As of 2025, Eli Lilly's tirzepatide portfolio (Mounjaro and Zepbound) surpassed $36.5 billion in combined sales, amounting to approximately 54 trillion won. This marks a historic milestone, outpacing the $31.6 billion sales of Merck's (MSD) immune-oncology drug Keytruda, which had long held the number one spot in the global pharmaceutical market.
The dominance of oncology, which the global pharmaceutical industry had firmly maintained for decades, was upended in just two to three years, driven at its core by an unprecedented class of new drugs: GLP-1 receptor agonist obesity treatments.
Why is a simple weight-loss medication shaking up the global pharmaceutical industry? To understand why, one needs to examine the redefinition of obesity as a disease, the technological innovations that made treatment possible, and the simultaneous convergence of three key pillars: pricing, accessibility, and policy.
Obesity Is No Longer a Matter of Willpower
In late 2025, the World Health Organization (WHO) released its first global guidelines recommending the use of GLP-1