GLP-1 Glossary: Every Term, Abbreviation and Brand Name Decoded
A plain-English glossary of GLP-1 terms — drug names (generic + brand), abbreviations, mechanism terms, related drug classes, and the typos people search.
The GLP-1 space has accumulated a forest of terms — multiple drug names for the same molecule, several spellings of the same abbreviation, related-but-distinct drug classes, and a couple of search-engine typos that get used as if they're real terms. This glossary covers all of it.
The core terms
GLP-1 Glucagon-like peptide-1. A 30- or 31-amino-acid hormone naturally released by the small intestine after meals. Stimulates insulin release, suppresses glucagon, slows gastric emptying and suppresses appetite.
GLP-1 receptor The protein the GLP-1 hormone (and its drug mimics) bind to. Found on pancreatic beta cells, neurons in the brain, GI tract cells, heart and other tissues.
GLP-1 receptor agonist (GLP-1 RA) A drug that activates the GLP-1 receptor, mimicking the effects of the natural hormone. The full drug class. Examples: semaglutide, tirzepatide, liraglutide.
GLP-1 analog Synonym for GLP-1 receptor agonist when the drug is a peptide closely resembling the natural hormone (e.g., semaglutide). Some recent agents are small molecules rather than analogs — they're agonists but not analogs.
GLP-1 agonist Common shorthand for GLP-1 receptor agonist.
Search-engine variants of "GLP-1"
People type the term many ways. They all mean the same hormone / drug class:
- GLP1, GLP 1, GL P1, GL P 1, g lp 1 — variant spellings of GLP-1
- glp1s, GLP-1's — plural forms
- glp 1i, GLP1 i — typos for GLP-1 (or attempts to refer to "GLP-1 inhibitor", which isn't really a drug class)
If you searched for any of these, you're looking for GLP-1 receptor agonists — the drugs covered throughout this site.
Common mix-ups: "GLP-1 inhibitor"
"GLP-1 inhibitor" is not a real drug class. People searching this term usually mean one of two things:
- GLP-1 receptor agonists (what GLP-1 drugs actually are)
- SGLT2 inhibitors — a different diabetes drug class: empagliflozin (Jardiance), dapagliflozin (Farxiga), canagliflozin (Invokana)
See GLP-1 vs SGLT2 inhibitors.
Related hormones and classes
GIP Glucose-dependent insulinotropic polypeptide. A second incretin hormone, alongside GLP-1. Activated by tirzepatide and retatrutide.
GLP-2 A different peptide derived from the same proglucagon gene as GLP-1. Involved in gut growth and intestinal barrier function. Not a target of the current GLP-1 receptor agonists.
Glucagon The hormone that opposes insulin — raises blood sugar by prompting the liver to release stored glucose. Targeted (in combination with GLP-1 and GIP) by retatrutide for its energy-expenditure effects.
Amylin A pancreatic hormone that complements insulin, slowing gastric emptying and reducing appetite. Targeted by cagrilintide (the second molecule in Novo's upcoming CagriSema combination).
Incretin Category of hormones (GLP-1, GIP) released by the gut that increase insulin secretion in response to eating. The "incretin effect" is the finding that oral glucose triggers more insulin release than IV glucose.
DPP-4 Dipeptidyl peptidase-4. The enzyme that rapidly breaks down endogenous GLP-1 (giving it a 2-minute half-life). DPP-4 inhibitor drugs (sitagliptin / Januvia, etc.) work by blocking this enzyme to boost endogenous GLP-1.
DPP-4 inhibitor A different drug class that boosts endogenous GLP-1 by blocking the DPP-4 enzyme. Less potent than GLP-1 receptor agonists. Examples: sitagliptin (Januvia), linagliptin (Tradjenta).
Drug classes by mechanism
| Class | Receptors activated | Examples |
|---|---|---|
| Single GLP-1 RA | GLP-1 | Semaglutide, liraglutide, dulaglutide |
| Dual agonist (GLP-1/GIP) | GLP-1 + GIP | Tirzepatide |
| Triple agonist | GLP-1 + GIP + glucagon | Retatrutide (Phase 3) |
| Dual GLP-1/glucagon | GLP-1 + glucagon | Survodutide, pemvidutide (in development) |
| Bispecific antibody-peptide | GLP-1 agonist + GIP antagonist | MariTide (Amgen, in development) |
| GLP-1 + amylin combination | Two molecules, both pathways | CagriSema (Phase 3) |
| DPP-4 inhibitor | Boosts endogenous GLP-1 | Sitagliptin (Januvia) |
Drug names: generic → brand
| Generic name | Brand name(s) | Indication(s) |
|---|---|---|
| Semaglutide | Ozempic (T2D inj), Wegovy (weight inj), Rybelsus (T2D oral), Wegovy oral (weight) | T2D, weight, CV risk, MASH |
| Tirzepatide | Mounjaro (T2D), Zepbound (weight + OSA) | T2D, weight, OSA |
| Liraglutide | Victoza (T2D), Saxenda (weight) | T2D, weight |
| Dulaglutide | Trulicity | T2D |
| Exenatide | Byetta (twice daily), Bydureon (weekly) | T2D |
| Lixisenatide | Adlyxin | T2D |
| Albiglutide | Tanzeum (discontinued 2018) | T2D |
| Orforglipron | Foundayo | Weight |
| Cagrilintide | (not yet branded, part of CagriSema) | Weight |
| Survodutide | (not yet branded, Phase 3) | Weight + MASH |
| Pemvidutide | (not yet branded, Phase 2/3) | Weight + MASH |
| Retatrutide | (not yet branded, Phase 3) | Weight |
| Mazdutide | (Lilly / Innovent, approved in China) | Weight |
| MariTide | (Amgen development name) | Weight |
| Danuglipron | (Pfizer development name) | Weight |
Other key terms
STEP — Novo Nordisk's Phase 3 trial program for semaglutide in obesity (STEP-1 through STEP-4, STEP-TEEN, etc.).
SUSTAIN — Novo Nordisk's Phase 3 program for semaglutide in T2D.
SELECT — Novo's cardiovascular outcomes trial for semaglutide in patients with obesity and CVD. Showed 20% MACE reduction.
SURPASS — Eli Lilly's Phase 3 program for tirzepatide in T2D.
SURMOUNT — Eli Lilly's Phase 3 program for tirzepatide in obesity.
TRIUMPH — Eli Lilly's Phase 3 program for retatrutide.
OASIS — Novo's Phase 3 program for oral Wegovy.
ATTAIN — Lilly's Phase 3 program for orforglipron / Foundayo.
STEP-1 — The pivotal Wegovy trial showing 15% average weight loss at 68 weeks.
SURMOUNT-1 — The pivotal Zepbound trial showing 21% average weight loss at 72 weeks.
MACE — Major adverse cardiovascular events. Heart attack, stroke, cardiovascular death.
MASH — Metabolic-associated steatohepatitis. Liver disease driven by metabolic factors. Wegovy is approved for MASH with fibrosis.
NASH — Older name for MASH. Same disease; nomenclature updated.
MTC — Medullary thyroid carcinoma. The thyroid cancer signal from rodent studies that earned GLP-1s their boxed warning.
MEN-2 — Multiple endocrine neoplasia syndrome type 2. A genetic condition associated with MTC. Personal or family history is a contraindication for GLP-1s.
OSA — Obstructive sleep apnea. Zepbound is approved for moderate- to-severe OSA in adults with obesity.
T2D — Type 2 diabetes.
BMI — Body mass index.
FDA — US Food and Drug Administration.
503A pharmacy — A traditional US compounding pharmacy that prepares medications for individual patients with patient-specific prescriptions.
503B outsourcing facility — A larger-scale FDA-regulated compounding facility that can prepare batches for office use or during drug shortages.
LillyDirect — Eli Lilly's direct-to-consumer pharmacy program; sells Zepbound vials and Foundayo at reduced cash prices.
NovoCare Pharmacy — Novo Nordisk's direct-to-consumer pharmacy program; sells Wegovy and other Novo products at reduced cash prices.
Compounded GLP-1 — Same active molecule as brand-name (semaglutide or tirzepatide) but prepared by a US-licensed compounding pharmacy rather than the original manufacturer. See compounded GLP-1.
Research peptide — Vials sold as "for laboratory research only, not for human consumption." Not pharmaceutical products. Not a legal route for clinical use.
Microdosing — Informal term for staying at or below the lowest approved dose of a GLP-1. See GLP-1 microdosing.
Titration — The process of gradually increasing a drug dose from starter to target over several weeks. Standard for all GLP-1s.
Maintenance dose — The sustained dose after titration completes. For Wegovy this is 2.4 mg/week; for Zepbound, 5-15 mg/week.
Off-label use — Using a drug for an indication not on its FDA approval. Common with GLP-1s (e.g., using Ozempic for weight loss).
FAQ
What does GLP-1 stand for? Glucagon-Like Peptide-1.
What's the difference between GLP-1, GLP1 and GLP 1? Same thing. Different spellings/formats of the same abbreviation.
Is "GLP-1 agonist" the same as "GLP-1 receptor agonist"? Yes. The shorter form is colloquial.
Is "GLP-1 inhibitor" a real drug class? No. People searching that term usually mean GLP-1 receptor agonists or the unrelated SGLT2 inhibitors.
Are all the GLP-1 drug brands the same? No. Different brands have different molecules, indications, doses and prices. See GLP-1 drugs list.
This article is for educational purposes only and is not medical advice. GLP-1 medications are prescription drugs. Consult a qualified healthcare professional for treatment decisions.