is a possible concern. Novo Nordisk says that current data on body composition do not indicate an association of greater lean body mass loss over fat mass loss with semaglutide treatment, and that no safety signal has been found for lean mass loss.
A 2025 advisory published in The American Journal of Clinical Nutrition urges that dietary protein should be a priority to help preserve muscle mass in people taking GLP-1 medications.
Foods recommended while taking Ozempic include fish, eggs, Greek yogurt, cottage cheese, nuts and seeds.
A large study published in Nature Medicine in January 2025 found an 11 % increase in arthritis risk among GLP-1 drug users. The study did not specify which GLP-1 medications were included, but Novo Nordisk said it is reasonable to assume that semaglutide was among them. The company welcomed independent research investigating the safety, efficacy and clinical utility of its products.
Research funded by Novo Nordisk and published in The New England Journal of Medicine in 2024 found that people with knee osteoarthritis treated with semaglutide for 68 weeks had significantly less knee pain than those receiving a placebo. The authors wrote that weight loss resulting from the drug was probably a major contributor.
Semaglutide is not approved in the U.S. for the treatment of knee osteoarthritis.
Gastroparesis and Stomach Issues
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 company’s spokesperson 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. Research published in JAMA in 2023 found that people who take GLP-1 medications may be at an increased risk of severe stomach problems such as gastroparesis.
Eye Health: A New Area of Investigation
A large study of older adults with type 2 diabetes in June 2025 found those who took a GLP-1 drug had a “substantially higher risk” of developing a rare type of age-related macular degeneration (AMD) than people with diabetes who didn’t take the medication. The study followed 139,000 Canadians, at least 66 years old, for three years. 46,000 patients had taken a GLP-1 drug-semaglutide in most cases-for at least six months.
The absolute risk was still low, but the incidence of wet AMD was 0.2 % among GLP-1 users compared to 0.1 % among non-users. The risk was more than three times higher among patients who had been taking a GLP-1 drug the longest.
The paper found an association, not causality. Andrew Mihalache, a co-author, told TODAY.com that “GLP-1 drugs offer important benefits for cardiovascular health, kidney health and weight management, and those benefits remain very significant.” He added that patients who may be at higher risk for wet AMD, such as older adults, should be aware of the possibility of new visual symptoms.
Dr. Brian VanderBeek, an associate professor of ophthalmology at the Hospital of the University of Pennsylvania, wrote in a commentary that “at most one in 1,000 GLP-1 users could progress to wet AMD over unexposed patients.” He noted that if the risk were carried over millions of users, those affected could end up being a sizable group of patients.
The study also indicated that there is no evidence to recommend more frequent eye screening specifically for patients taking GLP-1 drugs. However, people who notice any new changes in their vision while taking these medications should promptly inform their doctor or see an eye care specialist.
Nonarteritic Anterior Ischemic Optic Neuropathy (NAION)
A small study in JAMA Ophthalmology in 2025 focused on eye complications experienced by nine people who took GLP-1 antidiabetic drugs, including semaglutide. Four of the nine patients developed NAION, an optic nerve injury that can cause blindness.
The authors of both papers said they cannot determine if the antidiabetic drugs cause eye complications until large clinical trials are done. The study suggested that the rapid correction of high blood sugar induced by GLP-1 drugs, rather than a toxic effect, could be a possible mechanism for vision loss.
NAION is a very rare eye disease, and it is not an adverse drug reaction listed on the labels for semaglutide in the form of Ozempic, Rybelsus and Wegovy, Novo Nordisk said. Data from clinical trials do not suggest a causal relationship between the drug and NAION.
Novo Nordisk stated that after a thorough evaluation of studies from the University of Southern Denmark and its internal safety assessment, the benefit-risk profile of semaglutide remains unchanged. The company said it takes all reports about adverse events from use of its medicines very seriously.
Dr. Bradley Katz, the lead author of the 2025 study and an ophthalmologist at University of Utah Health, said more studies are needed but “this is an important issue for ophthalmologists as we monitor usage of these drugs.” Patients who experience sudden vision loss should stop taking the drugs and see a doctor immediately, Katz advised.
How Long Should You Stay on Ozempic?
Obesity is a chronic condition that requires chronic 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.
Low Wang says, “It’s likely to be a lifelong medication.” 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.”
McGowan says starting semaglutide is a commitment to stay on it long term. “Someone who’s considering taking a GLP-1 medication like semaglutide must plan to take it indefinitely,” he notes. He worries that discontinuation can lead to weight regain and an extreme recurrence of hunger.
Other doctors say more long-term data is needed before committing patients to this drug for life. Dr. Zhaoping Li, professor of medicine at UCLA, 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.”
Bottom Line
Semaglutide in Wegovy and Ozempic has demonstrated safety and effectiveness in over 30 clinical trials, Novo Nordisk says. The company emphasizes close monitoring by a health-care provider, attention to any problems, and periodic reassessment of whether patients still need the drug. With that approach, the three doctors say they’re comfortable prescribing semaglutide long-term for weight loss for patients eligible for the medication.
The long-term safety of GLP-1 drugs isn’t known for sure, but doctors have long-term experience with this class of medications. So far, there’s no evidence that 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.”
Key Takeaways
- Ozempic and Wegovy, both containing semaglutide, are widely used for weight loss even though they are not FDA-approved for obesity.
- Clinical studies show average weight loss of 15 % after one year and 10 % after four years, with significant health benefits.
- Side effects range from common gastrointestinal symptoms to rare eye and muscle issues; the overall safety profile remains reassuring according to manufacturers and current data.
The conversation around GLP-1 drugs is evolving as more patients use them, more studies are published, and pricing strategies change. For now, the evidence suggests they are effective for weight loss and health improvement, but patients should discuss long-term use, monitoring, and potential risks with their health-care provider.
