How drugs like Ozempic can help after bariatric surgery

Reviewed by Yael Cooperman, MD, Ro, 

Written by Amelia Willson 

Reviewed by Yael Cooperman, MD, Ro, 

Written by Amelia Willson 

last updated: Jul 31, 2023

5 min read

Weight loss surgery is growing in popularity. Over 250,000 people undergo bariatric surgery each year in the United States. Around 20% to 30% of those people may experience insufficient weight loss or regain weight after bariatric surgery. While lifestyle changes like diet and exercise are helpful, treatment options to manage post-bariatric weight regain have been scarce and often involve another operation. A recent study shows that people who have difficulty losing weight and keeping it off even after bariatric surgery definitely benefit from adding a GLP-1 agonist medication to their regimen. While the study evaluated liraglutide (brand name Saxenda), semaglutide, available under the brand names Ozempic and Wegovy may hold promise for these patients too. 

If you’ve had bariatric surgery, are worried about weight regain down the road, and wonder if you can use medications like Ozempic after bariatric surgery, here’s the good news: Recent research suggests that using semaglutide after bariatric surgery can effectively reduce weight regain and support long-term weight loss. 

What is Semaglutide? 

Semaglutide is the active ingredient in drugs like Ozempic and Wegovy. It was originally released under the brand name Ozempic for the treatment of type 2 diabetes, in combination with diet and exercise. The medication comes in a prescription pen which you inject on a weekly basis into the skin of your upper arm, thigh, or abdomen. As a GLP-1 drug, semaglutide mimics glucagon-like peptide 1, a hormone that tells your pancreas to release more insulin after you eat. This helps people with type 2 diabetes keep their blood sugar levels in check. 

Semaglutide also delays gastric emptying and prevents the release of more glucagon into your bloodstream. These effects prevent further blood sugar spikes, another benefit for people with type 2 diabetes. But, they also lead people to feel full sooner. Soon, drug makers and scientific researchers realized that many people taking Ozempic were losing weight. This led Novo Nordisk, the manufacturer of Ozempic, to seek FDA approval for semaglutide as a weight loss drug, under the brand name Wegovy. Today, both Ozempic and Wegovy may be prescribed for weight loss, although only Wegovy is officially FDA approved for this purpose.  

Ozempic Important Safety Information: Read more about serious warnings and safety info.

Wegovy Important Safety Information: Read more about serious warnings and safety info.

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How much weight can you lose on semaglutide? 

The average person loses nearly 15% of their body weight within a year and a half of weekly injections of 2.4 mg of semaglutide. 

In addition to slowing down digestion and controlling appetite, Ozempic and Wegovy may have other sustained benefits for weight loss, according to one study of almost 200 people with obesity and overweight. Researchers checked in continuously with participants over a period of two years. They found that semaglutide significantly reduced cravings for salty and spicy foods, as well as dairy, and starches. Participants also found it easier to resist the cravings that did arise. This lines up nicely with other research that suggests that semaglutide affects the way your brain reacts and thinks about food, which can lead you to eat less.

Can you use Wegovy or Ozempic after gastric sleeve or gastric bypass? 

While gastric sleeve and gastric bypass are both considered to be relatively safe and effective ways to lose weight, as many as one in three people regain weight after these procedures. GLP-1 medications like Wegovy and Ozempic can help them lose about two-thirds of that weight regain, according to one study. In the study, participants had gained back 15% of their body weight after bariatric surgery. Just six months later, after starting semaglutide, they had lost nearly 9% of their weight.

Another recent study looked at the use of liraglutide (brand name Saxenda) in patients who had undergone bariatric surgery but still had difficulty managing their weight. The study showed that the drug was significantly more effective than a placebo at helping people lose weight. This is particularly important when the alternative is an additional operation with all the risks it can carry.

About one in three people experienced gastrointestinal side effects, which are common to Ozempic and Wegovy, but — also like Ozempic and Wegovy — the side effects were mild and went away as their body got used to the medication. No serious adverse reactions were reported.

Other studies have found similar improvements in weight loss. In one study, participants began semaglutide treatment about a year, give or take, after their bariatric surgery. Similar to the other study, these participants had regained 12% of their body weight since the surgery. Three months after beginning semaglutide treatment, they lost 6% of their weight. After another three months, they had lost 10%. 

Another study compared the effectiveness of Ozempic and Wegovy vs. non-GLP-1 weight loss drugs in reducing post-bariatric weight regain over the period of one year. At three months, six months, and nine months, semaglutide proved to be more effective — and faster — at weight loss than the other weight loss drugs or lifestyle changes. At three months, participants taking semaglutide had lost 4.5% of their body weight, more than twice as much as those taking a non-GLP-1 drug and more than three times as much as those making lifestyle changes alone. These results were consistent regardless of the type of bariatric surgery.

Ozempic vs. Saxenda after bariatric surgery

Wegovy and Ozempic produce more weight loss than other GLP-1 medications as well. One study compared the effects of Wegovy and Ozempic vs. liraglutide, the active ingredient in Saxenda, another GLP-1 drug. Over 200 people participated in the study, about half of whom had had a sleeve gastrectomy. The others had undergone either roux-en-y gastric bypass (RYGB) or adjustable gastric banding. Twelve months after starting treatment, those taking semaglutide had lost nearly 13% of their body weight, compared with less than 9% for those taking liraglutide. In other words, those taking semaglutide were more than twice as likely to have lost at least 10% to 15% of their body weight. Semaglutide produced similar reductions in weight loss, regardless of the type of procedure the person had done, their age, or their sex.

Semaglutide is not safe for everybody, including people with a personal or family history of thyroid cancer. People with a history of pancreatitis, diabetic retinopathy, and kidney or gallbladder problems, may need to use caution when taking Ozempic or Wegovy. Your healthcare provider can advise you on whether Ozempic, Wegovy, or another GLP-1 medication is a good option for you based on your other health conditions and medications.

Saxenda Important Safety Information: Read more about serious warnings and safety info.

Benefits of weight loss 

While diet and exercise are a foundational first step in any weight loss program, for many people with (severe) obesity, surgery, medication, or both are needed to achieve serious weight loss and keep it off. 

There is no magic number when it comes to a “healthy weight,” but weight loss offers significant benefits for people with obesity. In people with overweight and obesity, losing 10% of your body weight or more could help reduce the risk of cancer, improve your quality of life, and even help manage additional health conditions like osteoarthritis and sleep apnea. In addition to helping you lose weight, GLP-1s like semaglutide can improve your physical functioning, while helping to regulate cardiometabolic risk factors like high blood pressure and elevated cholesterol

Similarly, bariatric surgery does much more than help you lose weight. Bariatric surgery has been shown to reduce the risk of stroke or heart attack by 42%. The weight loss from bariatric surgery also relieves obesity-related health conditions, improves cholesterol, and enhances your quality of life.


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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  • Lautenbach, A., Wernecke, M., Huber, T. B., et al. (2022). The Potential of Semaglutide Once-Weekly in Patients Without Type 2 Diabetes with Weight Regain or Insufficient Weight Loss After Bariatric Surgery-a Retrospective Analysis. Obesity Surgery, 32(10), 3280–3288. doi:10.1007/s11695-022-06211-9. Retrieved from

  • Lupoli, R., Lembo, E., Saldalamacchia, G., et al. (2017). Bariatric surgery and long-term nutritional issues. World Journal of Diabetes, 8(11), 464–474. doi:10.4239/wjd.v8.i11.464. Retrieved from

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How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

July 31, 2023

Written by

Amelia Willson

Fact checked by

Yael Cooperman, MD

About the medical reviewer

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.

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