GLP-1 Drugs: The Hormone, the Class, the Approved List

Last reviewed: May 12, 2026 Last updated: May 12, 2026

Written by: Jay Hastings , CEO of PlexusDx

Jay Hastings is the CEO of PlexusDx, a precision health company focused on genetic testing, blood biomarker insights, and personalized wellness recommendations. He has more than 20 years of experience across healthcare innovation, genomics, laboratory operations, healthcare investing, and strategic finance. His work has included scaling healthcare startups, leading CLIA lab integrations, and helping expand consumer access to precision health tools.

Medically reviewed by: Jayden Lee, PharmD, EMBA

Jayden Lee, PharmD, EMBA, is the PlexusDx Medical Science Liaison with a PharmD and MBA specializing in pharmacogenomics and clinical product development, with a proven ability to bridge the gap between genomic research and practical patient outcomes. Dr. Lee has more than 10 years of professional experience in clinical pharmacy, academia, and research.

Welcome to the PlexusDx Education Hub, where metabolic science, GLP-1 pathway biology, and the genetics that shape each person’s response are unpacked in plain language. Browse the full Peptides & GLP-1 library.

"GLP-1 drugs" is a search for the whole picture — what the hormone is, how the medicines built from it work, and which compounds actually exist. The class starts with a natural gut hormone and extends into a growing roster of engineered medications. This article walks that arc from biology to product list, then to the genetics beneath it.

The hormone at the root

GLP-1 — glucagon-like peptide-1 — is an incretin hormone released by L-cells of the small intestine after you eat. Native GLP-1 is a 30- to 31-amino-acid peptide that stimulates glucose-dependent insulin secretion from pancreatic beta cells, suppresses glucagon, slows gastric emptying, and engages satiety circuits in the hypothalamus. Its natural half-life is very short — roughly two minutes — because the enzyme DPP-4 breaks it down almost immediately.

How the drugs re-engineer it

GLP-1 receptor agonist medications are designed to resist DPP-4 degradation, stretching half-life from minutes to days or even weeks. They bind the same GLP-1 receptor as the native hormone, reproducing its downstream effects on insulin secretion, glucagon suppression, gastric emptying, and satiety. Tirzepatide-based compounds add agonism at the GIP receptor, a related incretin receptor and one of the key molecular distinctions in the class as of April 2026.

The FDA-approved roster

As of April 2026 the approved class includes exenatide (Byetta, 2005; Bydureon), liraglutide (Victoza, 2010; Saxenda, 2014), dulaglutide (Trulicity, 2014), semaglutide (Ozempic, 2017; Rybelsus, 2019; Wegovy, 2021), and tirzepatide (Mounjaro, 2022; Zepbound, 2023; Zepbound expanded to OSA, 2024). Late-stage investigational agents include retatrutide, a GIP/GLP-1/glucagon triple agonist, and orforglipron, an oral non-peptide small-molecule GLP-1 receptor agonist. Retatrutide remains investigational and is not sold by PlexusDx.

Agonists versus inhibitors

A common mix-up: GLP-1 receptor agonists activate the receptor and reproduce the hormone's effects. There is no widely used clinical class called "GLP-1 inhibitors." DPP-4 inhibitors are a separate category — they slow the breakdown of native GLP-1 but do not activate the receptor directly.

From injections toward oral options

One of the clearer trends in the drug list is the slow expansion of how these medicines are delivered. For most of the class's history, subcutaneous injection has been the standard route, with dosing schedules ranging from daily to weekly depending on the compound. As of April 2026, Rybelsus remains the only FDA-approved oral tablet, a reminder that swallowing a GLP-1 is still the exception rather than the rule among branded products.

The investigational pipeline hints at where this may head. Orforglipron, an oral non-peptide small-molecule GLP-1 receptor agonist, is in late-stage development precisely because a durable, easy-to-take oral form would remove a real barrier for many people. It is not approved, and nothing here should be read as an endorsement of an investigational agent — but it illustrates why "the GLP-1 drug list" is a moving target. Reading it as a snapshot in time, rather than a fixed roster, keeps expectations aligned with a field that is still evolving.

For that reason, the most reliable roster is always the current FDA-approved list, cross-checked against each product's own labeling rather than secondhand summaries that may lag behind approvals.

The genetics sitting upstream

Because these drugs act through a receptor system with natural variation, the metabolic starting point differs by person. GLP1R — the receptor gene itself — influences receptor density and incretin-signaling efficiency and sits closest to the mechanism, while FTO, MC4R, and TCF7L2 shape adjacent appetite, satiety, and insulin biology. The PlexusDx Precision Peptide Genetic Test maps 14 pathways, 49 peptides, 150+ genetic insights — 503A-era, pathway-level education that never predicts response. PlexusDx offers GLP-1 receptor agonists through its Weight Management Protocols, with the genetic report as the test before you invest first step.

Frequently Asked Questions

What does GLP-1 stand for?

GLP-1 stands for glucagon-like peptide-1, an incretin hormone released by intestinal L-cells after eating. It stimulates glucose-dependent insulin release, slows gastric emptying, and signals satiety to the brain. The GLP-1 receptor agonist drug class is engineered to reproduce those effects in a longer-lasting form.

Why do native GLP-1 and the drugs last such different times?

Native GLP-1 has a half-life of about two minutes because DPP-4 degrades it quickly. GLP-1 receptor agonist medications are engineered to resist DPP-4, extending half-life to days or weeks while binding the same receptor. That durability is central to how the drug class works.

Which GLP-1 drugs are FDA-approved?

As of April 2026 the class includes exenatide, liraglutide, dulaglutide, semaglutide, and tirzepatide across various brands. Retatrutide and orforglipron are investigational and not yet approved. Retatrutide is not sold by PlexusDx. Each approved product's indications live in its own FDA label.

Does genetic testing tell me which GLP-1 drug to take?

No. The Precision Peptide Genetic Test does not predict which GLP-1 medication suits any individual. It reads pathway-level variants such as FTO and MC4R, and TCF7L2 that describe baseline GLP-1 biology — educational context for the broader protocol conversation with a healthcare provider.

Keep exploring the PlexusDx Education Hub for more grounded, provider-minded answers. Return to the Peptides & GLP-1 library.

Medical and Editorial Standards

Medical review process: This article was reviewed for medical accuracy, scientific clarity, evidence alignment, and appropriate discussion of genetics, medications, supplements, biomarkers, and health-related claims.

Sources and evidence: PlexusDx educational content is developed using peer-reviewed research, clinical literature, reputable medical references, and, where applicable, public health or regulatory guidance. References are included at the end of the article when scientific, medical, or health-related claims are discussed.

Commercial transparency: PlexusDx offers genetic testing, blood biomarker testing, personalized supplement recommendations, and related precision wellness services. Product mentions are intended to help readers understand available options and should not be interpreted as medical advice.

Important disclaimer: PlexusDx educational content is for informational purposes only and should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making decisions about medications, supplements, genetic testing, lab testing, or health-related care.