Cost-Effectiveness of Obesity Treatments: Glucagon-Like Peptide-1 Receptor Agonists, Endoscopic Sleeve Gastroplasty, and Metabolic/Bariatric Surgery

Abstract

Obesity represents a major global health challenge, requiring interventions that are both effective and economically sustainable. This review examines the cost-effectiveness of commonly discussed treatment options: glucagon-like peptide-1 receptor agonists (GLP-1 RAs), endoscopic sleeve gastroplasty (ESG), and metabolic/bariatric surgery (MBS). We synthesized evidence from published clinical studies and economic analyses, comparing incremental cost-effectiveness ratios (ICERs) and cost per quality-adjusted life year across obesity severity classes, with particular consideration of implications for Korea’s healthcare context. Clinical trial data indicate that GLP-1 RAs can achieve approximately 15–20% weight reduction, but high cost often places ICERs above conventional willingness-to-pay benchmarks. ESG, a less invasive endoscopic procedure, yields around 15% weight loss and has demonstrated favorable cost-effectiveness, particularly in class I obesity. MBS offers the most durable weight loss, generally 25–30%, along with improvements in survival and quality of life. Economic evaluations consistently report MBS as highly cost-effective—and in some cases cost-saving—especially for class II and III obesity. Comparative findings suggest that ESG is generally more economically favorable than GLP-1 RAs in class I obesity, whereas head-to-head comparisons with MBS are limited. At current pricing, GLP-1 RAs rarely meet accepted cost-effectiveness thresholds. MBS is the most cost-effective intervention for moderate-to-severe obesity globally, while ESG is promising in lower body mass index groups. Despite their efficacy, GLP-1 RAs are limited by cost. As ESG is not yet available in Korea and evidence supporting MBS in class I obesity continues to accumulate, reassessment of cost-effectiveness in the Korean context is warranted.

INTRODUCTION

Obesity is a chronic disease and a global public health crisis. The global prevalence of obesity has more than doubled since 1990, now affecting approximately 16% of adults [1]. In South Korea, obesity rates have also risen steadily, from 30.2% in 2012 to 38.4% in 2021, with the prevalence of class III obesity tripling over the past decade [2]. Obesity contributes to numerous comorbidities—including type 2 diabetes, cardiovascular disease, and certain cancers—that impose substantial morbidity, mortality, and economic costs. For instance, in the United States alone, overweight and obesity were associated with $1.72 trillion in total economic burden in 2016 [3].

Confronted with this burden, healthcare systems are increasingly focused not only on the clinical efficacy of obesity treatments but also on their economic value. Standard lifestyle modifications (e.g. diet, exercise, behavioral therapy) often yield modest long-term weight loss, prompting the need for more intensive therapies. Currently, the three major interventions include glucagon-like peptide-1 receptor agonists (GLP-1 RAs), which are injectable agents like semaglutide and tirzepatide (exactly, a dual agonists of glucose-dependent insulinotropic polypeptide [GIP] and GLP-1 receptors) and; endoscopic sleeve gastroplasty (ESG), a minimally invasive endoscopic procedure; and metabolic/bariatric surgery (MBS), including surgical options such as sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB). Each modality differs in invasiveness, cost, and weight-loss efficacy.

To make informed choices about treatments and public policy, cost-effectiveness analysis (CEA) has become an essential tool. This approach relies on two central measures: the quality-adjusted life year (QALY) and the incremental cost-effectiveness ratio (ICER). A QALY captures gains in both the length and quality of life that result from a treatment. The ICER then determines the additional cost of gaining one extra QALY when shifting from a standard intervention to a new one. Together, these metrics enable standardized comparisons across different therapies and diseases, which helps guide how to allocate limited financial resources [4,5,6].

In Korea, economic evaluations of obesity treatments remain limited. MBS was only recently included in the National Health Insurance Service (NHIS) for patients with body mass index (BMI) ≥35 kg/m² or ≥30 kg/m² with comorbidities [7]. There is little domestic research on GLP-1 RAs or ESG, and Korean-specific cost-effectiveness data are scarce. Thus, this review synthesizes global evidence on the cost-effectiveness of GLP-1 RAs, ESG, and MBS and discusses implications for Korean health policy.

COST-EFFECTIVENESS BY TREATMENT OPTIONS

Obesity interventions vary widely in their cost-effectiveness across different populations and healthcare systems. Table 1 summarizes key economic outcomes for three classes of interventions—GLP-1 RAs, ESG, and MBS—based on recent CEAs. Each entry includes the incremental QALYs gained, ICER, and cost-effectiveness status under the relevant willingness-to-pay (WTP) threshold. Population and setting details (e.g., BMI criteria, country, time horizon) are also noted for context.

Table 1. Incremental cost-effectiveness across interventions.

Treatment	Scenario		QALYs gained	ICER per QALY	Cost-effectiveness (Threshold)	Source
GLP-1 RAs (Pharmacotherapy)	Semaglutide 2.4 mg + lifestyle vs. lifestyle alone	BMI ≥30	+0.181	$122,549	Yes (WTP $150,000/QALY)	Kim et al. [3] 2022 (U.S., 30-year model, payer perspective)
		BMI ≥27 with comorbidity	+0.25	$467,676	No (exceeds $100,000/QALY)	Hwang et al. [8] 2025 (U.S., lifetime microsimulation, broad population)
	Tirzepatide + lifestyle vs. lifestyle alone		+0.35	$197,023	No (exceeds $100,000/QALY)
ESG	ESG vs. weekly semaglutide 2.4 mg	BMI 35–39.9 (Class II obesity)	+0.06	−$595,532 (ESG dominant)	Yes (dominant strategy)	Haseeb et al. [9] 2024 (U.S., 5-year model, Markov model)
	ESG + lifestyle vs. lifestyle alone		+1.23	£2,453	Yes (well below £20,000/QALY)	Kelly et al. [10] 2023 (UK, lifetime model, Markov model, NHS perspective)
MBS	Bariatric surgery vs. standard care	BMI ≥30	+3.25	Dominant (cost-saving)	Yes (Dominant strategy)	Walter et al. [11] 2022 (Austria, 20-year model, payer perspective)
	Bariatric surgery vs. non-surgical management	BMI ≥35 or ≥30 with comorbidity	Not reported (QALYs improved)	$674 per QALY	Yes (far below ₩30 million ≈ $25k/QALY)	An et al. [12] 2020 (South Korea, lifetime model, healthcare system)

Data are drawn from published health economic modeling studies cited in the rightmost column.

Summary of ICERs for various obesity treatment strategies—including GLP-1 RAs, ESG, and MBS—across various BMI thresholds. ICERs are calculated relative to control intervention and presented in cost per QALY gained. Lower ICER values indicate greater cost-effectiveness. Thresholds for determining cost-effectiveness vary by study context (e.g., $100,000–150,000/QALY in the U.S.; £20,000/QALY in the U.K.; ₩30 million/QALY in Korea).

QALY = quality-adjusted life year, ICER = incremental cost-effectiveness ratio, GLP-1 RAs = glucagon-like peptide-1 receptor agonists, BMI = body mass index, WTP = willingness-to-pay, ESG = endoscopic sleeve gastroplasty, NHS = National Health Service, MBS = metabolic/bariatric surgery.

1. GLP-1 RAs (semaglutide, tirzepatide)

GLP-1 RAs such as semaglutide (2.4 mg weekly) and tirzepatide (GIP/GLP-1 receptor dual agonists) have demonstrated remarkable efficacy in weight reduction, achieving approximately 15–20% mean body weight loss in representative trials [13,14]. However, their high cost and the need for long-term use pose significant challenges for cost-effectiveness. Most independent analyses indicate that at current prices, these medications are not cost-effective by conventional standards. A U.S. microsimulation model reported semaglutide's ICER at approximately $468,000/QALY and tirzepatide's at ~$197,000/QALY, both well above the $100,000 threshold [8]. According to cost-effectiveness guidelines [4,5], semaglutide would need to drop in price by approximately 80% to become cost-effective, and tirzepatide by around 30% [8]. Birkenfeld et al. [15] further demonstrated tirzepatide’s potential benefits in preventing type 2 diabetes in high-risk individuals, which may improve its value in targeted populations. According to Docimo et al. [16], while GLP-1 receptor agonists offer clinical benefit, their long-term use may surpass the cumulative cost of bariatric surgery unless drug prices are substantially lowered. Although clinically effective, GLP-1 RAs currently offer poor economic value for general use in obesity. These drugs may still be appropriate, however, in certain situations, such as for high-risk patients (e.g., those contraindicated for surgery).

2. ESG

ESG is a minimally invasive endoscopic procedure that induces moderate weight loss (~10–15% of total body weight) with a favorable safety profile. CEAs consistently show ESG to be economically attractive, particularly for patients with class I and II obesity. A U.S. model based on the MERIT trial estimated an ICER of ~$23,400/QALY for ESG compared to lifestyle modification [17], and ESG was found to be cost-saving when the time horizon extended beyond five years. A UK NHS study similarly found ESG’s ICER to remain well below £10,000/QALY across multiple scenarios [10]. Daniel et al. [18] conducted an additional CEA in the U.S. setting using real-world pricing and confirmed that ESG remained highly cost-effective, reinforcing findings from the MERIT trial. Sharaiha et al. [19] also published 5-year outcomes data showing durable weight loss and sustained health improvements, supporting ESG’s long-term value. However, ESG is generally most cost-effective for lower-BMI patients. In patients with class III obesity, its effect is dominated by surgical options such as SG [20]. Although ESG has not yet been introduced in Korea, reviewing these international models will help determine costs and other factors when it is introduced in the future.

3. MBS

MBS remains the most effective and durable treatment for moderate-to-severe obesity. Procedures like SG and RYGB yield long-term weight loss of 25–30%, with frequent remission of type 2 diabetes, hypertension, and other obesity-related conditions. While MBS has high upfront costs, long-term cost savings from reduced chronic disease burden make it consistently cost-effective or even cost-saving in many studies. A Korean model by An et al. [12] projected that bariatric surgery for morbid obesity yielded an ICER of only ~$674 per QALY gained versus non-surgical management—an exceptionally low ICER far below common WTP thresholds. Moreover, in specific subgroups—such as patients with a baseline BMI between 35 and 37.4 kg/m²—surgery was found to be “dominant,” resulting in greater health benefits at lower lifetime cost than non-surgical care. Earlier modeling studies found most ICERs for MBS to be well below conventional thresholds (e.g., under $10,000/QALY in South Korea), with some scenarios demonstrating dominance over non-surgical care [21]. A U.K. economic model found that bariatric surgery in severe obesity had ICERs of approximately £2,000–£4,000/QALY [22]. Similarly, a U.S. study using a diabetes-focused simulation model reported ICERs of $7,000–$12,000/QALY for gastric bypass compared with medical therapy, with improved cost-effectiveness evident in longer time horizons [23]. The American Society of Metabolic and Bariatric Surgery/International Federation for the Surgery of Obesity and Metabolic Disorders have recently supported expanding indications for surgery in Asian populations to BMI ≥27.5 kg/m² with comorbidities, based on ethnic-specific diabetes risk profiles [24]. Sanchez et al. [25] performed a comparative CEA showing that, even when accounting for high procedure costs, bariatric surgery consistently outperforms GLP-1 RAs in long-term cost-effectiveness. A recent lifetime evaluation of SG across different BMI categories, including those with class I obesity, reported an ICER of $4,327/QALY—well below the conventional WTP threshold—demonstrating robust cost-effectiveness even in lower BMI groups [26]. In summary, MBS is both clinically and economically superior in moderate to severe obesity, and increasingly shows cost-effectiveness even in class I obesity with comorbidities.

COMPARATIVE COST-EFFECTIVENESS ACROSS OBESITY CLASSES

Obesity is heterogeneous, and the relative value of treatments can vary by the severity of obesity. Broadly, interventions with greater weight-loss efficacy tend to become more cost-effective as a patient’s baseline BMI and comorbidity burden increase, because the potential health gains (and cost offsets) are larger. This principle is reflected in comparative analyses evaluating GLP-1 RAs, ESG, and surgery across classes I, II, and III obesity. In this review, we follow standard classifications: class I obesity (BMI 30–34.9 kg/m²), class II (35–39.9 kg/m²), and class III (≥40 kg/m²).

Fig. 1 summarizes ICERs of major treatment modalities across obesity classes, based on data from Saumoy et al. [20], Hwang et al. [8], and An et al. [12]. In class I obesity, ESG was highly cost-effective, with an ICER of $4,105 per QALY gained. In contrast, GLP-1 RAs showed ICERs exceeding $500,000 per QALY in class I populations under U.S.-based analyses, making ESG the more economically favorable option in this group [20]. Recent comparative studies have shown that ESG achieves weight loss outcomes comparable to semaglutide [9], and in simulation models, ESG has been shown to be more cost-effective than GLP-1 RAs such as semaglutide in patients with class I obesity [20]. Among individuals with class II obesity, SG emerged as the most cost-effective option, with an ICER around $5,900 per QALY gained [20]. In contrast, GLP-1 RAs such as tirzepatide had ICERs approaching $197,000 per QALY in some models [8], well beyond typical WTP thresholds used in health policy evaluations. In class III obesity, SG demonstrated dominant cost-effectiveness, offering superior outcomes at lower overall costs compared to non-surgical options. ESG was not evaluated in this group due to limited expected efficacy, while GLP-1 RAs remained economically unfavorable [20]. Notably, cost-effectiveness data for SG in Class I obesity and for ESG in Class III obesity were not identified in the published literature. These gaps reflect the absence of robust evidence in these specific subgroups rather than omission due to minimal effect size. In the absence of credible subgroup-specific data, no extrapolation or imputation was performed to avoid introducing unsupported assumptions. Sharaiha et al. [19] observed that for individuals with a BMI above 40 kg/m², ESG produced noticeably smaller weight-loss effects compared with SG, which in turn reduced its relative economic attractiveness in this subgroup. Similar conclusions emerged from later modeling studies, in which ESG was not included in class III obesity analyses due to its anticipated limited benefit [20]. Sanchez et al. [25] also showed, using simulation approaches, that bariatric surgery generally maintains a stronger cost-effectiveness profile than GLP-1 RAs, even when assuming favorable drug efficacy. In the same vein, Docimo et al. [16] reported that GLP-1 RAs would require both major price reductions and very short treatment courses to come close to the economic value achieved by MBS.

Fig. 1. ICERs by obesity class and treatment modality. Data modeled from Saumoy et al. [20], Kelly et al. [10], and additional sources.

ICER = incremental cost-effectiveness ratio, QALY = quality-adjusted life year, BMI = body mass index, WTP = willingness-to-pay, GLP-1 RAs = glucagon-like peptide-1 receptor agonist, ESG = endoscopic sleeve gastroplasty, SG = sleeve gastrectomy.

Fig. 2 presents a cost-effectiveness plane, mapping incremental costs against QALY gains. The black dashed line marks the $100,000/QALY WTP benchmark; points falling below this line indicate comparatively favorable value. SG is consistently located well beneath this threshold, especially in class II and III obesity, underscoring its strong economic performance. ESG for class I obesity appears close to the threshold, suggesting a modest cost advantage, whereas GLP-1 RAs are positioned far above the benchmark in all classes, reflecting reduced economic favorability at current prices [8,12,20].

Fig. 2. Cost-effectiveness of obesity treatments across obesity classes. Data estimated based on reverse-calculated ICER values derived from Saumoy et al. [20].

GLP-1 = glucagon-like peptide-1, ESG = endoscopic sleeve gastroplasty, SG = sleeve gastrectomy, QALY = quality-adjusted life year.

Collectively, these findings support a stratified approach to obesity treatment. MBS represents the most cost-effective strategy for class II and III obesity. ESG may be considered for class I patients who are ineligible for or decline surgery. While GLP-1 RAs show strong clinical efficacy, their cost-effectiveness is substantially limited at current prices.

DISCUSSION

This review underscores the differential cost-effectiveness of major obesity treatments and offers implications for clinical decision-making and Korean health policy. First, MBS remains the most cost-effective option for moderate-to-severe obesity. Its long-term efficacy in weight loss and comorbidity resolution leads to high QALY gains at relatively low ICERs, often under conventional WTP thresholds. Korean data [12] and global analyses [22,23,25,26] consistently support its economic value. The 2019 NHIS decision to cover MBS for patients with BMI ≥35 kg/m² or ≥30 kg/m² with comorbidities [7] is well justified. Moreover, recent international guidelines recommend extending surgical eligibility to patients with BMI ≥30 kg/m² with comorbidities and even ≥27.5 kg/m² in Asian populations with poorly controlled diabetes [24]. As obesity prevalence continues to rise in Korea [2], expanding surgical access—with appropriate risk stratification—may yield substantial public health benefits.

Second, for individuals with class I obesity or those preferring less invasive care, ESG emerges as a compelling alternative. ESG fills a treatment gap between pharmacologic therapy and surgery, particularly for patients who are medically ineligible for or unwilling to undergo MBS. Saumoy et al. [20] reported an ICER of $4,105/QALY for ESG in class I obesity—well below conventional WTP thresholds. Notably, formal recognition of class I obesity as an indication for surgery only emerged in Western guidelines in 2023 [24], and robust comparative cost-effectiveness data between ESG and MBS in this group are still limited, ESG’s minimally invasive nature, favorable safety profile, and sustained effectiveness [10,17,18,19] support its consideration as a clinically and economically balanced option. Beyond the US, ESG adoption is expanding across Europe, the Middle East, Asia, South America, and Australia. In addition to the previously discussed UK data [10], experiences from Australia, Brazil, and France have demonstrated favorable safety profiles, sustained weight loss, and improvement in obesity-related comorbidities, particularly among patients with a BMI of 30–40 kg/m² or with contraindications to surgery [27,28,29]. While formal cost-effectiveness analyses outside the U.S. remain limited, these reports suggest that ESG may offer potential long-term economic benefits through comorbidity improvement and reduced healthcare utilization. Although long-term real-world economic evidence is still lacking, international insights—from global position statements [30,31] to multicenter clinical experiences—indicate that ESG can be a clinically effective and potentially cost-effective treatment option when used in carefully selected patients.

Third, GLP-1 RAs, including semaglutide and tirzepatide, provide excellent clinical efficacy but currently offer limited economic value due to high pricing. U.S. analyses report ICERs of ~$468,000/QALY for semaglutide and ~$197,000/QALY for tirzepatide [8], well above conventional thresholds [16,20]. Even with documented clinical benefits in diabetes prevention [15], these drugs may become cost-effective only under conditions of significant price reductions or short-term use.

From a Korean healthcare system perspective, the current cost of GLP-1 RAs, ranging between approximately ₩9.6 million and ₩12 million annually, presents a significant barrier to cost-effectiveness. Using a reverse calculation [5] approach based on Korea’s commonly cited WTP threshold of ₩30 million per QALY [32], which is derived from nationwide WTP surveys conducted by the National Evidence-based Healthcare Collaborating Agency and widely referenced in cost-effectiveness studies by the Health Insurance Review & Assessment Service. This threshold reflects the average amount Korean adults are willing to pay for one additional QALY—approximately ₩30.5 million—across various health states, and aligns with the World Health Organization recommendation of 1–3 times per-capita GDP as a reasonable cost-effectiveness benchmark [33]. The maximum justifiable annual cost for a treatment providing 0.1–0.15 QALY gain would be ₩3–4.5 million. Thus, to be considered economically viable, the current drug prices would need to be reduced by roughly 65–75%. This estimation aligns with international analyses. For instance, several results [8,20] demonstrated that in the U.S. context, GLP-1 RAs would need to undergo a price reduction of at least 70% to be cost-effective when compared with lifestyle interventions or bariatric surgery.

In summary, MBS remains the most cost-effective treatment option for class II–III obesity, while ESG is a particularly valuable and cost-effective option for patients with class I obesity. Given the recent expansion of surgical indications to include class I obesity, a re-evaluation of the comparative cost-effectiveness of MBS and ESG in this population is warranted. Although GLP-1 RAs, while effective, are economically constrained and should be selectively utilized pending pricing reform. To optimize obesity treatment strategies in Korea, obesity specialists and policymakers must work collaboratively to balance clinical effectiveness, patient preferences, and fiscal sustainability.

LIMITATIONS

This narrative review has several limitations. Most fundamentally, it is constrained by the heterogeneity and historical limitations of the included studies. Several CEAs predate the widespread adoption of newer anti-obesity agents such as semaglutide and tirzepatide, and many employed differing definitions of obesity severity or comparator strategies. As a result, direct comparisons between ESG, GLP-1 RAs, and MBS are often hindered by methodological inconsistencies. Moreover, most existing economic models were developed in Western countries, limiting their transferability to other contexts such as Korea, where healthcare costs and treatment uptake patterns differ. While general limitations of simulation-based models—such as assumptions about long-term drug adherence, weight maintenance, and cost trajectories—remain relevant, future cost-effectiveness studies should prioritize harmonized design, updated pharmacologic comparators, and country-specific parameters to yield more clinically actionable insights.

CONCLUSION

MBS remains the most cost-effective option for treating class II–III obesity and may also benefit select class I patients with comorbidities. ESG offers a cost-effective, less invasive alternative for lower BMI groups. GLP-1 RAs show clinical efficacy but are not economically viable at current prices. To optimize outcomes and resource use, Korea should consider expanding access to surgical and endoscopic options. For pharmacologic therapies, aligning drug prices with the real-world benefits and burdens experienced by patients would help ensure that these treatments offer meaningful value and are accessible to those who need them most.