GLP-1-Based Therapies for Diabetes, Obesity and Beyond: A Comprehensive Review

Bottom line: GLP-1-based peptide therapies have expanded far beyond glucose control — they now represent a platform technology for obesity, cardiovascular protection, liver disease, and potentially neurodegeneration, with next-generation multi-agonists poised to push efficacy even further.

Glucagon-like peptide-1 (GLP-1) is a 30-amino-acid incretin hormone released from intestinal L-cells after food intake. It stimulates insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite via central nervous system signaling. Synthetic GLP-1 receptor agonists engineered for prolonged half-life — most notably semaglutide and tirzepatide — have become among the most prescribed medications worldwide.

Scope of the Review

Published in Nature Reviews Drug Discovery (PMID: 40281304), this comprehensive review by Daniel J. Drucker profiles the entire GLP-1 therapeutic class, covering mechanism of action, established clinical evidence, and the rapidly expanding pipeline.¹

Key Themes

Established efficacy beyond glucose: Semaglutide reduced major adverse cardiovascular events (MACE) by 20% in the SELECT trial (HR 0.80, 95% CI 0.72–0.90, p < 0.001) in patients with obesity but without diabetes — establishing a cardiovascular indication independent of glycemic control. Tirzepatide demonstrated a 13% MACE reduction versus dulaglutide in SURPASS-CVOT (HR 0.87, 95% CI 0.79–0.96).¹

MASH and liver disease: Semaglutide 2.4 mg achieved MASH resolution without worsening fibrosis in 59% of patients versus 17% for placebo in a phase 2b study. Survodutide, a GLP-1/glucagon dual agonist, showed even higher MASH resolution rates (up to 83%) and is advancing in phase 3.¹

Next-generation multi-agonists: Retatrutide (GIP/GLP-1/glucagon triple agonist) achieved 24.2% mean weight loss at 48 weeks in phase 2, the highest ever reported for a pharmacological agent. Multiple phase 3 trials are underway. Amycretin (GLP-1/amylin) and CagriSema (semaglutide + cagrilintide) represent alternative multi-target strategies.¹

Oral and non-peptide approaches: Orforglipron, a non-peptide oral GLP-1 agonist, reached phase 3 with weight loss of approximately 14.7% at 36 weeks. Oral semaglutide 50 mg (Rybelsus next-generation) is also advancing, potentially eliminating the need for injections.¹

Emerging non-metabolic indications: The review catalogues active clinical trials in Alzheimer's disease, Parkinson's disease, substance use disorders (alcohol, opioids), obstructive sleep apnea, and polycystic kidney disease — reflecting GLP-1 receptor expression throughout the brain and kidneys.¹

Why This Matters

This review arrives at a pivotal moment: GLP-1 agonists have become the fastest-growing drug class globally, with combined annual revenues exceeding $50 billion. The question is no longer whether these peptides work for metabolism, but how far their therapeutic reach extends. Drucker's synthesis provides the most authoritative roadmap available.

Clinical implication: Clinicians should view GLP-1 receptor agonists not as diabetes drugs with weight-loss benefits, but as multi-system metabolic therapies. Expect label expansions for MASH, heart failure, and CKD within the next 2–3 years, and monitor emerging neurological trial data closely.

References

1. Drucker DJ. GLP-1-based therapies for diabetes, obesity and beyond. Nature Reviews Drug Discovery. 2025 Apr 25. PMID: 40281304. DOI: 10.1038/s41573-025-01183-8