What is a GLP-1?
GLP-1 stands for glucagon-like peptide-1, a hormone your gut releases after you eat. It raises insulin when blood sugar is high, slows the stomach and curbs appetite. GLP-1 medicines act on the same receptor and last far longer. FDA has approved 6 of these medicines, the first being Byetta, approved by FDA on Apr 28, 2005.
What GLP-1 does in your body
- Where it comes from. It is secreted by intestinal L-cells in response to nutrient ingestion: cells in the intestine release it when you eat.
- Blood sugar. It raises insulin and lowers glucagon around meals, which is why these medicines began as diabetes treatments.
- Stomach and appetite. It slows how fast the stomach empties and reduces food intake. Wegovy's label calls it a physiological regulator of appetite and caloric intake.
Every approved GLP-1, and what it is
What each is made from and how close it is to human GLP-1 come from its FDA label. Oldest first.
| Medicine | Acts on | Taken | Match to human GLP-1 | What its label says it is | First approved |
|---|---|---|---|---|---|
| ExenatideByetta (discontinued), Bydureon BCise (discontinued), Generic exenatide | GLP-1 | Twice daily (Byetta); once weekly (Bydureon BCise) | Not stated | Byetta (exenatide) is a synthetic peptide, GLP-1 receptor agonist, that was originally identified in the lizard Heloderma suspectum. Label | Apr 28, 2005 |
| LiraglutideVictoza, Saxenda | GLP-1 | Once daily | 97% | The peptide precursor of liraglutide, produced by a process that includes expression of recombinant DNA in Saccharomyces cerevisiae, has been engineered to be 97% homologous to native human GLP-1 by substituting arginine for lysine at position 34. Label | Jan 25, 2010 |
| DulaglutideTrulicity | GLP-1 | Once weekly | 90% | The molecule is a fusion protein that consists of 2 identical, disulfide-linked chains, each containing an N-terminal GLP-1 analog sequence covalently linked to the Fc portion of a modified human immunoglobulin G4 (IgG4) heavy chain by a small peptide linker and is produced using mammalian cell (Chinese hamster ovary) culture. Label | Sep 18, 2014 |
| SemaglutideOzempic, Wegovy, Wegovy HD, Rybelsus | GLP-1 | Once weekly (injectable); once daily (oral) | 94% | The peptide backbone is produced by yeast fermentation. Label | Dec 5, 2017 |
| TirzepatideMounjaro, Zepbound | GIP/GLP-1 | Once weekly | Not stated | Tirzepatide is based on the GIP sequence and contains aminoisobutyric acid (Aib) in positions 2 and 13, a C-terminal amide, and Lys residue at position 20 that is attached to 1,20-eicosanedioic acid via a linker. Label | May 13, 2022 |
| OrforglipronFoundayo | Small-molecule GLP-1 | Once daily | Not stated | Oral small-molecule GLP-1 receptor agonist Label | Apr 1, 2026 |
How GLP-1s arrived
Each brand's first approval, from Drugs@FDA and the Orange Book.
- ByettaApr 28, 2005
- VictozaJan 25, 2010
- BydureonJan 27, 2012
- TrulicitySep 18, 2014
- SaxendaDec 23, 2014
- Bydureon BCiseOct 20, 2017
- OzempicDec 5, 2017
- Rybelsus tablets, later also Ozempic tabletsSep 20, 2019
- WegovyJun 4, 2021
- MounjaroMay 13, 2022
- ZepboundNov 8, 2023
- Wegovy tabletsDec 22, 2025
- FoundayoApr 1, 2026
Which of these have a generic, and which patents still protect them
What people ask about GLP-1s
What does GLP-1 stand for?
Glucagon-like peptide-1. It is a hormone your own gut makes.
Is GLP-1 a hormone?
Yes. A 2019 review calls it "a multifaceted hormone with broad pharmacological potential". The medicines are not the hormone itself: they are made to act on the same receptor and last far longer.
What does a GLP-1 do?
A 2018 review says GLP-1 "released from gut enteroendocrine cells controls meal-related glycemic excursions through augmentation of insulin and inhibition of glucagon secretion", and that it also inhibits gastric emptying and food intake. Wegovy's FDA label calls it "a physiological regulator of appetite and caloric intake".
Is a GLP-1 a peptide?
The hormone is, and so are most of the medicines: their labels describe peptides or, for dulaglutide, a fusion protein. Orforglipron (Foundayo) is the exception, a small molecule taken as a tablet.
Is Ozempic a GLP-1? Is Mounjaro?
Ozempic, Wegovy and Rybelsus contain semaglutide, a GLP-1 receptor agonist. Mounjaro and Zepbound contain tirzepatide, which acts on two receptors, GIP and GLP-1. 6 approved medicines are listed below with their brands.
What is the difference between GLP-1 and GIP?
They are two different gut hormones with their own receptors. Tirzepatide acts on both. Its label says nonclinical studies suggest GIP may further contribute to regulating food intake.
What is the difference between GLP-1 and GLP-2?
GLP-2 is a separate hormone, and no weight-loss medicine acts on it. FDA's label for teduglutide (Gattex), a GLP-2 analog used in short bowel syndrome, describes GLP-2 as "a peptide secreted by L-cells of the distal intestine" that increases intestinal blood flow.
What is GLP-3?
We found no hormone or FDA label by that name. It is an informal nickname for retatrutide, which acts on three receptors: GIP, GLP-1 and glucagon. Retatrutide is not FDA approved. Medicines still in trials
How long have GLP-1s been around?
The first was Byetta, approved by FDA on Apr 28, 2005. Every first approval FDA records for these brands is listed on this page.
Can you buy a GLP-1 over the counter?
No. Every medicine on this page is prescription only. Patches and supplements sold under the GLP-1 name are not these medicines. What GLP-1 patches actually contain
Are GLP-1s safe?
FDA approved them after trials, and each label lists serious warnings as well. Which ones apply depends on the medicine and on you, so read each label's warnings with your clinician. GLP-1 side effects compared
Reviews read on Nov 6, 2026: Drucker, Cell Metabolism, 2018, Muller et al., Molecular Metabolism, 2019, PubMed review, 2026, and on retatrutide N Engl J Med, 2023.