Is it a GLP-1?
Direct answer
What you need to know
Evidence strength: StrongA drug is a GLP-1 medication if it binds and activates the GLP-1 receptor, and its own label says so in one sentence. Trulicity, Victoza, Byetta, Ozempic, Wegovy and Foundayo do. Mounjaro and Zepbound do that and something else. Symlin does not, and neither does a DPP-4 inhibitor like Januvia — which is where the phrase “GLP-1 inhibitor” comes from, and why it describes nothing that exists.
Key takeaways
- The test is the receptor, and every label states its own answer in section 12.1.
- Symlin is an amylin analogue. Same injection, same conditions, different hormone.
- A DPP-4 inhibitor raises your GLP-1 rather than supplying a copy — a different class, not a weaker version.
- Tirzepatide is a dual agonist, so “a GLP-1” understates it.
Important limitation: Classification is not comparison. Being in this class says nothing about how well a drug works, what it costs, or whether it suits you, and the homology figures below are a measure of resemblance rather than of strength.
Next action: If you were trying to separate the hormone from the medicines, that is its own question — see how GLP-1 works, hormone and drug.
Primary sources: DailyMed — Rybelsus / Ozempic tablets prescribing information, DailyMed — Victoza prescribing information, DailyMed — Trulicity prescribing information
General education, not medical advice. If you are unsure what you have been prescribed, the label and your pharmacist are the authorities, not a web page.
The ones that are
Each row quotes the drug’s own mechanism-of-action section. Where a label states how closely the molecule resembles the natural hormone, that figure is in the next table.
| Brand names | Molecule | What its label says |
|---|---|---|
| Ozempic, Wegovy, Rybelsus | semaglutide | “Semaglutide is a GLP-1 analogue with 94% sequence homology to human GLP-1. Semaglutide acts as a GLP-1 receptor agonist that selectively binds to and activates the GLP-1 receptor, the target for native GLP-1.” |
| Victoza, Saxenda | liraglutide | “Liraglutide is an acylated human GLP-1 receptor agonist with 97% amino acid sequence homology to endogenous human GLP-1(7-37).” |
| Trulicity | dulaglutide | “TRULICITY contains dulaglutide, which is a human GLP-1 receptor agonist with 90% amino acid sequence homology to endogenous human GLP-1 (7-37).” |
| Byetta, Bydureon | exenatide | “BYETTA is a GLP-1 receptor agonist that enhances glucose-dependent insulin secretion by the pancreatic beta-cell, suppresses inappropriately elevated glucagon secretion, and slows gastric emptying.” |
| Foundayo | orforglipron | A non-peptide small molecule that activates the GLP-1 receptor — the first of its structural kind approved, and the reason it is a tablet with no food or water timing restriction. |
| Mounjaro, Zepbounddual agonist | tirzepatide | “Tirzepatide is a GIP receptor and GLP-1 receptor agonist… Tirzepatide selectively binds to and activates both the GIP and GLP-1 receptors, the targets for native GIP and GLP-1.” |
How close to the real hormone, in the labels’ own numbers
Three of these labels state how much of the natural hormone’s amino-acid sequence the drug shares. They are rarely printed together, and set side by side they show something worth knowing: these are near-copies of a hormone you already make, differing from it and from each other by a few percent.
| Molecule | Homology to human GLP-1 |
|---|---|
| dulaglutideTrulicity | 90% |
| semaglutideOzempic, Wegovy, Rybelsus | 94% |
| liraglutideVictoza, Saxenda | 97% |
This is not a ranking. Liraglutide is the closest to the natural hormone on this measure and is not the strongest drug in the class — semaglutide and tirzepatide both produce larger weight reductions in their trials. Homology describes resemblance and nothing else. What actually separates these drugs is how long they last in the body and how strongly they hold the receptor, which is a different property from how much they look like the original.
The ones that are not
Both of these are injected or prescribed alongside the real thing, and both are asked about often enough to belong here.
Symlin, SymlinPen — pramlintide
“Pramlintide is an analog of human amylin. Amylin is colocated with insulin in secretory granules and cosecreted with insulin by pancreatic beta cells in response to food intake.”
It is an injected hormone analogue for diabetes that slows gastric emptying and reduces appetite — the same headline effects — so it reads like one of these drugs from the outside. It imitates amylin, a different hormone, and does not touch the GLP-1 receptor.
Januvia, Janumet — sitagliptin, and DPP-4 inhibitors generally
“Sitagliptin is a DPP-4 inhibitor, which is believed to exert its actions… by slowing the inactivation of incretin hormones. Concentrations of the active intact hormones are increased by sitagliptin.”
This is the closest call on the page, and the one behind searches for a “GLP-1 inhibitor”. A DPP-4 inhibitor does act on GLP-1 — by blocking the enzyme that breaks your own GLP-1 down, so more of it survives. It raises your natural hormone rather than supplying a copy of it, which is why it is a tablet, why the effect is far smaller, and why it is not in this class. There is no such thing as a GLP-1 inhibitor: these drugs are agonists, and the inhibitor is the other class.
There is no GLP-1 inhibitor. The drugs are agonists, and the inhibitor is a different class doing a quieter version of the same job.
Common questions
- Is Symlin a GLP-1?
- No. Symlin is pramlintide, and its label describes it as an analog of human amylin — a different hormone. It is injected, it is for diabetes, and it slows gastric emptying and reduces appetite, which is why it is so often mistaken for one. It does not act on the GLP-1 receptor.
- Is Trulicity a GLP-1?
- Yes. Trulicity is dulaglutide, and its label calls it a human GLP-1 receptor agonist with 90% amino acid sequence homology to endogenous human GLP-1.
- What is a GLP-1 inhibitor?
- There is no such thing, and the phrase usually means one of two drugs. GLP-1 medications are agonists — they activate the GLP-1 receptor. DPP-4 inhibitors, such as sitagliptin, are a separate class that blocks the enzyme breaking your own GLP-1 down, raising your natural hormone instead of supplying a copy of it.
- Is GLP-1 the same as Ozempic?
- No, though they are related. GLP-1 is a hormone your gut releases after eating, and it is also the name of a drug class. Ozempic is one brand of one drug in that class — semaglutide. Every Ozempic is a GLP-1 medication; most GLP-1 medications are not Ozempic.
- Is Mounjaro a GLP-1?
- Partly, and the distinction matters. Tirzepatide activates the GLP-1 receptor and the GIP receptor, so its label describes it as a GIP receptor and GLP-1 receptor agonist. Calling it simply a GLP-1 leaves out half of what it does.
Sources
Each source below supports specific statements on this page. We cite the strongest available authority and verify against the current version before publishing.
- Ozempic prescribing informationDailyMed — Rybelsus / Ozempic tablets prescribing informationSupports: Mechanism of action for semaglutide, which is how Ozempic is classified on this page.
- Victoza prescribing informationDailyMed — Victoza prescribing informationSupports: Mechanism of action for liraglutide, which is how Victoza is classified on this page.
- Trulicity prescribing informationDailyMed — Trulicity prescribing informationSupports: Mechanism of action for dulaglutide, which is how Trulicity is classified on this page.
- Byetta prescribing informationDailyMed — Byetta prescribing informationSupports: Mechanism of action for exenatide, which is how Byetta is classified on this page.
- Foundayo prescribing informationDailyMed — Foundayo prescribing informationSupports: Mechanism of action for orforglipron, which is how Foundayo is classified on this page.
- Mounjaro prescribing informationDailyMed — Mounjaro prescribing informationSupports: Mechanism of action for tirzepatide, which is how Mounjaro is classified on this page.
- Symlin prescribing informationDailyMed — SymlinPen prescribing informationSupports: Mechanism of action for pramlintide, which is how Symlin is classified on this page.
- Januvia prescribing informationDailyMed — Januvia prescribing informationSupports: Mechanism of action for sitagliptin, and DPP-4 inhibitors generally, which is how Januvia is classified on this page.
This page is general education, not medical advice. Talk to your own healthcare provider about your situation before starting, stopping, or changing any medication.