GLP-1: What It Is, How It Works, and Every FDA-Approved Medication (2026)
GLP-1 (glucagon-like peptide-1) is a gut hormone that controls appetite and blood sugar. The class of medications that mimic it — GLP-1 receptor agonists — includes Wegovy, Zepbound, Foundayo, Ozempic, Mounjaro, Saxenda, Rybelsus, Trulicity, Victoza, and Byetta. Below: what GLP-1 actually is, how the medications work, and a verified side-by-side comparison of every one of them.
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About this page
Every drug listed below is FDA-approved with a published label on DailyMed (NIH-hosted) or Drugs@FDA. Indication, mechanism, administration route, and approval-date data are pulled from our primary-source-verified drug database. We do not paraphrase indication language and we do not invent comparisons that the published evidence does not support. For verbatim FDA-label quotes and clinical-trial citations on any individual drug, follow the “Full guide” link to that drug's page.
What is GLP-1?
GLP-1 stands for glucagon-like peptide-1. It is a 30-amino-acid incretin hormone secreted by enteroendocrine L-cells in the distal small intestine and colon in response to food intake. The full proglucagon gene encodes both glucagon (in pancreatic alpha cells) and GLP-1 (in intestinal L-cells) — the two are biologically opposite signals using related peptide structures.
GLP-1 has four well-characterized physiologic actions:
- Glucose-dependent insulin secretion. GLP-1 binds the GLP-1 receptor on pancreatic beta cells and amplifies insulin release — but only when blood glucose is elevated. This is the “glucose-dependent” property that makes it safe with respect to hypoglycemia vs older diabetes drugs.
- Glucagon suppression. GLP-1 reduces glucagon secretion from pancreatic alpha cells, lowering hepatic glucose production.
- Delayed gastric emptying. GLP-1 slows the rate at which the stomach empties food into the small intestine, blunting post-meal blood sugar spikes and prolonging satiety.
- Central appetite suppression. GLP-1 receptors are also expressed in the brain — primarily in the hypothalamus and brainstem — where activation reduces hunger and food reward signaling.
Native (endogenous) GLP-1 has a half-life of about 1–2 minutes — it is rapidly degraded by the enzyme dipeptidyl peptidase-4 (DPP-4). This is why pharmaceutical GLP-1s are engineered to resist DPP-4 cleavage, extending the half-life from minutes to hours (liraglutide, exenatide twice-daily) or to days (semaglutide, tirzepatide, dulaglutide).
How GLP-1 medications work
GLP-1 receptor agonists are a class of medications that bind and activate the same GLP-1 receptor as the native hormone. They reproduce all four physiologic actions above, with two clinical consequences:
Type 2 diabetes glycemic control
Improved insulin secretion + reduced glucagon + slower gastric emptying together lower fasting and post-meal blood glucose, producing A1C reductions of 1.0–2.5 percentage points across the class. This was the original FDA-approved indication for the entire class starting with Byetta in 2005.
Chronic weight management
Delayed gastric emptying + central appetite suppression produce sustained reductions in food intake, leading to meaningful body-weight loss. This indication was first added with Saxenda (liraglutide 3 mg) in 2014 and expanded with Wegovy (semaglutide 2.4 mg) in 2021, Zepbound (tirzepatide) in 2023, and Foundayo (orforglipron) in 2026.
Tirzepatide (Mounjaro / Zepbound) is a dual GIP / GLP-1 receptor agonist — it activates BOTH the GLP-1 receptor AND the GIP (glucose-dependent insulinotropic polypeptide) receptor simultaneously. The dual mechanism is associated with greater A1C and weight reductions than pure-GLP-1 agonists in published head-to-head trials. Retatrutide (investigational, see our retatrutide evidence article) extends this further to a triple agonist (GLP-1 / GIP / glucagon).
Foundayo (orforglipron) is the first oral, non-peptide small-molecule GLP-1 receptor agonist — structurally distinct from the modified-peptide drugs above. Unlike Rybelsus (oral semaglutide, which IS a modified peptide and requires a special absorption-enhancer and fasted administration), Foundayo can be taken without water-volume or fasting restrictions.
Every FDA-approved GLP-1 medication, compared
All 11 FDA-approved GLP-1 receptor agonists in 2026, with primary-source-verified FDA-approval dates, indication, administration route, and manufacturer. Every label cited below was pulled live from DailyMed (NIH) on 2026-05-09. Two drugs in the table — Byetta and Bydureon BCise — were discontinued by AstraZeneca in October 2024 and are flagged as historical references.
| Brand | Generic | Indication | Manufacturer | Guide |
|---|---|---|---|---|
| Wegovy | Semaglutide | Weight management | Novo Nordisk | Wegovy → |
| Zepbound | Tirzepatide | Weight management | Eli Lilly | Zepbound → |
| Foundayo | Orforglipron | Weight management | Eli Lilly | Foundayo → |
| Ozempic | Semaglutide | Type 2 diabetes | Novo Nordisk | Ozempic → |
| Mounjaro | Tirzepatide | Type 2 diabetes | Eli Lilly | Mounjaro → |
| Saxenda | Liraglutide 3 mg | Weight management | Novo Nordisk | DailyMed → |
| Rybelsus | Semaglutide (oral) | Type 2 diabetes | Novo Nordisk | DailyMed → |
| Trulicity | Dulaglutide | Type 2 diabetes | Eli Lilly | DailyMed → |
| Victoza | Liraglutide 1.8 mg max | Type 2 diabetes | Novo Nordisk | DailyMed → |
| ByettaDiscontinued | Exenatide (twice-daily) | Type 2 diabetes | AstraZeneca | DailyMed → |
| Bydureon BCiseDiscontinued | Exenatide extended-release | Type 2 diabetes | AstraZeneca | DailyMed → |
Generic + discontinuation context for the legacy GLP-1s
- Saxenda (Liraglutide 3 mg, Novo Nordisk) — FDA-approved Dec 2014. First generic liraglutide for weight management launched by Teva on Aug 27, 2025. DailyMed label
- Rybelsus (Semaglutide (oral), Novo Nordisk) — FDA-approved Sep 2019. First oral GLP-1 RA. Cardiovascular risk-reduction indication added Oct 17, 2025 (7 mg + 14 mg only) per the SOUL trial. DailyMed label
- Trulicity (Dulaglutide, Eli Lilly) — FDA-approved Sep 2014. Long-acting GLP-1 RA. CV risk-reduction indication added (REWIND trial, Lancet 2019). Fc-fusion biologic — only the 351(k) biosimilar pathway applies; no biosimilar approved as of 2026-05-09. DailyMed label
- Victoza (Liraglutide 1.8 mg max, Novo Nordisk) — FDA-approved Jan 2010. Same molecule as Saxenda, lower-dose for diabetes. First generic GLP-1 RA in the US — generic liraglutide (Hikma) FDA-approved + launched Dec 2024. DailyMed label
- Byetta (Exenatide (twice-daily), AstraZeneca) — FDA-approved Apr 2005. First GLP-1 RA approved in the US. DISCONTINUED by AstraZeneca on Oct 25, 2024. Generic exenatide (Amneal) FDA-approved Nov 21, 2024 — historical reference. No boxed warning. DailyMed label
- Bydureon BCise (Exenatide extended-release, AstraZeneca) — FDA-approved Oct 2017 (BCise device). Extended-release exenatide microspheres. DISCONTINUED by AstraZeneca on Oct 28, 2024. No biosimilar approved (complex microsphere + autoinjector). DailyMed label
All labels above were pulled live from DailyMed (NIH) on 2026-05-09 with verbatim text extraction. SetIDs are stable canonical references — they do not change when labels are revised. Discontinuation dates sourced from UnitedHealthcare provider-notice citing AstraZeneca's October 2024 announcement.
Weight management vs type 2 diabetes — why brand names differ
A confusion-point for new patients: the same active ingredient is sold under different brand names depending on the FDA-approved indication.
Semaglutide
- Wegovy — chronic weight management (subcutaneous, 2.4 mg weekly)
- Ozempic — type 2 diabetes (subcutaneous, up to 2 mg weekly)
- Rybelsus — type 2 diabetes (oral tablet, up to 14 mg daily)
Tirzepatide
- Zepbound — chronic weight management + obstructive sleep apnea in obesity (subcutaneous, up to 15 mg weekly)
- Mounjaro — type 2 diabetes (subcutaneous, up to 15 mg weekly)
Liraglutide
- Saxenda — chronic weight management (subcutaneous, 3 mg daily)
- Victoza — type 2 diabetes (subcutaneous, up to 1.8 mg daily). A generic liraglutide is now FDA-approved.
Orforglipron
- Foundayo — chronic weight management (oral tablet, daily). The first oral non-peptide GLP-1 RA, FDA-approved April 2026.
Clinical relevance: insurance plans generally cover the brand under its FDA-approved indication and not the off-label use. Off-label prescribing of Ozempic for weight loss (or Mounjaro for weight loss) is legal but typically not insurance-covered. See our Cigna PA guide and Aetna PA guide for verbatim payer policy quotes.
Cost and access
Brand-name GLP-1 list prices range from ~$300/month (NovoCare Wegovy pen self-pay) to ~$1,300/month (full list), with significant variability by manufacturer self-pay program, insurance copay savings card, and channel (pharmacy, telehealth, Costco / Sam's Club / Amazon Pharmacy / LillyDirect / NovoCare). Compounded semaglutide and tirzepatide remain available through 503A pharmacies for cash pay typically $99–$400/month, though the FDA's enforcement-discretion grace period for compounded semaglutide ended February 2025. See our live GLP-1 pricing index for current channel-by-channel cash and insured pricing.
What's next: the GLP-1 pipeline
Several investigational GLP-1, dual-agonist, and triple-agonist drugs are in late-stage clinical trials but are not yet FDA-approved. The most-watched are retatrutide (Eli Lilly triple agonist), CagriSema (Novo Nordisk cagrilintide + semaglutide), MariTide (maridebart cafraglutide, Amgen), survodutide (Boehringer Ingelheim & Zealand Pharma), and ecnoglutide (Sciwind). For trial-by-trial NCT IDs, primary completion dates, and verified topline results, see our GLP-1 Pipeline Tracker (2026). For the FDA-approved landscape, see our FDA-approved weight-loss medications hub or our retatrutide evidence article for the deep dive on the strongest weight-loss readout to date.