GLP-1 as a hormone was discovered in 1986, and the first GLP-1 drug reached patients in 2005. That means the science behind today’s blockbuster weight loss and diabetes medications has nearly four decades of history, while the drugs themselves have been in clinical use for about 20 years.
The Hormone Behind It All: 1986
The story starts with two researchers, Joel Habener and Svetlana Mojsov, who identified the hormone GLP-1(7-37) in the intestine in 1986. They found it was a byproduct of glucagon, a well-known hormone involved in blood sugar regulation. What made GLP-1 exciting was its role as an “incretin,” a gut hormone that signals the pancreas to release insulin after eating. The body naturally produces GLP-1, but it breaks down extremely fast, with a half-life of roughly two minutes. That rapid breakdown meant scientists couldn’t simply inject the natural hormone and expect it to work as a medication. Solving that problem took nearly two decades.
Habener and Mojsov received the 2024 Lasker~DeBakey Clinical Medical Research Award for this discovery, one of the most prestigious honors in medicine, a recognition of just how transformative that 1986 finding turned out to be.
First GLP-1 Drug: 2005
The first GLP-1 drug to reach patients was exenatide, approved by the FDA in 2005 for type 2 diabetes. It was derived from a compound found in Gila monster saliva, which naturally resists the enzyme that breaks down human GLP-1 so quickly. Patients injected it twice daily. It worked, but the dosing schedule was inconvenient, and the drug was a stepping stone more than a destination.
Once-Daily Dosing Arrives: 2010
Liraglutide (sold as Victoza) won FDA approval in January 2010 as the first once-daily GLP-1 injection for type 2 diabetes. Its molecular structure is 97% identical to the body’s own GLP-1, but small modifications gave it a much longer half-life, enough that one shot per day kept blood sugar controlled. This was a significant convenience improvement and helped the drug class gain wider adoption among patients and doctors.
The Jump to Weight Loss: 2014
For nearly a decade, GLP-1 drugs were strictly diabetes medications. That changed in December 2014 when the FDA approved a higher dose of liraglutide, branded as Saxenda, specifically for chronic weight management. It was the first time a GLP-1 drug carried an official obesity indication. Saxenda was approved for adults with a BMI of 30 or higher, or 27 or higher with at least one weight-related condition like high blood pressure or high cholesterol. This approval marked the moment GLP-1 drugs crossed from endocrinology into mainstream weight management.
Weekly Injections Change the Game
An extended-release version of exenatide brought dosing down to once per week, a major shift in patient experience. But the real breakthrough in weekly dosing came with semaglutide. Approved as Ozempic for type 2 diabetes and later as Wegovy for weight management, semaglutide delivered stronger results in both blood sugar control and weight loss than earlier GLP-1 drugs. Wegovy became one of the most talked-about medications in modern medicine, largely because clinical trials showed patients losing a significant percentage of their body weight.
In March 2024, the FDA expanded Wegovy’s approval to include reducing the risk of heart attack, stroke, and cardiovascular death in adults with heart disease who also have obesity or are overweight. This was the first drug approved specifically to lower serious heart risks in that population, pushing GLP-1 medications well beyond their original purpose of blood sugar management.
Dual-Action Drugs: 2023
The newest generation doesn’t target GLP-1 alone. Tirzepatide, approved as Zepbound for weight management in November 2023, activates both GLP-1 receptors and a second gut hormone receptor called GIP. By hitting two pathways that regulate appetite and blood sugar, tirzepatide produces even greater weight loss in clinical trials than semaglutide. Its approval for obesity followed an earlier approval for type 2 diabetes under the brand name Mounjaro.
A Timeline at a Glance
- 1986: GLP-1 hormone discovered in the intestine
- 2005: First GLP-1 drug (exenatide) approved for type 2 diabetes
- 2010: First once-daily GLP-1 injection (liraglutide) approved
- 2014: First GLP-1 drug approved for weight loss (Saxenda)
- 2017–2021: Semaglutide approved for diabetes (Ozempic), then weight loss (Wegovy)
- 2023: First dual GLP-1/GIP drug (tirzepatide) approved for weight loss
- 2024: Wegovy approved to reduce heart attack and stroke risk
From a laboratory finding in 1986 to the most in-demand prescriptions in 2024, GLP-1 drugs have been in development for close to 40 years and in patients’ hands for 20. What started as a niche diabetes treatment has expanded into weight management, heart disease prevention, and a drug class that shows no sign of slowing down.