Eli Lilly’s Weight-Loss Pill Falls Short, and Rivalry with Novo Nordisk Heats Up

The global race to dominate the lucrative weight-loss drug market took a sharp twist this week when American pharmaceutical powerhouse Eli Lilly unveiled late-stage trial results for its much-anticipated oral obesity treatment. The pill, orforglipron, helped patients lose an average of 12.4% of their body weight during the trial, a significant figure by most measures, but not quite enough for City expectations. Analysts had forecast a more impressive 13.7%, and the shortfall sent Lilly’s New York-listed shares tumbling 14.2% in a single trading session.

The news came just hours after Danish rival Novo Nordisk announced that its own oral obesity drug had produced roughly 15% weight loss in trials, enough to send its shares up 6.7% and hand it a symbolic advantage in this increasingly fierce contest.

Promise and Pitfalls

Eli Lilly had hoped that orforglipron would cement its dominance in a market it already leads with blockbuster injectable drugs Mounjaro and Zepbound. Like its competitors, the pill works by mimicking gut hormones that help regulate appetite and calorie intake.

The trial met its official targets and even revealed positive cardiovascular effects, a selling point that could help secure future NHS approvals. However, there was a drawback: participants reported nausea, vomiting, and other digestive issues more frequently than expected. Such side effects are common with this class of medication, but higher incidence rates risk denting patient compliance and GP confidence.

Strong Sales, Stronger Ambitions

Despite this setback, Lilly’s finances remain robust. In the second quarter, the company reported revenue of £12.1 billion (up 38% year-on-year). Demand for Mounjaro and Zepbound is so strong that the firm raised its 2025 full-year revenue guidance to between £46.4 billion and £47.9 billion, up from a previous forecast of £45 billion to £45.7 billion.

For investors and analysts, this reinforces a clear trend: the weight-loss drug market is ballooning and could be worth hundreds of billions of pounds globally within a decade. Pills are seen as the next breakthrough, offering a needle-free alternative that could appeal to millions more patients.

Nordic Momentum

For Novo Nordisk, Lilly’s stumble comes at an ideal moment. Already riding high from the runaway success of its injectables Wegovy and Ozempic, Novo is now awaiting US regulatory approval for its oral pill. A green light could allow the Danish firm to seize early market share in the tablet segment before Lilly’s pill reaches shelves. Both companies are already racing to secure manufacturing capacity and distribution networks, aware that whichever can scale fastest will hold a decisive advantage.

Political and Regulatory Hurdles

Yet the battle is not just scientific or commercial, it’s political. In Washington, moves are underway to expand Medicare’s power to negotiate prices on expensive medicines. While such reforms are not immediately on the UK’s agenda, they could ripple across global pricing strategies and put pressure on margins. If similar measures were ever adopted by the NHS, the impact on profit forecasts for obesity treatments could be profound.

The Next Chapter

Eli Lilly must now decide whether to press ahead with regulatory filings for orforglipron or tweak dosing to enhance results and reduce side effects. For Novo Nordisk, the task is simpler: push its pill to market quickly and capitalise on Lilly’s misstep.

Either way, the obesity drug sector remains in its infancy, and the rivalry between these two pharmaceutical titans looks set to define the next decade of the industry. In this contest, much like weight loss itself, small differences can mean the world, and fortunes will be made or lost on just a few percentage points.

Background: Novo Nordisk

Origins and Early History

Novo Nordisk is a Danish multinational pharmaceutical company headquartered in Bagsværd, just outside Copenhagen. It is widely recognised as one of the world’s largest producers of diabetes and obesity treatments.

The company’s roots stretch back to 1923, when two separate Danish pioneers in insulin production, Nordisk Insulinlaboratorium and Novo Terapeutisk Laboratorium, began manufacturing the hormone shortly after its discovery. These two firms merged in 1989 to form Novo Nordisk, combining nearly a century of expertise in diabetes care. From the outset, the company’s identity was shaped by a singular mission: developing reliable, high-quality treatments for people with diabetes.

Dominance in Insulin Production

Over the decades, Novo Nordisk became a global powerhouse in insulin manufacturing. By the mid-2010s, it controlled more than 45% of the global insulin market, supplying products ranging from human insulin to next-generation analogues. Its dominance rested not only on product innovation but also on its control of production from raw materials to finished vials and pens, a vertical integration strategy that remains a hallmark of its operations today.

Strategic Shift to Obesity Treatments

The company’s modern transformation began as obesity rates surged worldwide. Scientific research increasingly revealed strong links between obesity, type-2 diabetes, cardiovascular disease, and other chronic health conditions. Recognising both the public health challenge and commercial potential, Novo Nordisk moved aggressively into the weight-management sector.

The turning point was the development of semaglutide, a GLP-1 receptor agonist that mimics gut hormones regulating appetite and blood sugar levels. Initially launched as Ozempic for type-2 diabetes, semaglutide delivered impressive weight-loss results in clinical trials. This paved the way for its approval under the brand Wegovy for obesity management, a move that dramatically reshaped the company’s financial trajectory.

Financial Breakthrough and Market Leadership

The commercial success of Ozempic and Wegovy catapulted Novo Nordisk into a new league. In 2023, it became the most valuable publicly listed company in Europe by market capitalisation, overtaking luxury group LVMH. Analysts credited its leap not only to soaring demand for GLP-1 drugs, but also to the company’s ability to scale up production rapidly in an industry where manufacturing bottlenecks can cripple growth.

Manufacturing and Global Reach

Novo Nordisk operates major production facilities in Denmark, the United States, France, Brazil, and China, with a carefully controlled supply chain designed to protect both quality and efficiency. It has committed billions of pounds to expanding capacity, reflecting the unprecedented demand for its GLP-1 portfolio.

This manufacturing investment is especially critical given the strain on global supply: demand for Wegovy and Ozempic has often outpaced availability, forcing the company to ration supply in certain markets and prioritise the highest-need patients.

Challenges and Public Scrutiny

Despite its success, Novo Nordisk has faced mounting public and political scrutiny. In the United States, where list prices for Wegovy and Ozempic are among the highest in the world, debates over affordability have intensified. Critics argue that such prices place the drugs out of reach for many patients without generous insurance coverage, while defenders point to the high cost of innovation and manufacturing. Supply shortages have added to the challenge, sometimes frustrating healthcare providers and fuelling criticism that the company cannot meet demand at the pace it has stimulated it.

Leadership Change and Strategic Goals

In early 2025, Novo Nordisk replaced its long-standing chief executive, Lars Fruergaard Jørgensen in a bid to refresh leadership during a period of fierce rivalry with US-based Eli Lilly. The new leadership has made it clear that accelerating the rollout of its oral semaglutide for weight loss is a top priority. The company hopes this move will allow it to seize the initiative in the fast-growing oral obesity treatment segment and potentially beat Lilly’s forthcoming pill to market.

Scale and Future Outlook

Today, Novo Nordisk products are used by millions worldwide. Analysts estimate that its obesity drug portfolio could generate tens of billions of pounds annually within the decade, provided the company can maintain its market lead and navigate intensifying competition, regulatory pressure, and supply constraints.With obesity drugs increasingly seen as the pharmaceutical industry’s next blockbuster category, Novo Nordisk’s position at the top is both enviable and precarious, and the battle to keep it there is only just beginning.

Background: Eli Lilly

Eli Lilly and Company, based in Indianapolis, Indiana, is one of the most established names in the global pharmaceutical industry. Founded in 1876 by Colonel Eli Lilly, a veteran of the American Civil War and trained chemist, the company began with a mission to produce high-quality, science-based medicines at a time when much of the pharmaceutical market was unregulated and unreliable.

Over nearly 150 years, Eli Lilly has developed and commercialised a series of landmark medicines, including the first mass-produced insulin in the 1920s, penicillin during the Second World War, and pioneering cancer therapies. In more recent decades, the company became well-known for psychiatric drugs such as Prozac (fluoxetine) and Cymbalta (duloxetine).

In the 21st century, Lilly shifted significant resources toward metabolic disorders and biotechnology-based medicines. This focus produced some of the most talked-about treatments in recent years: the injectable drugs Mounjaro (tirzepatide) and its weight-loss branded version Zepbound (in the US). Tirzepatide belongs to a new generation of dual-hormone drugs that stimulate both GLP-1 and GIP receptors, enhancing appetite control and improving blood sugar regulation. Clinical results for these injectables have been remarkable, with some patients losing 20% or more of their body weight.

The commercial impact has been transformative. Lilly’s market value has surged in line with the soaring demand for obesity and diabetes medicines, making it one of the most valuable pharmaceutical companies in the world. In 2024 and 2025, sales of Mounjaro and Zepbound helped fuel double-digit revenue growth, and the company has been racing to expand manufacturing capacity to meet global demand.

Lilly’s research pipeline is also deep. Beyond orforglipron, its headline oral obesity drug candidate, the company is pursuing treatments in oncology, Alzheimer’s disease, immunology, and rare conditions. It operates in more than 100 countries, and has major research and manufacturing hubs in the US, Ireland, Puerto Rico, and China. However, the company is not without challenges. Like its Danish rival Novo Nordisk, Lilly faces supply constraints, regulatory scrutiny, and the looming threat of US drug-pricing reform. Future NHS uptake of its obesity medicines will likely depend on cost-effectiveness evaluations by NICE, adding another competitive hurdle in a rapidly expanding but politically sensitive market.

Background: Orforglipron

Orforglipron is Eli Lilly’s first oral GLP-1 receptor agonist designed specifically for the treatment of obesity and type-2 diabetes. Unlike the company’s hugely successful injectable drugs Mounjaro and Zepbound, orforglipron is taken as a once-daily tablet, offering a needle-free alternative for patients who are reluctant to use injections.

The drug belongs to the same broad family as other GLP-1 therapies, which work by mimicking naturally occurring gut hormones that help regulate appetite and food intake. By binding to the GLP-1 receptor, orforglipron triggers a sense of fullness, slows digestion, and reduces calorie consumption, leading to weight loss over time.

Eli Lilly has positioned orforglipron as a key strategic asset in its push to expand the reach of weight-loss treatments beyond specialist clinics and into mainstream GP prescribing, particularly important in countries where adoption often hinges on ease of use and cost-effectiveness.

One of orforglipron’s distinguishing features is that it is a non-peptide small-molecule drug. This makes it chemically more stable than peptide-based GLP-1 drugs, allowing it to be taken without the strict fasting or water-only requirements that limit some oral formulations. It could, in theory, be manufactured more cheaply and in larger quantities than biologic injectables, helping Lilly meet the surging global demand for obesity treatments.

However, trial data released in 2025 showed that while orforglipron achieved significant weight loss, an average of 12.4% body weight reduction, it fell short of market expectations. Side effects such as nausea and vomiting were also slightly more frequent than anticipated, raising questions about patient tolerability. Even so, the drug met its clinical endpoints and demonstrated cardiovascular benefits, which could strengthen its case for regulatory approval in both the US and Europe.

If approved, orforglipron could give Eli Lilly a crucial foothold in the emerging oral obesity drug segment, where rival Novo Nordisk is pushing ahead with its own high-profile candidate. For Lilly, the success or failure of this pill will help determine whether it can defend and expand its dominance in one of the fastest-growing sectors in global healthcare.

Conclusion

Eli Lilly’s underwhelming trial results for orforglipron mark a rare stumble for a company that has enjoyed a meteoric rise in the global weight-loss market. Yet the setback is far from fatal. With blockbuster injectables still driving record sales and a deep research pipeline, Lilly remains a formidable competitor. For Novo Nordisk, the timing could hardly be better. Stronger trial data for its own oral pill puts the Danish group in a position to seize momentum in the race to capture the emerging tablet segment, a market that could unlock millions of new patients worldwide, where convenience and cost will heavily influence NHS adoption.

As both firms push ahead, the rivalry is set to intensify, with manufacturing capacity, regulatory approvals, and pricing strategies likely to decide the winner. In an industry where a single percentage point of weight loss can sway billions in market value, the next phase of this contest promises to be as commercially brutal as it is scientifically ambitious.