From utilization to mortality assumptions, these medications raise new cost and risk considerations for actuaries and insurers.
By Kimberly Ferrero
GLP-1 medications (Glucagon-like peptide-1 receptor agonists) did not begin their clinical lives as weight-loss drugs. Instead, they emerged from efforts in the early 2000s to improve treatment options for people with type 2 diabetes. Researchers focused on GLP-1, a naturally occurring hormone released in the gut after eating, because of its ability to stimulate insulin secretion in a glucose-dependent manner and suppress excess glucagon. These properties made it an attractive target for improving glycemic control while reducing the risk of hypoglycemia.
The first GLP-1 receptor agonist, exenatide (Byetta), received U.S. Food and Drug Administration approval in 2005, marking a novel approach to diabetes management. Over time, newer agents improved both convenience and effectiveness. Liraglutide (Victoza) followed in 2010 with once-daily dosing, while semaglutide (Ozempic), approved in 2017, introduced once-weekly administration. More recently, tirzepatide (Mounjaro), approved in 2022, expanded the therapeutic concept further by combining GLP-1 activity with glucose-dependent insulinotropic polypeptide (GIP) receptor agonism.
As these drugs entered wider clinical use, it became clear that their impact extended well beyond blood sugar control—raising early questions for actuaries about how the therapies might affect long-term health risk and insurance costs. Weight loss, initially viewed as a secondary benefit, proved to be a substantial and consistent effect of GLP-1 usage across multiple clinical trials. This observation ultimately led to the approval of higher-dose formulations of liraglutide (Saxenda) and semaglutide (Wegovy) specifically for sustained weight management, formally repositioning GLP-1 medications as obesity treatments rather than solely diabetes medications.
For actuaries, that shift matters more because obesity is a major driver of long-term health costs and mortality risk across insured populations. As these medications move from diabetes care into large-scale weight management, actuaries and insurers are beginning to evaluate how their expanded use can influence health care utilization, insurance pricing, and long-term population health outcomes.
How GLP-1 Medications Contribute to Weight Loss
GLP-1 medications work by amplifying the effects of the body’s own GLP-1 hormone, which plays a central role in regulating appetite, digestion, and glucose metabolism. After we eat, GLP-1 (made in our intestines) helps signal fullness, slows the rate at which food leaves the stomach, and coordinates insulin and glucagon release to keep blood sugar levels in check. Pharmacologic GLP-1 receptor agonists are designed to mimic these effects of the body’s own GLP-1 but remain active in the body far longer than the naturally occurring hormone. Recent analysis by the American Academy of Actuaries suggested that the high cost of these medications, combined with the need for long-term use, could place upward pressure on 2025 health insurance premiums, particularly as more patients met clinical criteria for covered diagnoses.
Several mechanisms appear to work together to produce clinically significant and sustained weight loss. First, GLP-1 medications act on the appetite-regulating centers in the brain, reducing hunger and increasing feelings of satiety. Patients often report eating less, not because of conscious restraint, but because they feel full sooner and for longer periods. Second, by slowing gastric emptying, these medications prolong post-meal fullness and dampen spikes in blood glucose. Third, they enhance insulin secretion and suppress glucagon release in a glucose-dependent way, improving metabolic efficiency without substantially increasing hypoglycemia risk.
Taken together, these effects help explain why GLP-1 drugs have produced more durable weight loss than many earlier pharmacologic approaches, which often relied on stimulant-based appetite suppression or had limited tolerability. What remains most novel about GLP-1 medications is that they target underlying biological drivers of energy intake and metabolic regulation—factors closely tied to chronic disease risk—rather than simply promoting short-term weight reduction, and may, in the long run, contribute to lower health insurance costs by treating related comorbidities, even as they may impact patient longevity and, thus, how life insurance treats these drugs.
Entrance onto the Insurance Landscape
Interest in GLP-1 medications has grown rapidly, not only because of how the drugs work, but also because of the scale of the problem they target. Obesity affects an estimated 42% of U.S. adults, based on nationally representative data from 2017–2020, and is associated with approximately $173 billion in annual medical costs, driven largely by increased rates of cardiovascular disease, diabetes, and related chronic conditions. Against that backdrop, the magnitude of weight loss observed in GLP-1 clinical trials stands out as historically atypical for pharmacologic obesity treatments.
In randomized controlled trials, semaglutide has produced average weight loss of approximately 15% of baseline body weight, while tirzepatide has delivered reductions exceeding 20% in some study populations. A meaningful share of participants achieved weight-loss levels previously associated primarily with bariatric surgery. Beyond weight reduction alone, these trials have also shown improvements across a range of cardiometabolic markers, including blood pressure, lipid profiles, glycemic control, and inflammatory measures. More recent outcomes data suggests potential reductions in major adverse cardiovascular events among high-risk populations, further broadening interest in the downstream health implications of sustained GLP-1 drug use.
For actuaries, these findings raise a critical question: whether clinical benefits will translate into durable improvements in population health and, ultimately, measurable changes in health care utilization and mortality. That question becomes more complex once clinical trial results give way to real-world prescribing patterns, heterogeneous adherence, and uneven insurance coverage. Preliminary real-world data from Milliman suggests that while increased GLP-1 adherence may lower the medical cost of care for certain chronic conditions, these offsets do not yet fully recover the high cost of the medications themselves. As GLP-1 drug use expands beyond controlled trial settings and into employer-sponsored plans, Medicaid programs, and state-regulated markets, attention increasingly shifts from efficacy to access—how many patients receive these therapies, under what conditions, and at what cost? This challenge is further compounded by the shifting landscape of pharmacy spending; in early 2025, a small group of GLP-1 medications accounted for approximately 21% of total prescription costs for large pharmacy coalitions, a massive jump from just 1% in 2020.
To better understand how the emerging evidence is shaping actuarial thinking, we interviewed a panel of health and life actuaries about prescribing trends, coverage decisions, and signals they are watching across markets. Their perspectives illustrate how GLP-1 medications are raising new questions about cost, utilization, and long-term risk for insurers and policymakers.
The Rapid Expansion of GLP-1 Prescribing
GLP-1 prescribing has expanded rapidly, reflecting its expansion from a niche diabetes therapy to a widely utilized metabolic treatment. Recent survey data suggest that between 6 and 12% of U.S. adults are currently using a GLP-1 agonist, while roughly 1 in 8 reports having used one at some point. Claims-based estimates also indicate that prescription prevalence increased sharply from less than 1% of adults in 2019 to about 4 percent by 2024, representing several-fold growth in just five years. Among adults diagnosed with type 2 diabetes, historically the primary prescribing indication, GLP-1 medication use reached 26.5% in 2024. This is equivalent to nearly 7 million people, underscoring how quickly the GLP-1 agonist drug class has become integrated into standard metabolic care.
Demographic patterns suggest that providers—both medical and insurance—must balance clinical needs and access considerations. Utilization tends to be highest among adults aged 50–64 and among individuals with obesity or cardiometabolic conditions, consistent with risk profiles targeted in clinical guidelines. Gender differences have emerged as well, with women reporting higher usage rates than men, particularly when weight management is the primary indication. Socioeconomic disparities are also emerging in the early data, although insurance coverage and affordability remain key determinants of access.
At the same time, real-world persistence remains a significant actuarial unknown. Claims analyses consistently show substantial discontinuation rates, with approximately 36 to over 50% of patients discontinuing therapy within 12 months, with higher rates among individuals using GLP-1 medications primarily for obesity rather than diabetes. Some estimates suggest discontinuation may reach 50 to 75% within the first year, depending on patient population and cost-sharing exposure. Integrated claims research by Prime Therapeutics found that while one-year persistence for weight-loss-indicated GLP-1s improved to roughly 63% by 2024—likely due to resolving drug shortages—long-term persistence remains a hurdle, with only about 1 in 12 patients remaining on therapy at the three-year mark. These persistence patterns reflect a combination of factors, including side effects, cost barriers, and the chronic nature of obesity treatment, and have important implications for projecting long-term cost offsets and population health outcomes.
For actuaries, these early utilization and discontinuation trends highlight both the scale of the GLP-1 medication adoption and the uncertainty surrounding its long-term financial and health impact. While adoption rates continue to rise rapidly, sustained treatment—and the degree to which it translates into measurable reductions in downstream medical costs—remains a critical area for ongoing study in both the health and life arenas.
Early Signals and Limits in Health Actuaries’ Data
GLP-1 medications pose a familiar yet unusually complex challenge for health actuaries: a high-cost innovation with promising long-term clinical benefits, but limited actuarial credibility in the near term. Unlike traditional medical trend drivers, such as hospital price increases or incremental pharmaceutical innovations, GLP-1 agonists combine rapid uptake, significant per-patient costs, and uncertain long-term offsets. Actuaries are closely monitoring early claims data knowing that it only offers a partial picture of eventual impact.
Ben Rayburn, a senior principal actuary at Mercer and chairperson of the Academy’s Health Practice Council’s Active Benefits Committee, works extensively with employer-sponsored health plans and explained that the employer perspective is largely shaped by time horizon. “In the health space, every year is a new decision,” he said. While GLP-1 therapies may reduce long-term risks of cardiovascular disease, diabetes complications, and disability, those benefits often accrue over decades—well beyond the timeframe relevant to most employer plan sponsors.
Mick Diede, chairperson of the Academy’s Health Practice Council’s Health Care Delivery Committee, added that most health coverage decisions operate on a 12-month cycle. Even if actuaries model longer-term outcomes, annual premiums, contracts, and regulatory requirements often dictate how coverage is evaluated. As a result, GLP-1 medications are currently seen primarily as a cost increase rather than a cost offset in employer-sponsored plans. “To the employer, it’s paternal to give that benefit,” Rayburn said, noting that competitive benchmarking often outweighs actuarially demonstrated return on investment. High employee turnover further limits visibility into long-term effects. “People turn over every five to 10 years,” Rayburn said. “That’s another reason they’re not going to see the long-term effects.”
Diede agreed that, at current prices, the economics are difficult to justify purely on cost savings. “At current U.S. prices, use of GLP-1s for treatment of overweight or obese patients absent other conditions is almost certainly a net cost driver,” he said. “In the short term there is no doubt that this is a cost increase.” The immediate “cost tsunami” associated with widespread uptake currently dwarfs measurable savings, even if clinical benefits may eventually emerge.
From a claims trend perspective, the impact of GLP-1 adoption is already noticeable. Prescription drug trend rates are diverging significantly between plans that cover GLP-1 therapies and those that do not. “Actuaries have two different trends,” Rayburn explained. “One if your prescription drug includes GLP-1 coverage and one if it doesn’t. The difference can be very meaningful—several percentage points higher for the Rx trend.” In some cases, overall prescription drug trend may jump by as much as 15% when GLP-1 medications are included, making them a dominant contributor to pharmacy cost growth.
At the same time, actuaries face considerable uncertainty in projecting future costs, due in part to evolving utilization patterns and the complex dynamics of pharmaceutical pricing. Pharmacy benefit managers (PBMs) and manufacturers negotiate rebates that depend heavily on formulary positioning and utilization controls. “Manufacturers will give different rebates for different levels of controls,” Rayburn said. Plans that impose stricter eligibility requirements, such as higher body mass index (BMI) thresholds or more restrictive prior authorization, may limit utilization but receive less generous rebates, increasing the net cost per prescription. Conversely, broader access may increase total utilization while lowering net cost per unit. This creates a delicate balance among access, affordability, and overall spending.
Beyond pricing and utilization, Diede highlighted a broader set of uncertainties that actuaries must incorporate into long-term projections. These include potential future price changes, innovations that could improve long-term adherence, and the possibility that scientific understanding of treatment duration may evolve. “There are still open questions about whether these drugs truly need to be taken for life,” he said.
Additional uncertainty comes from the possibility of new therapies or weight-management innovations entering the market, as well as the potential for longer-term side effects that have not yet emerged in real-world populations. Direct-to-consumer availability and alternative access pathways add further complexity. Patients who do not qualify under plan criteria, or whose plans exclude GLP-1 coverage entirely, may obtain medications outside traditional insurance channels, sometimes using manufacturer coupons or compounded formulations. These pathways may reduce insurer spending in the short term while increasing overall population utilization, making actuarial forecasts of future demand more complicated.
Despite the rapid adoption and growing claims experience, actuaries remain cautious about drawing conclusions from early data. “We don’t see any medical savings yet because of the short-time horizon,” Rayburn said. This reflects both the relatively recent introduction of GLP-1 medications for obesity treatment and the time required for weight loss to translate into reduced incidence of chronic disease complications.
Diede echoed this view. “No,” he said when asked whether meaningful cost offsets are visible yet. “The short-term cost tsunami easily dwarfs any savings,” adding that attributing improvements to a specific therapy is inherently difficult outside controlled clinical trials. Consulting actuaries in particular must balance long-term uncertainty with immediate forecasting needs.
Rayburn described a planning process that relies heavily on ongoing dialogue with PBMs and carriers. “We inquire the heck out of things,” he said, referring to efforts to understand drivers of utilization, pricing changes, and projected trend. This collaboration helps reduce the risk of unexpected cost increases and allows actuaries to incorporate emerging experience into short-term projections.
Coverage decisions themselves also reflect a complex set of institutional dynamics. Diede said public discussions sometimes overplay the role of insurers in determining access to GLP-1 medications. In reality, he explained, coverage policies are often shaped by other stakeholders. “Coverage decisions are largely driven by the federal government for Medicare, state governments for Medicaid, and the ACA individual market, and plan sponsors for self-funded commercial groups,” he said. Health insurers therefore have relatively limited discretion in many segments of the market.
Where plans can exercise influence—particularly in commercial coverage—they often focus on how GLP-1 medications fit within a broader set of weight-management interventions, including lifestyle counseling, dietary programs, and bariatric surgery. These decisions frequently manifest through step therapy requirements or prior authorization policies, which can become points of friction between patients, physicians, and insurers.
New formulations and pipeline developments may further influence utilization patterns. Oral GLP-1 therapies, for example, lower the barrier to initiation for some patients and may expand the eligible population. At the same time, competition among manufacturers and the eventual introduction of new drug classes, including combination and multi-agonist therapies, may affect both pricing and clinical outcomes. These developments introduce additional uncertainty into actuarial projections, underscoring the importance of continuous monitoring.
Equity and access considerations also remain central. Coverage varies widely across commercial plans, Medicaid programs, and other payers, creating disparities in access. “Equity is probably going to become more of a challenge,” Rayburn observed, noting that coverage decisions differ across states and employer plans. Individuals without insurance coverage may still obtain GLP-1 medications through direct-purchase channels, but cost remains a barrier for many.
Ultimately, health actuaries are navigating a transitional landscape in which utilization is expanding rapidly, costs are rising, and long-term benefits remain largely unobserved in real-world data. While clinical evidence suggests substantial potential for improving population health, actuarial modeling must contend with limited historical experience, evolving prescribing patterns, and complex behavioral and economic factors.
For now, GLP-1 medications represent a clear near-term cost driver for health plans, accompanied by the possibility—but not yet the actuarial certainty—of long-term cost savings. As Rayburn summarized, coverage decisions today are driven less by demonstrated financial return than by strategic considerations and competitive positioning. “GLP-1s are very benefit-oriented—people want them, and competitors are offering them—but we don’t yet have enough data to substantiate long-term savings.”
Life Insurance and Mortality Implications
While health actuaries are grappling with the immediate cost implications of GLP-1 medications, life actuaries are focused on a different question: whether the drugs will ultimately translate into measurable improvements in mortality. From a life insurance standpoint, the key issue is whether weight loss and metabolic improvements translate into sustained reductions in long-term mortality risk.
Kimberly Poulopoulos, head of Mortality Innovation & Transformation and senior vice president at Swiss Re, noted that GLP-1 drugs are unlikely to immediately change actuarial assumptions. “Pricing and reserving assumptions are set holistically,” she said. “GLP-1 drugs are one factor among many, not a standalone driver.” Mortality projections already incorporate general improvement trends reflecting ongoing medical, technological, and societal advances.
Richard Bellomo, actuarial risk manager at Lincoln Financial, described a similar framework for evaluating emerging medical innovations. “As an actuarial risk manager, I look at potential medical advancements such as GLP-1 drugs through a three-question lens,” he said. “Are they clinically effective? Can adoption reach a critical mass? And if those conditions are met, can they move the needle on something actuarially relevant?” While uncertainties remain, Bellomo said the emerging evidence increasingly points toward affirmative answers.
For GLP-1 therapies to materially affect mortality assumptions, both actuaries emphasize that insurers will need clear, long-term evidence that improvements in metabolic health translate into durable reductions in mortality across populations. “Robust evidence of that kind will take years to emerge and confirm,” Poulopoulos said, meaning any adjustments to mortality assumptions would likely occur gradually rather than abruptly. Bellomo likewise noted that long-term real-world outcomes—including adherence, discontinuation rates, and sustained lifestyle changes—will ultimately determine whether the drugs produce meaningful improvements in population-level mortality.
The clinical potential is significant. GLP-1 drugs have demonstrated benefits across a range of obesity-related conditions, including improved glycemic control, cardiovascular outcomes, liver disease, and obstructive sleep apnea. Emerging clinical evidence, including cardiovascular outcome studies such as the SELECT trial, suggests the therapies may reduce major cardiac events. If those benefits prove durable, Bellomo noted that mortality improvements would likely arise primarily through reductions in cardiovascular disease, with smaller contributions from other obesity-related conditions.
For life insurers, the drugs also introduce new underwriting questions. Rapid weight changes associated with starting or stopping GLP-1 treatment challenge traditional risk metrics such as body mass index. “This reinforces the importance of looking beyond a single point-in-time measure,” Poulopoulos said, noting that underwriters increasingly consider broader indicators of metabolic health and weight history rather than current BMI alone.
Bellomo emphasized the importance of capturing both medication use and behavioral commitment to long-term health improvements. “Underwriting practices can evolve to ensure risks remain accurately priced,” he said, adding that assessing historical weight patterns and drug use—along with well-designed disclosure questions—can provide a clearer picture of policyholder health trajectories.
Disclosure and behavioral dynamics may further complicate underwriting. Many insurance applications rely on general medication questions that may not reliably capture GLP-1 use, potentially affecting risk assessment. Meanwhile, treatment persistence and weight regain following discontinuation remain important uncertainties. As Poulopoulos observed, “Behavior, not just biology, will determine long-term mortality outcomes.”
Even if GLP-1 therapies ultimately improve population health, their impact on insured portfolios may be more modest than headline projections suggest. Insured populations typically have lower obesity prevalence than the general public, limiting the scale of potential mortality improvement. Differences in access, treatment persistence, and policyholder behavior, including lapse and re-entry patterns, could also introduce new forms of selection risk. Bellomo noted that these dynamics may affect insurers in multiple ways: Improved health could reduce life insurance claims, while longer lifespans may increase demand for retirement income products such as annuities.
For now, life actuaries are monitoring the emerging evidence closely. As Bellomo put it, “The evidence is approaching the threshold where practical planning should begin in earnest, even as we await data on sustained real-world outcomes.” GLP-1 medications may ultimately become an important driver of cardiometabolic health improvement, but translating clinical promise into measurable mortality experience will take years of real-world data.
What Actuaries Should Watch
If nothing else, the rise of GLP1 medications has made one thing clear: These drugs are neither a panacea nor a passing trend. They represent a lasting shift in cardiometabolic care, with actuarial implications that will unfold over years. They’re also reshaping conversations across health and life insurance, even as many of the long-term answers remain just out of reach. In the near term, they are a clear cost driver; over the long term, their value depends on persistence, clinical durability, and whether real-world outcomes mirror trial results.
Medicare coverage debates will be pivotal. If obesity indications receive broader federal coverage, expect step-changes in utilization, rebate dynamics, and formulary strategy across markets tied to Medicare benchmarks. Conversely, continued limits will sustain uneven access and redirect demand through commercial plans, direct-purchase channels, and compounded alternatives—each with distinct trend implications.
The reframing of obesity as a chronic disease—rather than a lifestyle condition—continues to shape coverage policy, underwriting, and benefit design. This shift supports integration with lifestyle and behavioral interventions, tiered eligibility, and outcomes-based approaches, while putting pressure on legacy policies built solely around BMI. Equity and access remain central. Variation by payer, state, and employer plan design, combined with high discontinuation rates, risks widening health gaps. Actuaries should monitor differential uptake, adherence, and downstream outcomes across demographic and clinical segments to avoid hidden selection effects.
Finally, the long-term public health implications on cardiovascular events, diabetes complications, disability, and mortality are all promising but not yet actuarially credible. Expect gradual, evidence-driven adjustments rather than abrupt assumption changes. Across sectors, actuaries share a common to-do list: track persistence and discontinuation patterns, watch for credible cost offsets, and gauge potential mortality impacts as evidence matures. Progress will require crosssector dialogue among actuaries, clinicians, PBMs, manufacturers, and policymakers to align coverage, clinical practice, and evidence generation—turning therapeutic promise into measurable, equitable value.
Tracking Costs and Coverage
GLP-1 medications are already influencing health plan spending and coverage decisions.
- Near-term cost driver: Prescription drug trend can rise several percentage points for plans that cover GLP-1s.
- Coverage varies: Access differs by federal, state, and employer plan; inequities may emerge.
- Utilization controls matter: Step therapy, prior authorization, and BMI thresholds affect total spend.
- Persistence is key: Roughly 36%–50% of patients discontinue within 12 months, affecting long-term cost projections.
Understanding Uncertainty
Even with strong clinical results, real-world outcomes remain uncertain.
- Limited historical data: Short-term claims experience may not reflect long-term savings.
- Behavior affects outcomes: Adherence, discontinuation, and lifestyle changes shape eventual impact.
- Strategic pressures: Coverage decisions often reflect competitiveness and employee demand rather than immediate ROI.
- Ongoing monitoring: Track utilization, rebates, and formulary adjustments to refine assumptions over time.
Underwriting and Selection Risks
GLP-1 therapies introduce new considerations for underwriting and selection risk.
- Beyond BMI: Consider metabolic health, historical weight, and GLP-1 usage rather than just current BMI.
- Behavioral dynamics: Discontinuation, adherence, and policy lapse patterns influence long-term mortality outcomes.
- Hidden selection risk: Uneven access and persistence may create unexpected portfolio effects.
- Considerations: Update disclosure questions and underwriting practices to better capture policyholder health trajectories.
Mortality Implications
Life actuaries are focused on whether GLP-1 drugs will measurably affect long-term mortality.
- Long-term evidence needed: Durable reductions in mortality will take years to confirm.
- Gradual assumption changes: Adjust mortality assumptions slowly as real-world outcomes emerge.
- Primary impact through cardiometabolic improvements: Most mortality benefit is expected from reductions in cardiovascular disease.
- Portfolio implications: Better health could reduce life insurance claims but increase demand for annuity products.
Kimberly Ferrero, Ph.D., M.Sc., is the Academy’s assistant director of research.
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