Introduction

The global obesity market is entering a new phase. If 2024 was the transition year and 2025 the year of consolidation, 2026 is shaping up to be the year of acceleration. Clinical breakthroughs, shifting policies, and changing market dynamics are converging to redefine obesity care globally. The question is no longer if obesity pharmacotherapy will transform obesity management, but how fast and how far it will go.

The past two years have seen unprecedented momentum: GLP-1 therapies moved from niche to mainstream, supply issues arose then abated, and asset pipelines expanded beyond weight loss to whole-body medications. Recent signals underscore this shift: Eli Lilly became the first pharmaceutical company to surpass a $1 trillion market capitalization ^[1] buoyed by global demand for obesity medications. As we look to 2026, the story becomes one of defining firsts: the debut of oral GLP-1s, the first loss of exclusivity for a GLP-1 receptor antagonist, and landmark coverage decisions such as obesity medications entering Medicare formularies for obesity as a standalone indication. These milestones will redefine how obesity care is delivered, marking a turning point that will shape the market’s trajectory for 2026 and the years to come.

2025 in Review: Solidifying the Era of Obesity Treatment

2025 marked a pivotal moment for obesity care. The year delivered progress across clinical evidence, policy, and changing market dimensions, reinforcing obesity as a chronic disease requiring structured, long-term management.

Clinical Frameworks: Defining Obesity Beyond Body Mass Index (BMI)

An important milestone of 2025 was the publication of The Lancet Diabetes & Endocrinology Commission on the Definition and Diagnostic Criteria of Clinical Obesity. This global initiative reframed obesity as a chronic, systemic disease rather than a mere risk factor. The report highlighted the limitations of BMI, and instead the Commission recommends combining BMI with waist circumference, waist-to-height ratio, and clinical markers of organ dysfunction to diagnose obesity accurately. Yet, the practical impact has been minimal. Most health systems still struggle to capture a single, simplistic metric like BMI, let alone implement more complex diagnostic measurements despite the Lancet Diabetes & Endocrinology Commission’s recommendations. Evidence from German clinical practice in an IQVIA study underscores this gap: BMI documentation was recorded for only 10.8% of patients ^[2] highlighting that comprehensive measurements of obesity are not being translated to clinical practice. Further solidifying 2025 as the year of updates to clinical frameworks, the European Association for the Study of Obesity released a new pharmacotherapy framework ^[3]. The framework prioritised semaglutide and tirzepatide as first-line treatments, based on evidence of ≥15% weight loss and benefits in complications such as cardiovascular disease and sleep apnoea. Similarly, the American Association of Clinical Endocrinology introduced its Adiposity-Based Chronic Disease model, replacing BMI-centric classification with a staging system based on obesity-related complications ^[4]. The guidelines also prioritise obesity medications like semaglutide and tirzepatide for their proven efficacy in preventing major adverse cardiovascular events and improving metabolic health.

Market Dynamics: From Shortages to Price Pressures

After prolonged supply constraints, the FDA officially declared US GLP-1 shortages resolved in April 2025, removing semaglutide and tirzepatide from its shortage list and ending enforcement discretion for compounded versions by May 2025. However, compounders continue to operate, offering personalised versions of these medicines through non-traditional direct-to-consumer channels . The new US Administration‘s broader policy goals to rebalance prices between the US and rest of world brought new challenges in the UK: in September 2025, Eli Lilly implemented a UK-wide list price increase of up to 170% for Mounjaro paid for out-out-pocket, where the UK will be a £2bn+ market by the end of 2025. Eli Lilly’s first nine months of 2025 underscored the scale of the GLP-1 surge: Mounjaro and Zepbound generated $39.5 billion in revenue and surpasses Merck’s Keytruda as the world’s best-selling medicine^[5]. This performance reflects unprecedented demand despite earlier supply constraints and sets the stage for pricing and reimbursement debates as the market matures.

Clinical Evidence: Expanding the Evidence Base

2025 was rich in clinical evidence on obesity medications. The SURMOUNT-5 trial confirmed tirzepatide’s superiority over semaglutide in levels of weight loss ^[6]. Other head-to-head trials added clinical momentum to the obesity space throughout 2025. SURPASS-CVOT meanwhile, provided new evidence on the cardiovascular benefits of tirzepatide, although conducted in a type 2 diabetes population and comparing tirzepatide to dulaglutide ^[7]. Meanwhile, orforglipron demonstrated significant weight loss efficacy ^[8] consistent with injectable GLP-1 medicines. The GLP-1/GIP dual agonist, HRS9531, from Hengrui, reported positive Phase 3 results in weight loss, and is the second (after Innovent) Chinese company to submit marketing authorisation for an obesity asset.

In 2025 we saw label expansions for semaglutide and tirzepatide, underscoring a trend toward whole-body health. Semaglutide gained FDA approval for MASH, as well as FDA and EMA approval in chronic kidney disease. Tirzepatide gained FDA approval for sleep apnoea. Importantly, semglutide’s approval for MASH marks a watershed moment as it is the second ever MASH-specific therapy to be approved, and the first GLP-1 receptor antagonist, giving it momentum to significantly disrupt the MASH treatment market. At the end of 2025 we saw Eli Lilly’s Phase 3 TRIUMPH-4 trial for retatrutide read out. Retatrutide reported up to 28.7% average weight loss and pain reduction of up to 75.8% on the WOMAC scale in adults with obesity and knee osteoarthritis ^[9]. Regulatory submission for retatrutide is expected in 2026. These developments underscore a broader trend where obesity medicines are evolving into whole-body therapies with implications across multiple disease states.

Policy and Global Health

Policy advances in 2025 laid critical groundwork for the next phase of obesity care.

In Global Health policy, the World Health Organisation (WHO) issued its first global guideline on the use of GLP-1 medicines in treating obesity in December 2025. This landmark policy change recognises obesity as a chronic disease and recommends that GLP-1 antagonists are used by adults for the long-term treatment of obesity. These guidelines mark a significant step toward formalising obesity treatment within global health policy. In addition, WHO included GLP-1 therapies on its Essential Medicines List (EML); however, this was for diabetes indications and GLP-1s were not included on the EML for obesity.

Adding to this momentum, the United Nations Fourth High-level Meeting on Non-Communicable Diseases (NCDs) in September 2025 ^[10] marked a major milestone. Heads of State adopted a new Political Declaration under the 2030 Agenda for Sustainable Development - to reduce premature NCD mortality by one-third by 2030. This update elevates obesity within the global noncommunicable disease agenda and sets a clear mandate for action.

At the European level, progress continued with the European Union Cardiovascular Health Plan, which is expected to be published in December 2025, outlining a framework for integrated chronic disease prevention. The European Cardiovascular Health Plan Roadmap from the European Alliance was published earlier in 2025 and calls for comprehensive approaches to incorporate the recognition of obesity as a trigger for cardiovascular disease. Additionally, Members of the European Parliament held their inaugural meeting, signalling political commitment and initiating dialogue on obesity priorities across member states.

Italy became the first country in the world to officially recognise obesity as a chronic, recurring disease through a new law, a landmark step even as reimbursement policies across Europe remain fragmented.

Themes continuing from 2025 into 2026

As the obesity market moves into its acceleration phase, several trends that gained traction in 2025 will continue to influence strategies and market dynamics in 2026:

• As the obesity market evolves, there is a growing recognition that use of obesity medications to maintain weight will be critical for many people. Whilst the current focus remains on induction, themes will begin to shift towards how long-term use can be supported. This includes early thinking around strategies such as dose splitting and micro-dosing, alongside the potential role of oral formulations in making maintenance more practical and affordable.
• In November 2025, the Trump administration announced landmark agreements with Eli Lilly and Novo Nordisk reducing the monthly price of GLP-1 weight-loss drugs from over $1,000 to as low as $245 for eligible patients. Starting in mid-2026, Medicare will begin covering these drugs for select patient groups and state Medicaid programs have the option to adopt similar coverage at these discounted rates. Looking ahead, the influence of US policy and Most Favoured Nation (international reference) pricing will remain a central trend that shaped obesity care in 2025 and will continue to do so into 2026 and beyond.

2026: Acceleration and Market Transformation

The coming year promises rapid evolution across innovation, policy, and market access. Several forces will shape this trajectory:

Patent Expiry and Pricing: Semaglutide’s Loss of Exclusivity

Off-patent semaglutide will be a defining event in 2026 as it begins to come off patent in several countries. This includes large countries such as India, Canada, China, Brazil and Turkey which make up 40% of the world’s population and an estimated 33% of the world’s population of adults living with obesity ^[13]. As generics enter the market, price dynamics will reshape affordability and access. For users this could segway into an expansion of the private market and for payers this could provide an affordable entry point for public reimbursement.

In November 2025 Novo Nordisk filed for submission to the FDA for a higher dose of semaglutide, 7.2mg. Thanks to the FDA’s National Priority Voucher program Novo Nordisk should see the FDA's decision within one to two months, resulting in high dose semaglutide availability in 2026.

The Year of Orals: Convenience Meets Innovation

2026 is set to be the ‘year of the orals’, marking a major inflection point in obesity medication accessibility and patient preference. After a few years of injectable dominance, oral formulations are emerging as a game-changer for adherence and ease of use thanks to their lack of cold-chain requirement, but also a game-changer for their ability to unlock the long-term maintenance opportunity ^[14].

Novo Nordisk will lead first with its oral semaglutide, with regulatory approvals granted by the FDA late December 2025 and full commercial rollout in early 2026. Meanwhile, Eli Lilly is advancing orforglipron, the first small-molecule GLP-1 receptor agonist for obesity. FDA approval is anticipated in 2026, through the FDA's national priority voucher program, positioning Lilly to compete aggressively in the oral segment. Futhermore, 2025 results from the ATTAIN-MAINTAIN trial demonstrated orforglipron’s ability to compete in the maintenance segment. Top-line results showed that on average, people who switched to orforglipron from semaglutide had a superior percent maintenance of body weight reduction, showing that subjects held onto their earlier weight loss compared to those who previously reached a body weight plateau.

Beyond these frontrunners, the pipeline is expanding:

• Novo Nordisk filed for FDA approval of CagriSema in 2025, the first once-weekly combination of GLP‑1 and amylin analogue.
• Amycretin, Novo Nordisk’s oral dual GLP-1/amylin agonist, showed 13% weight loss in early trials, signaling a move toward multi-pathway oral therapies.
• Structure Therapeutics’ GSBR-1290 and Viking’s VK2735 are advancing differentiated mechanisms, while Roche and other players explore next-generation oral obesity medications.

For patients, oral therapies promise greater convenience, improved adherence, and broader access, particularly for those reluctant to use injectables. For manufacturers, this shift opens new competitive battlegrounds, where efficacy, tolerability, and pricing strategies will determine leadership in a new market dimension.

Pipeline Innovation: Beyond Weight Loss

The obesity pipeline remains robust, and IQVIA estimated there are over 193 assets in development as of October 2025, an increase from 181 assets in development in May 2025. Alongside an expanding pipeline, innovation is accelerating through new mechanisms of action (e.g., GIP/GLP-1 dual agonists, amylin analogs, and small molecules like orforglipron) and diversified routes of administration such as orals and ultra-long acting injectables.

The marketed obesity medications are entering a transformative era. Notably, innovation is moving beyond weight loss into a multi-system therapeutic frontier. Beyond label expansion, real-world studies have shown emerging evidence pointing to benefits in respiratory disorders, curbing addiction, and improving fertility ^[15]. The highly anticipated phase 3 EVOKE trial readout found that semaglutide did not significantly reduce progression of Alzheimer's disease.

Beyond new mechanisms, the next wave of innovation is reshaping how obesity medicines are delivered. Oral formulations are set to dominate headlines in 2026, offering convenience and eliminating cold-chain requirements - attributes that could make long-term obesity care more practical and unlock the maintenance opportunity. At the same time, ultra-long-acting injectables are emerging as another theme of innovation. Metsera’s pipeline includes MET-097i, a GLP-1 receptor agonist designed for once-monthly dosing, and MET-233i, an amylin analog being developed for monthly administration. These assets aim to move beyond the current weekly injection paradigm, signalling a future where extended dosing intervals could become central to maintenance strategies ^[16].