GLP-1 Therapies Newsletter
Issue #24February 16, 20267 studies

Tirzepatide beats semaglutide for weight loss by 6.1% in head-to-head comparison

GLP-1 drugs are having a moment, but this week's research reveals some surprising differences between the leading options—and some unexpected risks that patients should know about.

🏆 Tirzepatide outperforms semaglutide in massive weight loss showdown

  • Analysis of 28 trials with 34,367 participants found tirzepatide reduced weight by 6.1% more than semaglutide (at maximum doses of 15mg vs 2.4mg)

  • Tirzepatide also beat semaglutide on absolute weight loss (4.55 kg more), BMI reduction (1.71 kg/m² more), and blood sugar control (0.33% better HbA1c)

  • The dual-hormone approach (targeting both GLP-1 and GIP receptors) appears to give tirzepatide the edge over single-hormone semaglutide

Why it matters: This head-to-head comparison provides the clearest evidence yet that not all GLP-1-class drugs are created equal—the newer dual-receptor approach may be worth the extra cost for patients seeking maximum weight loss.

Top 20% journal 🔗 Journal of diabetes 🗓️ Feb 10

Key Findings

👁️ Semaglutide linked to 2x higher risk of rare vision loss

  • Among 102,361 US veterans with diabetes, those starting semaglutide had 2.33 times higher risk of nonarteritic anterior ischemic optic neuropathy (NAION) compared to SGLT2 inhibitor users

  • The absolute risk was still low: 0.29% for semaglutide users vs 0.13% for the comparison group over 2.1 years

  • NAION causes sudden, painless vision loss that's typically permanent

💡 Patients should be aware of this rare but serious risk when considering semaglutide treatment.
🥉 Top 5% journal 🔗 JAMA ophthalmology 🗓️ Feb 12

🧠 Semaglutide may protect against brain aneurysm ruptures

  • Study of 24,776 diabetes patients with unruptured brain aneurysms found 38% lower risk of rupture at 3 years for those on GLP-1 drugs

  • The protective effect remained significant at 5 years (35% risk reduction) after accounting for other health factors

  • Brain aneurysm rupture leads to subarachnoid hemorrhage, which has high mortality rates

💡 GLP-1 drugs may have unexpected vascular protective effects beyond their known heart benefits.
Top 30% journal 🔗 J Clin Neurosci 🗓️ Feb 11

🦴 GLP-1 drugs associated with 11% higher fracture risk in older adults

  • Analysis of 46,177 adults over 65 with diabetes found those starting GLP-1 drugs had modestly increased risk of fragility fractures

  • The increased risk was small but statistically significant after accounting for other factors

  • Study followed patients for median of 34.7 months, during which 8.8% experienced fractures

💡 The bone health effects of rapid weight loss from GLP-1 drugs may need closer monitoring in older patients.

🫀 Semaglutide improves atrial fibrillation outcomes after heart procedures

  • Among 362 obese patients undergoing catheter ablation for atrial fibrillation, those on semaglutide had 80.2% freedom from recurrence vs 65.2% for controls at 18 months

  • Semaglutide users lost significantly more weight (11.8 kg vs 1.9 kg) and had 48% lower risk of arrhythmia recurrence

  • Treatment persistence was high at 92.6% with minimal side effects

💡 GLP-1 drugs may serve as valuable add-on therapy for obese patients with heart rhythm disorders.
🥉 Top 5% journal 🔗 Europace 🗓️ Feb 10

🔬 New oral GLP-1 drug shows promise without injections

  • Orforglipron, a pill-form GLP-1 drug, demonstrated significant reductions in blood sugar, weight, and cardiovascular risk markers in clinical trials

  • Unlike current oral semaglutide (which still requires special dosing), this nonpeptide drug could improve convenience and adherence

  • Phase 1-3 trials showed acceptable safety profile with potent receptor engagement

💡 Oral GLP-1 options could make these powerful metabolic drugs accessible to patients who can't or won't use injections.

🏥 GLP-1 users have fewer surgical complications across weight categories

  • Study of 72,578 procedures in diabetic patients found those on GLP-1 drugs had 26-60% lower risk of wound problems and 18-45% fewer readmissions

  • Benefits were seen across all weight categories, with the biggest improvements in morbidly obese patients

  • This occurred despite GLP-1 users having higher baseline blood sugar levels

💡 GLP-1 drugs may improve surgical outcomes through mechanisms beyond just weight loss and blood sugar control.
Top 50% journal 🔗 Annals of plastic surgery 🗓️ Feb 13

Implications

This week's research reveals GLP-1 drugs as a double-edged sword: while tirzepatide emerges as the weight-loss champion and these drugs show unexpected benefits for heart rhythms and surgical outcomes, new safety signals around vision loss and fractures remind us that even breakthrough medications require careful risk-benefit analysis.

Studies in this issue

Primary sources used for this newsletter.

  1. Comparing the Weight Loss Effects of Tirzepatide and Semaglutide
    main storyJournal of diabetes2026-02-10PMID 41664890
  2. Orforglipron: An oral drug that activates appetite and blood sugar control systems for obesity and type 2 diabetes
    key findingInternational journal of molecular sciences2026-02-13PMID 41683830
  3. GLP-1 receptor agonists and fracture risk in older adults with type 2 diabetes
    key findingThe Journal of clinical endocrinology and metabolism2026-02-10PMID 41665888
  4. Use of GLP-1 Diabetes Drugs Linked to Fewer Surgical Complications Across Different Body Weights
    key findingAnnals of plastic surgery2026-02-13PMID 41687055
  5. GLP-1 receptor drugs and the risk of aneurysm rupture in type 2 diabetes
    key findingJournal of clinical neuroscience : official journal of the Neurosurgical Society of Australasia2026-02-11PMID 41671787
  6. New Cases of Sudden Optic Nerve Damage Linked to Starting Semaglutide in US Veterans with Type 2 Diabetes
    key findingJAMA ophthalmology2026-02-12PMID 41678180
  7. Semaglutide added to catheter treatment for irregular heartbeats linked to obesity
    key findingEuropace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology2026-02-10PMID 41666150

Continue reading

All GLP-1 Therapies issues