The GLP-1 Revolution: Who Should Get Treatment — and Who Will Pay for It?

GLP-1–based medicines have moved from diabetes clinics into the centre of obesity policy almost overnight. For individuals in trials, average weight losses and — for some products and populations — reductions in major cardiovascular events are large enough that dismissing the class as a lifestyle fad is no longer serious. For health systems, that clinical progress creates a different problem: demand is already outrunning affordable, equitable supply. WHO’s latest fact sheet estimates that 1.1 billion people — about one in seven worldwide — were living with obesity in 2024. Even with expanding production, WHO projects that fewer than 10% of those who could benefit from GLP-1 therapies will be reached by 2030. The public-health question is therefore not whether these medicines “work” in selected trial populations. It is who should be offered them first, on what grounds, for how long, at whose expense — and how pharmacological treatment fits inside a broader response that still has to reshape food environments, support physical activity and prevent obesity in the first place.

Obesity as chronic disease — and why that changes the payment question

WHO now frames obesity as a chronic, relapsing disease that needs lifelong care, not a short course of willpower. That framing is clinically coherent: when treatment stops after substantial weight loss, much of the benefit erodes. In STEP 4, adults who continued weekly semaglutide 2.4 mg after a 20-week run-in lost a further 7.9% body weight to week 68, while those switched to placebo regained 6.9%. In the STEP 1 extension, participants regained on average about two-thirds of prior weight loss within a year of stopping treatment and lifestyle support. SURMOUNT-MAINTAIN, published in 2026 and funded by Eli Lilly, extends the same lesson for tirzepatide: after an open-label weight-loss phase, adults randomised to continue the maximum tolerated dose maintained a modelled −21.9% change from baseline at week 112, versus −16.6% with dose reduction to 5 mg and −9.9% after switching to placebo — with rescue tirzepatide permitted under the protocol for substantial regain, so the week-112 comparison should not be read as uninterrupted placebo-only treatment for every participant. These are not moral failures; they are biological and behavioural realities of a chronic condition — and they imply recurring, not one-off, system costs.

For payers, that chronicity is where the budget question really bites. A medicine that works while taken is a recurring cost — potentially for years — not a one-off cure. That is precisely why WHO’s recommendation is conditional: efficacy is evident, but long-term safety and maintenance evidence, current prices, health-system preparedness and equity effects remain incomplete. Treating obesity pharmacologically without planning for duration, monitoring and exit strategies is how health systems buy short-term headlines and long-term budget shocks.

Not one drug: what the major trials actually show

“GLP-1” is a convenient shorthand that can mislead. WHO’s guideline evaluates two GLP-1 receptor agonists — liraglutide and semaglutide — and one GIP/GLP-1 dual agonist, tirzepatide. Doses, indications, trial populations and outcome sets differ. Semaglutide 2.4 mg for weight management (Wegovy) is not the same product use-case as lower-dose semaglutide for type 2 diabetes. Tirzepatide (Mounjaro) engages an additional incretin pathway. Liraglutide remains more widely registered and often more affordable in some lower-resource settings, with smaller average weight effects in the evidence WHO reviewed.

In STEP 1 — a Novo Nordisk–funded, randomised, placebo-controlled trial — adults with obesity, or overweight with a weight-related comorbidity, and without type 2 diabetes lost a mean 14.9% of body weight at week 68 with once-weekly semaglutide 2.4 mg plus lifestyle intervention, versus 2.4% with placebo (treatment-policy estimand). Gastrointestinal adverse events were common. That is high-quality evidence of average efficacy under trial conditions; it is not a guarantee of the same effect, adherence or safety profile in every real-world clinic.

Semaglutide 2.4 mg: −14.9%. Placebo: −2.4%.

Semaglutide 2.4 mg

−14.9%

Placebo

−2.4%

Source: Wilding et al., N Engl J Med (2021), STEP 1. Bars scaled to 15 percentage points so lengths remain proportional. Industry-funded trial.

SURMOUNT-1, funded by Eli Lilly, reported still larger mean weight reductions with tirzepatide at 72 weeks (efficacy estimand: about −16.0%, −21.4% and −22.5% at 5, 10 and 15 mg versus −2.4% with placebo). In SURMOUNT-5 — also Lilly-funded, open-label — maximum-tolerated tirzepatide was superior to maximum-tolerated semaglutide for weight (−20.2% vs −13.7%) and waist circumference at 72 weeks in adults with obesity without diabetes. Useful for clinical choice; still not a licence to treat every adult with obesity as if outcomes were interchangeable. For cardiovascular hard outcomes the populations diverge. SELECT remains the landmark obesity-without-diabetes trial: in 17,604 adults aged 45+ with preexisting cardiovascular disease and BMI ≥27, weekly semaglutide 2.4 mg reduced the composite of cardiovascular death, nonfatal myocardial infarction or nonfatal stroke (6.5% vs 8.0%; hazard ratio 0.80). SURPASS-CVOT, by contrast, tested tirzepatide against dulaglutide in people with type 2 diabetes and atherosclerotic cardiovascular disease and showed noninferiority for a similar composite (12.2% vs 13.1%; hazard ratio 0.92) without meeting superiority — evidence for a diabetes population, not a SELECT-equivalent obesity-without-diabetes cardiovascular package. SELECT strengthens prioritising people at highest cardiovascular risk; it does not by itself prove the same absolute benefit for every adult meeting a BMI threshold, and it should not be read across to tirzepatide as if the trials answered the same question.

WHO’s conditional recommendation — and the 2026 allocation agenda

In December 2025 WHO issued its first living guideline on GLP-1 therapies for adult obesity. The headline recommendation is careful: these medicines may be used as long-term treatment for adults with obesity (BMI ≥30), excluding pregnant women. Intensive behavioural interventions may be offered alongside. The guideline is explicit that obesity care must sit inside comprehensive chronic programmes — assessment, behavioural support, management of complications — not a prescription-only pathway. Through 2026, WHO has advanced the next implementation priority: expected-health-benefit–based allocation. Following a June 2026 call for experts, WHO’s Expert Group is advising on risk stratification, prognostic tools and criteria that identify who is most likely to benefit when supply and budgets cannot cover everyone who meets a BMI cut-off. Final implementation guidance is planned for early 2027; countries still lack a finished global rulebook of thresholds and safeguards.

That is the right sequence. Clinical efficacy opened the door; scarcity forces prioritisation. A transparent framework based on expected benefit — comorbidities, cardiovascular risk, severity, feasibility and equity — is preferable to first-come-first-served access shaped by private ability to pay. It is also preferable to vague “everyone with BMI ≥30” promises that health systems cannot keep. What remains unfinished is operational: which risk tools, which thresholds, which safeguards against excluding people who already face barriers to care.

Europe: authorisation is not reimbursement

In the EU, EMA has authorised Wegovy (semaglutide) and Mounjaro (tirzepatide) as adjuncts to diet and physical activity for adults with BMI ≥30, or BMI 27 to <30 with at least one weight-related comorbidity. The marketing authorisation is broad. National payers are narrowing it. France’s Haute Autorité de Santé, for example, has issued a favourable reimbursement opinion for Wegovy mainly in adults with BMI ≥35 after failure of well-conducted nutritional management, and unfavourable opinions for other EMA-authorised situations. Similar prioritisation debates now cover tirzepatide. Obesity-specific cardiovascular outcome evidence remains more mature for semaglutide (SELECT) than for tirzepatide, whose published cardiovascular outcome trial (SURPASS-CVOT) enrolled people with type 2 diabetes. Other countries have delayed, restricted or rejected broad obesity funding. The European pattern is fragmentation: a shared marketing authorisation, divergent willingness to pay.

That divergence matters for equitable access inside Europe as well as globally. If access tracks private insurance, out-of-pocket wealth or the loudest online demand, pharmacological obesity care will deepen existing gradients — including the educational and socioeconomic inequalities already documented in adult obesity across the WHO European Region, where the 2022 regional report estimated that 59% of adults lived with overweight or obesity and 23% with obesity (age-standardised estimates based on 2016 data). Expanding treatment without prioritisation rules risks serving those easiest to reach rather than those with the largest expected health gain.

Capacity, supply and what medicines cannot replace

WHO is clear that chronic obesity care needs trained teams, referral pathways, procurement, monitoring and financial coverage — not vials alone. Gastrointestinal tolerability, dose escalation, contraception counselling where relevant, and follow-up for nutritional status all require organised clinic capacity. EMA’s Executive Steering Group on Shortages has documented EU-wide shortages of several GLP-1 receptor agonists since 2022, driven by demand and manufacturing constraints, and has warned that excessive off-label use for cosmetic weight loss worsens availability for authorised diabetes and weight-management indications — with supply improving through 2025 but still under monitoring. A serious European policy response has to protect indicated clinical use, invest in multidisciplinary capacity, and refuse the false choice between medication and prevention.

Effective pharmacotherapy for those with high expected benefit can coexist with — and may even depend on — healthier food environments, physical-activity infrastructure and early prevention. Medicines treat disease in individuals; they do not redesign the commercial and structural drivers that keep population BMI rising. The practical test is whether governments fund both: targeted, evidence-based treatment for people living with obesity who stand to gain most, and population measures that reduce future incidence. Framing one as the enemy of the other is a political convenience, not a public-health strategy.

What remains uncertain

Long-term real-world safety beyond trial horizons, optimal duration, adaptive dose-reduction strategies after SURMOUNT-MAINTAIN, cost-effectiveness across income settings, and a completed obesity-without-diabetes cardiovascular outcome trial for tirzepatide are still evolving. Industry funding of the pivotal STEP, SELECT, SURMOUNT and SURPASS programmes does not invalidate their randomised designs, but it does require transparent reporting and independent scrutiny of endpoints, estimands and generalisability. Absolute benefits will be smaller in lower-risk populations than in SELECT’s high-risk cohort. Equity cuts both ways: wider access could reduce obesity-related harm where need is greatest, or widen gaps if allocation follows purchasing power.

A fairer test than the miracle narrative

The honest public-health position is dual. These medicines can deliver clinically meaningful weight and, for defined high-risk groups, cardiovascular benefit — evidence strong enough that health systems should plan for them rather than pretend the class is optional fashion. And because benefit is heterogeneous, treatment is often long-term, and global reach may stay under one in ten of those who could benefit through 2030, access must be rationed by expected health gain, not by marketing or wealth. Europe’s task is to align EMA-authorised options with transparent national prioritisation, protect diabetes supply chains, fund the behavioural and primary-care scaffolding WHO insists on, and keep prevention of obesogenic environments on the same agenda. That is less tidy than a miracle-drug story. It is closer to what the evidence, and fairness, can support.

Sources & further reading

1. WHO — Global guideline on GLP-1 medicines for treating obesity (1 December 2025)
2. WHO — Living guideline on GLP-1 therapies for obesity in adults (MAGICApp)
3. WHO — Expert Group on expected-health-benefit-based allocation of GLP-1 therapies (2026)
4. WHO — Obesity and overweight fact sheet (2024 burden estimates)
5. WHO/Europe — European Regional Obesity Report 2022
6. Wilding et al. — Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1), NEJM 2021
7. Lincoff et al. — Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT), NEJM 2023
8. Jastreboff et al. — Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1), NEJM 2022
9. Aronne et al. — Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5), NEJM 2025
10. Horn et al. — Tirzepatide for maintenance of bodyweight reduction (SURMOUNT-MAINTAIN), Lancet 2026
11. Nicholls et al. — Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes (SURPASS-CVOT), NEJM 2025
12. Rubino et al. — STEP 4 weight-loss maintenance after semaglutide, JAMA 2021
13. Wilding et al. — STEP 1 extension: weight regain after semaglutide withdrawal, Diabetes Obes Metab 2022
14. EMA — Wegovy (semaglutide) EPAR
15. EMA — Mounjaro (tirzepatide) EPAR
16. EMA/HMA — EU actions to tackle shortages of GLP-1 receptor agonists
17. HAS (France) — Wegovy (semaglutide) reimbursement opinion for obesity