Science

Latest GLP-1 Research in 2026: Key Findings to Know

GLP-1 Companion · 10 min read

The pace of GLP-1 research accelerated dramatically between 2024 and 2026. New head-to-head efficacy data, expanded indications beyond weight loss, fully oral formulations reaching approval, and next-generation molecules with even greater efficacy have all arrived in a compressed period. This article summarizes the most clinically important findings for patients and clinicians following the field.

SURMOUNT-5: Tirzepatide vs Semaglutide Head-to-Head

The SURMOUNT-5 trial, published in the New England Journal of Medicine in early 2025, was the first randomized head-to-head comparison of tirzepatide (Zepbound) and semaglutide 2.4 mg (Wegovy) for weight management in adults with obesity or overweight without diabetes. The results confirmed and quantified what many clinicians had observed in clinical practice: tirzepatide produces substantially greater weight loss than semaglutide.

• Tirzepatide group: average weight loss of approximately 20.2 percent of body weight at 72 weeks
• Semaglutide 2.4 mg group: average weight loss of approximately 13.7 percent at 72 weeks
• Relative difference: tirzepatide produced approximately 47 percent more weight loss than semaglutide
• Achieving 25% or more weight loss: 32% of tirzepatide patients vs 7% of semaglutide patients
• Both drugs showed good tolerability; GI side effect rates were comparable

SURMOUNT-5 is important because it provides randomized evidence — not just cross-trial comparisons — confirming tirzepatide's efficacy advantage. The dual GIP/GLP-1 mechanism of tirzepatide appears to produce synergistic effects on appetite suppression and fat metabolism that exceed what GLP-1 agonism alone achieves.

SOUL Trial: Oral Semaglutide and Cardiovascular Risk

The SOUL trial evaluated oral semaglutide (Rybelsus, 14 mg/day) in patients with type 2 diabetes and high cardiovascular risk. Results published in 2025 demonstrated that oral semaglutide reduced the risk of major adverse cardiovascular events, extending the cardiovascular protection seen with injectable semaglutide to the oral formulation. This was a meaningful finding because oral administration substantially lowers the barrier for patients who are needle-averse or otherwise reluctant to start injectable therapy. The SOUL data support oral semaglutide as a cardiovascular risk-reduction option in type 2 diabetes, though the approved dose for diabetes management (14 mg) is distinct from higher oral semaglutide doses under development for obesity.

FLOW Trial: Kidney Protection in Type 2 Diabetes and CKD

The FLOW trial evaluated semaglutide 1.0 mg in patients with type 2 diabetes and chronic kidney disease (CKD stages 2-4) and was stopped early in 2024 due to overwhelming efficacy. Full results, published and presented in 2024-2025, showed that semaglutide significantly reduced the risk of kidney disease progression, kidney failure requiring dialysis or transplant, cardiovascular death, and all-cause death in this high-risk population.

• Primary kidney composite endpoint: 24% relative risk reduction with semaglutide vs placebo
• Cardiovascular death: significant reduction observed
• The benefit appeared to be partly independent of glucose lowering, suggesting direct renoprotective effects
• FDA approval for kidney disease protection in adults with type 2 diabetes and CKD was granted, adding a renal indication to semaglutide's label

Semaglutide Approved for MASH (Metabolic Liver Disease)

In August 2025, the FDA approved semaglutide for the treatment of metabolic dysfunction-associated steatohepatitis (MASH) with moderate to advanced liver fibrosis. The ESSENCE trial showed that semaglutide 2.4 mg produced MASH resolution without worsening of fibrosis in approximately 62 percent of patients compared to 34 percent receiving placebo. Liver fibrosis improvement was observed in 37 percent of the semaglutide group. This approval made semaglutide the first GLP-1 agent — and one of very few medications — approved specifically for MASH, a condition affecting an estimated 5 to 6 percent of the global adult population and a leading cause of liver transplantation.

Orforglipron: First FDA-Approved Oral Small-Molecule GLP-1

Orforglipron received FDA approval in April 2026, marking a significant milestone: it is the first non-peptide, small-molecule oral GLP-1 receptor agonist approved in the United States. Unlike oral semaglutide (Rybelsus), which is a peptide requiring strict fasting conditions and specific administration protocols to achieve adequate absorption, orforglipron is a small molecule that can be taken without regard to food. Clinical trials demonstrated weight loss of approximately 9 to 10 percent over 36 weeks, with cardiovascular outcome data from the ATTAIN trials supporting its use in type 2 diabetes. Orforglipron may substantially improve accessibility for patients who cannot or will not inject and who find the oral semaglutide dosing protocol burdensome.

Retatrutide: Phase 3 Results Push the Efficacy Ceiling

Retatrutide is a triple agonist targeting GLP-1, GIP, and glucagon receptors simultaneously. The TRIUMPH-4 Phase 3 trial reported a mean weight loss of 28.7 percent at 48 weeks on the highest dose (12 mg weekly) — the highest weight loss ever reported for a pharmacological treatment in a controlled clinical trial. To put this in context, surgical sleeve gastrectomy produces approximately 25 to 30 percent excess weight loss in comparable timeframes. If FDA review proceeds on schedule, retatrutide could reach approval in late 2026 or 2027, potentially redefining the upper boundary of what medication-based obesity treatment can achieve.

Alcohol Use Disorder: Promising RCT Data

A randomized controlled trial published in February 2025 provided the first high-quality evidence that semaglutide reduces alcohol consumption in patients with alcohol use disorder (AUD). Participants on semaglutide showed significant reductions in heavy drinking days, total drinks per week, and alcohol craving scores compared to placebo. This builds on preclinical and observational data suggesting GLP-1 receptors in the brain's reward circuitry mediate addictive behavior, not just appetite. Several GLP-1 medications are now in Phase 2 or Phase 3 trials for AUD, nicotine dependence, and opioid use disorder.

Alzheimer's Disease: Research Progressing

Two large Phase 3 trials evaluating GLP-1 agonists for Alzheimer's disease prevention and treatment are ongoing as of April 2026. The EVOKE trial (semaglutide vs placebo in early Alzheimer's disease) and a tirzepatide trial in patients with metabolic risk factors for cognitive decline are both actively enrolling or in follow-up. Epidemiological data from large cohorts has consistently shown lower rates of dementia in patients on GLP-1 medications, and brain imaging studies have demonstrated reduced neuroinflammation and improved hippocampal function. Results from these trials are expected in 2027 to 2028.

Other Active Research Areas

• Heart failure with preserved ejection fraction (HFpEF): STEP-HFpEF trial showed semaglutide significantly reduced symptoms and improved exercise tolerance in obese patients with HFpEF
• Obstructive sleep apnea: Tirzepatide reduced AHI (apnea-hypopnea index) by approximately 55-63% in the SURMOUNT-OSA trial
• Polycystic ovary syndrome (PCOS): Multiple trials exploring improvements in hormonal markers, menstrual regularity, and fertility outcomes
• Psoriasis and inflammatory skin conditions: Anti-inflammatory GLP-1 effects being studied in dermatology contexts
• Depression and anxiety: Observational and mechanistic data suggesting mood improvements independent of weight loss
• Weekly oral semaglutide at higher doses for obesity: Phase 3 trials ongoing with doses up to 50 mg weekly

The Bottom Line

The GLP-1 research landscape in 2026 is arguably the most productive period in the history of obesity medicine. Head-to-head efficacy data confirms tirzepatide's superiority over semaglutide for weight loss. Oral options are expanding with orforglipron's approval. New indications — kidney disease, MASH, cardiovascular risk reduction, potentially Alzheimer's disease — are repositioning GLP-1 medications as broadly acting cardiometabolic and neuroprotective agents, not simply weight-loss drugs. The pipeline continues to advance, with retatrutide potentially pushing efficacy to near-surgical levels.

Sources

• Belsham et al. (2026). Genetic predictors of GLP1 receptor agonist weight loss and side effects. Nature.
• Lincoff et al. (2023). Semaglutide and Cardiovascular Outcomes in Obesity. NEJM.