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Are Anti-Obesity Medications Changing Bariatric Surgery?
M. Sophia Newman, MPH
April 9, 2025
15 MinPrintShare
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Anti-obesity medications (AOMs) are having a powerful impact worldwide.
The glucagon-like peptide-1 (GLP-1) receptor agonist Ozempic (semaglutide) is so popular that the economy of Denmark, where Novo Nordisk produces the drug, now hinges on the drug’s success; nearly one in every five Danish jobs created in 2023 was at the manufacturer.1
Moreover, a 2025 study of more than 215,000 patients who used a GLP-1 drug found an extensive range of unexpected health benefits additional to weight loss, ranging from reduced rates of respiratory failure to a lower risk of developing gangrene to fewer seizures.2 Upheaval in the lives of those taking GLP-1 drugs also appears to extend far beyond health per se, involving shifts in lifestyle choices and romantic relationships.3
In short, there seems to be no end to the wide range of changes AOMs may bring. Indeed, their scope may soon expand further: more than 120 AOMs are now in the pharmaceutical development pipeline, one-third of which work by mechanisms similar to those of existing GLP-1 drugs.4 Because obesity affects approximately 40% of all US adults and 16% of the global population,5 the economic, medical, and cultural impacts of AOM use may prove to be extremely far-reaching.
Amid all this, the question remains: what does this mean for metabolic and bariatric surgery, the other highly effective weight-loss option?
Brief History of AOMs
Although the massive popularity of AOMs is relatively new, these drugs have been available for more than 30 years. In the 1990s, fenfluramine, dexfenfluramine, and phentermine cumulatively reached 2.5 million patients seeking weight-loss options.6 However, after reports of pulmonary hypertension and heart-valve abnormalities, fenfluramine and dexfenfluramine were removed from the market in 1997 and overall AOM use declined.6
Over the next 20 years, the available options proved to be unpopular. This included orlistat, which received US Food and Drug Administration (FDA) approval in 1999 as Xenical and in 2007 as Alli. This lipase inhibitor reduces absorption of fats but is associated with minor weight loss and a side effect of steatorrhea, dimming patient interest. Phentermine-topiramate and bupropion-naltrexone also combined a range of side effects with modest weight loss and had poor patient uptake. Per data from the National Health and Nutrition Examination Survey, just 0.8% of eligible US adults were taking AOMs between 2015–2018.7
It wasn’t until the rise in the off-label use of diabetes drugs liraglutide (brand-named Saxenda; approved as an AOM in 2014), semaglutide (approved in 2017 as Wegovy and 2022 as Ozempic), and tirzepatide (approved for sale as Mounjaro and Zepbound, both in 2023), that GLP-1s became a substantial part of treating the obesity epidemic.
“It’s only been recently that medical weight management has been this effective, with up to 20% weight loss with GLP-1 use,” explained Luke Funk, MD, MPH, FACS, a bariatric surgeon at the University of Wisconsin-Madison.
Public interest has increased so swiftly that patients, including those using AOMs to treat diabetes or heart disease, have struggled with supply shortages and other access issues. As of mid-2024, approximately 22% of those who are overweight or obese were taking a GLP-1 drug.8 Of those, 40% were taking these drugs primarily to lose weight8—or 11 times as many as who took weight-loss medications 2015–2018.7 As options increase and prices potentially decrease, that number is expected to rise.
Table. Current US Food and Drug Administration-Approved Drugs for Weight Loss
Bariatric Surgery or AOMs?
In the 2010s, bariatric surgery was used by approximately 0.5% of the eligible US population,7 and this value has risen to less than 1% of all eligible US patients in more recent years.9 This statistic is true despite a growing range of options for weight-loss surgery, including myriad endoscopic and laparoscopic approaches.
This lack of patient interest persists even though bariatric surgery has unquestionably better results than AOMs. Marina S. Kurian, MD, FACS, who practices bariatric and metabolic surgery as a clinical professor of surgery at NYU Langone Health in New York City, explained, “People talk about how these medications have decreased risk of major adverse cardiovascular events by 20%. That’s great. Worldwide, that’s going to make a huge difference in cardiac death. But surgery reduces it by 40%.”
As striking as that statement is, Dr. Kurian may be understating the case. For example, in a cohort of Israeli patients with diabetes who received either bariatric surgery or GLP-1 drugs, those who underwent surgery had 62% lower mortality risk than those who received a drug regimen (hazard ratio, 0.38 [95% CI, 0.25-0.58]).10
In addition to its lifesaving effects, the primary goal of weight loss is met more effectively with surgery. Bariatric procedures typically offer both a greater percentage of total weight loss and longer-lasting weight loss than AOMs do.11
Additionally, surgery appears to be more cost-effective than AOMs for weight loss. An abstract12 presented at Clinical Congress 2024 assessed relative costs and quality-of-life outcomes and found that, because AOMs required ongoing expenses over the long term (calculated at $11,628 annually), they were less cost-effective than the higher one-time cost of weight-loss surgery (estimated at $18,581). This held true until the cost of AOMs dropped to $568 per month or less—significantly lower than the current price.
Given these facts, why has bariatric surgery remained relatively unpopular?
Dr. Kurian described the problem as multifaceted. It includes widespread stigma against obesity and patients’ misplaced sense of personal responsibility: “Getting patients to recognize that they don’t have a disease of willpower, that it’s not their shame—all those things will go further to get them to say, ‘Hey, I need to have surgery.’”
In addition, both Drs. Kurian and Funk described complex barriers in insurance coverage and care access for a procedure that can have high upfront costs. Dr. Funk has led a research team that has examined this question for several years via qualitative methods; they found a mix of administrative and logistical barriers, particularly a failure of insurance to cover bariatric procedures.
“We have to fight for insurance coverage and also even anti-obesity medication coverage,” Dr. Kurian said of the experience at her own institution.
She noted a current misunderstanding of how definitive a cure for obesity and overweight AOMs might be, which, to some, leads to a kind of false dichotomy.
“It’s like saying Lipitor should prevent heart attacks and CABG [coronary artery bypass grafting surgery], right?” Dr. Kurian said. “But it doesn’t. Severe heart disease doesn’t go on medication. It gets bypassed. Severe heart disease needs to be treated with surgery. But we understand that these patients may also need medications long term to keep the disease at bay. You don’t just get a heart stent and a CABG; then there’s a continuum, where we need more than one thing in our armamentarium to treat the patients appropriately.”
AOMs as Gateway to Comprehensive Care
Both AOMs and bariatric surgery are indisputably relevant to the same patient population. Indeed, the ACS Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) permits metabolic and bariatric surgery centers with a Comprehensive Center designation to incorporate AOMs into their practice and add obesity medicine qualifications, per the 2022 MBSAQIP standards manual, Optimal Resources for Metabolic and Bariatric Surgery.
“The most effective approach to patient care recognizes that anti-obesity medication and bariatric surgery work best together, rather than in competition, to achieve and sustain significant weight-loss and health improvements,” summarized Lisa Hale, MSN, RN, CNOR, CPHQ, who is the manager of MBSAQIP at the ACS.
A major question, however, is how to combine the two approaches to maximize patient outcomes.
Intriguingly, the cost-effectiveness study7 presented at Clinical Congress 2024 found that combining medication use and weight-loss surgery was the most cost-effective approach, despite the higher overall cost of combining the two approaches. Relative to expense, the combination provided the greatest estimated increase in quality-adjusted life-years.
Thus far, however, insufficient data are available on when and how to best combine AOMs and surgery for weight-loss patients. Studies are not yet conclusive on whether preoperative GLP-1 use results in greater total weight loss than surgery without any AOM use. Dr. Funk noted that the results of the early studies on this question suggest that preoperative AOM use does not increase postsurgical weight loss,11 concord with his clinical experience.
He also noted that “the best prediction tool” used to calculate weight loss—the MBSAQIP Bariatric Surgical Risk/Benefit Calculator—does not yet take preoperative GLP-1 use into account. Studies also are not always clear on when in the patient’s clinical journey key data on weight loss are collected, obscuring current answers to this question.
In addition, Dr. Funk explained that using AOMs prior to surgery can be potentially beneficial even in the absence of an impact on the patient’s ultimate body mass index (BMI). “Generally, if we have a BMI that is exceedingly high, and we have a weight-loss goal for that patient before surgery, GLP-1s are an option for getting them in the range of successful surgery.”
He described using no single cutoff BMI for this approach, as body shape can contribute to clinical assessment, although “a weight over 500 pounds, even in the 400s” commonly requires preoperative weight loss to optimize surgical safety.
For patients with less severe cases of obesity, a GLP-1 prescription can also be an onramp to surgical care—albeit for psychological reasons. “That is the initial gateway for a lot of patients,” said Dr. Funk. “They feel comfortable, they see that weight loss, and they are more willing to engage in evidence-based approaches.”
On this point, Dr. Kurian agreed the rise of GLP-1 has been advantageous. “Now, most of my colleagues around the country are seeing an increase in new consults coming for surgery, which was what we always thought would happen, because this rise in anti-obesity medication use will be bringing people to care, right? That’s critical to making sure that people get appropriate treatment.”
A major question, however, is how to combine the two approaches to maximize patient outcomes.
Implications beyond Bariatric Surgery
Just as patients undergoing bariatric surgery may benefit from weight loss through GLP-1 drugs before an operation, so will some patients who need to undergo other surgical procedures. Dr. Funk noted that some patients requiring ventral or inguinal hernia repair, cholecystectomy, or other operations can require weight loss to undergo surgery safely.
“For surgeons looking for preoperative weight loss from patients, GLP-1s are an effective treatment—placing those patients on a GLP-1 so that the outcomes would be optimized,” he said.
That said, a research abstract from the forthcoming American Association of Plastic Surgeons Annual Meeting suggests that the risk of surgical site infections is increased among patients without diabetes, cardiovascular, and other major diseases who are using GLP-1 medications at the time of surgery.14
Dr. Kurian added that for patients who have already undergone bariatric surgery who need additional, non-bariatric procedures, their postoperative bariatric status can raise questions for other surgeons.
“This is a lifelong follow-up, with things that come up that are very specific that need to be addressed by a bariatric surgeon. If you have a gastric bypass or a traditional duodenal switch, some of that anatomy is different. So, if you have concerns, if you’re not familiar with it, definitely call a bariatric surgeon. Phone a friend, if you will,” she said.
Sea Change?
While AOMs appear to be creating a sea change in how patients who are obese and overweight approach their clinical care, it is less clear how public opinion on these health conditions will shift.
“I don’t know if medications are changing that,” Dr. Funk said. “There’s still a lot of stigma and frankly discrimination against patients with higher BMIs.”
Nor is it clear how long the intense popularity of the GLP-1 drugs may last. Both Drs. Funk and Kurian cited statistics that more than half of all patients prescribed GLP-1 drugs intended for lifelong use cease taking them within 1 year—in which case, they are likely to regain all the weight they lost.
“That’s where we lose them,” Dr. Kurian said, describing some patients’ disillusionment with all clinical weight-loss care after AOMs fail.
Because several of the most popular AOMs were approved for weight-loss use within the past 3 years, long-term follow-up data on the outcomes of ongoing and terminated usage are not yet available.
“What happens at 5 years, 10 years?” Dr. Funk asked. “We don’t know.”
For now, what is clear is that the need for effective care is urgent. Approximately 40% of US adults are categorized as overweight; another 40% have obesity, and half of those have severe obesity. As of 2022, excess weight was estimated to contribute to 500,000 deaths in the US per year.15
In the face of this massive health crisis, nearly 50% of the US adult population, or 130 million people, are now eligible for the first category of drugs that could turn the tide.
While no drug is a miracle cure, bringing evidence-based, potentially lifesaving clinical care into the realm of possibility for millions of people may prove to be an inflection point in medical history—and a watershed moment for metabolic and bariatric surgery as well.
M. Sophia Newman is the Medical Writer and Speechwriter in the ACS Division of Integrated Communications in Chicago, IL.
Stafford RS, Radley DC. National trends in antiobesity medication use. Arch Intern Med. 2003;163(9):1046-1050.
MacEwan J, Kan H, Chiu K, Poon JL, Shinde S, Ahmad NN. Antiobesity medication use among overweight and obese adults in the United States: 2015–2018. Endocr Pract. 2021;27(11):1139-1148.
Liu N, Funk L. Bariatric surgery trends in the U.S.: 1% is the loneliest number. Ann Surg. 2020; 271(2):210–211.
Dicker D, Wolff Sagy Y, Ramot N, et al. Bariatric metabolic surgery vs glucagon-like peptide-1 receptor agonists and mortality. JAMA Netw Open. 2024;7(6):e2415392.
Syn NL, Cummings DE, Wang LZ, et al. Association of metabolic–bariatric surgery with long-term survival in adults with and without diabetes: A one-stage meta-analysis of matched cohort and prospective controlled studies with 174 772 participants. Lancet. 2021;397(10287):1830–1841.
Sanchez JE, Lundberg A, Jones WN, et al. Comparative cost effectiveness analysis of bariatric surgery and GLP 1 receptor agonists for the management of obesity. Abstract presented at Clinical Congress 2024; October 21-24, 2024.
AbuHasan Q, Funk LM, Holl JL, et al. Preoperative glucagon-like peptide-1 receptor agonist utilization and association with bariatric surgery outcomes. Obes Surg. 2025;35(2):556-560.
Lee CC, Yau A, Chroneos R, Johnson TS. Impact of GLP-1 agonist weight loss drugs on surgical wound complications following plastic surgery procedures. Abstract presented at American Association of Plastic Surgeons Annual Meeting; May 25-27, 2025.
Ward ZJ, Willett WC, Hu FB, Pacheco LS, Long MW, Gortmaker SL. Excess mortality associated with elevated body weight in the USA by state and demographic subgroup: A modelling study. eClinicalMedicine. 2022;48: 101429.
