Joel Habener, Svetlana Mojsov, and Dan Drucker

The advent of effective weight-loss medications like Wegovy is the culmination of years of teamwork. Scientists in Europe and the U.S., first working on diabetes drugs, made a critical connection between insulin and incretins, part of a family of gut hormones known as glucagons, thus helping them to understand how to manage blood-sugar levels and weight. At the University of Copenhagen, Jens Juul Holst noticed that after intestinal surgery, the hormone glucagon increased people’s insulin levels. Around the same time, Joel Habener and Dan Drucker, from Massachusetts General Hospital, discovered two forms of glucagon, including GLP-1, a form of which is now in Ozempic, Wegovy, Mounjaro, and Zepbound; and Svetlana Mojsov, a chemist, synthesized GLP-1 and developed antibodies against it for critical early studies. Drucker’s experiments pinpointed the specific parts of GLP-1 responsible for affecting insulin levels. Now GLP-1-based medications are approved in the U.S. to treat diabetes and obesity, and to reduce the risk of heart disease. And there’s more to come—researchers are studying other potential benefits of GLP-1 drugs, including lowering the risk of Alzheimer’s, Parkinson’s, kidney, and liver diseases.

Park is a TIME senior correspondent