Svetlana Mojsov received the 2026 King Faisal Prize in Medicine on April 15 in Riyadh. It is her sixth major prize in three years for the same piece of work, done four decades ago.
The work. In 1983, Mojsov was a peptide chemist running an independent research facility at Massachusetts General Hospital. She read a recently published genetic sequence for a gut hormone and spotted something others had missed: the longer version of the molecule was an inactive precursor, and there was a shorter version inside it that did the actual biological work. Over six months, she synthesized the shorter version, made antibodies to it, and proved that it was the hormone that caused cells to release insulin when people ate.
That shorter version is now called GLP-1(7-37). It is the biological starting point for Ozempic, Wegovy, Mounjaro, Zepbound, and every drug in the weight-loss and diabetes class that has reshaped medicine over the last decade. Without Mojsov's identification of which part of the molecule mattered, none of these drugs exist in their current form.
What took so long. For most of the following forty years, the discovery was credited to other researchers. Mojsov was not a lab leader or a senior author on the initial high-profile publications. The correction started in 2023 with the Lasker Award, the most prestigious medical research prize in the United States. Then the Tang Prize, the Breakthrough Prize, the Princess of Asturias Prize, the VinFuture Prize, a National Academy of Sciences membership, and now King Faisal. Six major recognitions in three years for work that was done between 1983 and 1987.
A counter-note from the same week. A news feature in STAT reported that two of the scientists most identified with building the current GLP-1 drug class, Richard DiMarchi and Matthias Tschöp, are publicly arguing that the next generation of obesity drugs should not target GLP-1 at all. Their case is that the GLP-1 receptor has given most of what it can give at the individual-drug level. The next round of efficiency gains, they argue, will come from other biological targets, or from combining GLP-1 with others rather than treating it as the core.
That lands awkwardly in the same week as Mojsov's prize. The discovery is being publicly honored while the target is being publicly relitigated.
A note from our side. Our GLP-1 receptor page ↗ hosts 204 candidate peptides. Some of them push the GLP-1-only target. Others add glucagon (the receptor DiMarchi and Tschöp are pointing toward). Others mix in GIP or newer receptors. The science is not yet settled on whether the next big weight-loss drug will still call GLP-1 its main target. The discovery that unlocked the whole class, however, was and will remain Mojsov's.