Image: Kake ABC
In the first world war, munitions workers, known as “Canary Girls” for the yellow tinge the chemicals gave their skin, experienced sudden and dramatic weight loss. The cause was dinitrophenol, or DNP, an explosive ingredient that supercharged their metabolisms. By the 1930s, this toxic chemical was being sold in pill form as a miracle slimming drug, despite mounting evidence of its lethal side-effects.
The history of weight loss is littered with such dangerous shortcuts. From 19th-century thyroid extracts to the “fen-phen” diet-pill scandal of the 1990s, the desire for a simple pharmaceutical solution has consistently outpaced concerns about safety. Today science may finally be closing that gap, but new challenges are emerging.
The scale of the problem is immense. Since 1990 the number of obese adults worldwide has doubled, creating a massive burden of disease and associated economic costs. The recent success of injectable drugs such as Wegovy and Zepbound represents a genuine breakthrough. They are highly effective and safe too. Yet the ultimate prize in pharmaceutical circles has been an oral pill. Many patients simply prefer swallowing a tablet to an injection, making them more likely to stick with their treatment. The arrival of effective pills would mark a new chapter, transforming a niche treatment into a mainstream one.
Creating such a pill, however, has posed a tough biological puzzle. The new injectables mimic a hormone called GLP-1, which regulates appetite and blood sugar. The gut, however, is designed to break down proteins and peptides like GLP-1 before they can take effect. This is why until recently they could only be administered via injection. Novo Nordisk, a Danish drugmaker, has now created a pill version of its injectable semaglutide. The solution involves a protective chemical shield, known as SNAC, which helps the molecule survive the stomach and be absorbed into the bloodstream.
Eli Lilly, Novo’s main rival, has taken a different path. Rather than trying to protect a fragile large molecule, it has developed a smaller, synthetic one, known as orforglipron, that mimics GLP-1 but is not broken down by the gut. Both approaches are scientifically impressive; yet neither is perfect. Novo’s pill requires patients to fast before taking it and to avoid other medication for half an hour afterwards, a complication that could hinder long-term adherence. Lilly’s small molecule is easier to manufacture at scale, but must still prove it can match the safety profile of its established rivals.
The potential rewards for success are astronomical. The market for obesity drugs is projected to exceed $100bn a year by 2030, with oral medicines expected to claim between a fifth and a third of that. Pills would not only attract patients wary of needles but could also be more easily combined with other drugs to treat related conditions, such as diabetes and heart disease. The current duopoly will not last. A host of other pharmaceutical firms, from giants to start-ups, are racing to develop their own oral treatments, aiming for fewer side-effects and more convenient dosing.
The battleground will soon extend beyond wealthy Western markets. Historically, weight-loss drugs were a luxury. Yet nearly two-thirds of the world’s obese adults live in poorer countries. The future of the market will be shaped by emerging economies, particularly China and India. Both have vast urban populations, rising obesity and ambitious domestic pharmaceutical sectors. In China, inclusion in state-backed insurance schemes will be crucial for affordability. In India, a powerhouse of generic drugs, patent expirations beginning in 2026 will open the door to cheap copies, dramatically expanding access.
The ultimate reach of these medicines will depend on price and convenience. Injectables have, to the surprise of many, found widespread acceptance in rich countries. But pills are likely to accelerate the trend of direct-to-consumer marketing, where pharmaceutical companies use social-media influencers rather than just doctors to promote their wares. In the long run, increased competition and generic manufacturing should make treatments affordable for a far wider range of patients, including those who are less severely overweight or on lower incomes.
The development of an effective weight-loss pill is a story of scientific ingenuity overcoming decades of biological hurdles. Yet it also marks a transition into a more complex commercial phase, where manufacturing scale, marketing savvy and global pricing strategies will determine the winners. The quest for a simple slimming pill has long been driven by desperate demand. For the first time, science is offering a supply that is both powerful and safe. Making it accessible to the world, however, will be the next great challenge. ■
