A large September 2026 <a href="https://glp1place.com/tools/compound/glp-1/”>GLP-1 venous insufficiency study found that adults with obesity and chronic venous insufficiency who received GLP-1 therapy had lower observed rates of deep-vein thrombosis, pulmonary embolism, venous ulcers, soft-tissue infections, and death than statistically matched nonusers. The study included more than 24,000 matched participants and followed outcomes for up to three years. However, it was a retrospective analysis of electronic health records, not a randomized prevention trial. The findings point to a potentially important vascular signal, but they do not prove that semaglutide, tirzepatide, liraglutide, or another GLP-1 medicine prevents blood clots.
Published in the September 2026 issue of the Journal of Vascular Surgery: Venous and Lymphatic Disorders, the study examined people with substantial baseline vascular risk. Chronic venous insufficiency can cause leg swelling, skin changes, venous ulcers, recurrent infections, reduced mobility, and venous thromboembolic complications. Obesity can add metabolic, inflammatory, and mechanical risk factors. That makes the analysis relevant to both obesity medicine and vascular research.
The central question is whether the metabolic and weight-related effects linked with GLP-1 receptor agonists are also linked with fewer serious venous complications. This study makes that hypothesis more plausible, but does not prove it.
What the GLP-1 venous insufficiency study measured
Researchers from UCLA, Harbor-UCLA Medical Center, and the University of Southern California used the TriNetX US Collaborative Network to identify adults aged 40 years or older with obesity and chronic venous insufficiency between 2016 and 2025. The initial database included 138,853 eligible patients, including 12,874 who had received GLP-1 therapy.
Using propensity-score matching, a statistical method intended to make comparison groups more alike on measured characteristics, the investigators created two groups of 12,379 patients each. Matching accounted for age, race, sex, smoking history, body mass index, diabetes, medications, and other health conditions. Patients with previous deep-vein thrombosis or pulmonary embolism were excluded so the analysis could focus on newly recorded events after chronic venous insufficiency diagnosis.
The primary outcome was acute deep-vein thrombosis at one and three years. Secondary outcomes included pulmonary embolism, venous leg ulcers, soft-tissue infections, and all-cause mortality. The full publication is available through PubMed, including the study design, matching methods, reported hazard ratios, confidence intervals, and disclosures.
| Outcome | One-year association with GLP-1 therapy | Interpretation |
|---|---|---|
| Acute deep-vein thrombosis | HR 0.54; 95% CI 0.42–0.71 | Lower observed risk in the GLP-1 cohort |
| Pulmonary embolism | HR 0.43; 95% CI 0.27–0.66 | Lower observed risk in the GLP-1 cohort |
| Venous ulcers | HR 0.47; 95% CI 0.33–0.66 | Lower observed risk in the GLP-1 cohort |
| Soft-tissue infections | HR 0.61; 95% CI 0.52–0.72 | Lower observed risk in the GLP-1 cohort |
| Overall survival | 99% versus 94% at one year | Higher recorded survival in the GLP-1 cohort |
Hazard ratios below 1.0 indicate that the GLP-1-treated group had fewer recorded events during follow-up than the matched comparison group. They do not mean every individual’s risk falls by the same percentage, and they do not establish cause and effect.
Reported clot, ulcer, infection, and survival findings
At one year, GLP-1 therapy was associated with a 46% lower relative hazard of acute DVT, a 57% lower relative hazard of pulmonary embolism, a 53% lower relative hazard of venous ulcers, and a 39% lower relative hazard of soft-tissue infections. The paper reported that these associations were still present at three-year follow-up.
One-year survival was 99.0% in the GLP-1 cohort and 94.0% in the non-GLP-1 cohort. At three years, reported survival was 95.0% and 86.0%, respectively. These differences are notable, but they also show why retrospective database findings require careful interpretation. Treatment selection may reflect factors that electronic records do not fully capture, including healthcare access, mobility, clinician engagement, adherence, disease severity, and overall care intensity.
For example, people receiving GLP-1 medicines may have had more health-system contact, earlier recognition of symptoms, better diabetes management, or a greater ability to follow care plans. Clinicians may also have avoided GLP-1 therapy in some frail or medically complex patients. Propensity-score matching can balance measured factors, but it cannot fully account for unmeasured differences.
The authors describe the results as associations and call for further study. That distinction matters: this is an important observational signal for future research, not evidence that GLP-1 medicines should be considered anticoagulants or established ulcer-prevention treatments.
Why chronic venous insufficiency changes the question
Chronic venous insufficiency occurs when veins in the lower limbs do not return blood efficiently toward the heart. Venous reflux, reduced calf-muscle pumping, increased venous pressure, edema, inflammation, and skin breakdown can interact over time. In advanced disease, persistent swelling, discoloration, fibrosis, and open venous ulcers can develop.
Obesity can complicate this process in several ways. Higher body mass may increase pressure in the lower extremities and reduce mobility. Adipose tissue is associated with inflammatory signaling, insulin resistance, endothelial dysfunction, and other factors relevant to vascular health. Less movement can further reduce the calf-muscle pump that helps blood return through the veins.
This population differs from the average participant in a cardiovascular-outcomes trial for diabetes or obesity. The question was not simply whether GLP-1 treatment affected glucose or body weight. It was whether GLP-1 exposure was associated with fewer later complications in people already living with chronic venous disease.
The outcomes extend beyond laboratory measures. Venous ulcers can require prolonged wound care and may be complicated by infection. Pulmonary embolism can lead to emergency care and may be life-threatening. If the survival association is independently confirmed, the clinical significance of this research question could extend beyond weight or glycemic outcomes.
How the findings fit with earlier GLP-1 clotting research
The new study does not settle the evidence on GLP-1 receptor agonists and venous thromboembolism. Earlier research has been mixed.
A 2025 systematic review and meta-analysis of 27 randomized controlled trials involving more than 84,000 participants found no statistically significant reduction in overall venous thromboembolism with GLP-1 receptor agonists, although pulmonary embolism was less frequent in treatment groups. It found no statistically significant difference in DVT. The analysis is available through PubMed.
A separate 2025 meta-analysis of 39 randomized trials reported a possible increase in DVT, particularly in longer cardiovascular-outcomes trials, while finding no significant association with pulmonary embolism. That analysis is indexed at PubMed. Differences in trial selection, event definitions, follow-up periods, statistical methods, and background therapies may help explain the differing results.
The September 2026 chronic venous insufficiency study differs from those randomized-trial syntheses in important ways:
- It focused on adults with obesity and diagnosed chronic venous insufficiency rather than a broad diabetes or obesity population.
- It used longitudinal real-world health-record data rather than randomized treatment assignment.
- It assessed venous ulcers and soft-tissue infections in addition to DVT and pulmonary embolism.
- It excluded people with prior DVT or pulmonary embolism.
- It evaluated one-year and three-year outcomes.
These differences may help explain why this cohort found a stronger protective association than earlier randomized-trial syntheses. They also mean the studies should not be treated as interchangeable evidence answering the same question.
Possible explanations for the observed association
The study was not designed to identify a mechanism, so these possible explanations are provisional rather than demonstrated.
Weight reduction and mechanical effects
Weight reduction may reduce mechanical pressure on the lower extremities, support mobility, and potentially improve the calf-muscle pump’s contribution to venous return. These changes could affect swelling, venous pressure, skin integrity, and physical activity. The database analysis cannot determine how much of the association was mediated by weight change or whether the groups experienced comparable weight changes.
Metabolic control
GLP-1 medicines, including semaglutide, liraglutide, and tirzepatide, can improve glucose regulation within their approved indications. Better metabolic control may be relevant to inflammation, endothelial function, blood pressure, and overall vascular risk. However, the study did not establish glucose improvement as the reason for its findings.
Inflammatory pathways
Obesity and chronic venous disease are associated with inflammatory signaling. Improvements in metabolic health could theoretically influence inflammatory burden, tissue integrity, or ulcer-related complications. This is biologically plausible, but the retrospective study did not directly demonstrate it.
Healthcare-contact and selection effects
People prescribed GLP-1 therapy may have more structured follow-up, medication review, monitoring, and management of coexisting conditions. These differences could contribute to earlier treatment of wounds or infections and better overall care. Residual confounding is therefore a central reason the study cannot establish a direct medication effect.
What the study does not show
The paper does not show that GLP-1 receptor agonists are anticoagulants. It does not show that they dissolve existing clots, replace established venous care, heal established ulcers, or prevent pulmonary embolism in every patient. It also does not establish whether one GLP-1 agent has a better vascular-outcome profile than another.
The investigators evaluated GLP-1 therapy as a class. The findings should not be used to claim that semaglutide, tirzepatide, liraglutide, or another individual medicine has a proven indication for chronic venous insufficiency. The publication also does not provide a treatment protocol, dosing recommendation, or basis for self-directed use.
For broader context, GLP1Place has previously reviewed emerging safety signals in semaglutide and liraglutide users in the 2026 GLP-1 safety study analysis. That post concerns a different dataset and different outcomes, so the two studies should not be combined into a single conclusion about overall GLP-1 safety.
Research and regulatory implications
The results could encourage researchers to include venous-disease outcomes in future obesity and metabolic studies. Many GLP-1 studies focus on body weight, glycemic measures, cardiovascular events, kidney disease, liver disease, sleep apnea, or body composition. Chronic venous insufficiency and venous-ulcer outcomes have received less attention.
If independently reproduced, future studies could evaluate objectively confirmed DVT, pulmonary embolism, ulcer healing time, ulcer recurrence, infection-related admissions, mobility, and validated quality-of-life measures. Detailed reporting of medication exposure, treatment duration, weight change, baseline ulcer severity, mobility, anticoagulant use, compression therapy, diabetes control, and healthcare use would help distinguish pharmacologic effects from care-pattern differences.
GLP-1 receptor agonists remain prescription medicines with product-specific approved indications, labeling, contraindications, warnings, and monitoring requirements. A real-world publication reporting an association does not create a new approved use. Regulatory claims of benefit require controlled evidence for a defined indication.
The FDA has also warned that unapproved GLP-1 products do not undergo the agency’s premarket review for safety, effectiveness, and quality. This research should therefore be presented as an observational finding about GLP-1 therapy in healthcare records, not as support for unapproved products or for changing established vascular treatment.
Bottom line
The September 2026 GLP-1 venous insufficiency study is a notable examination of whether obesity treatment may be associated with chronic venous disease outcomes. In a large matched cohort, GLP-1 therapy was associated with fewer recorded DVTs, pulmonary embolisms, venous ulcers, soft-tissue infections, and deaths at one and three years.
The pattern is clinically relevant and biologically plausible, but it is not definitive. Earlier randomized-trial analyses have reported conflicting venous-thromboembolism signals, and this observational study cannot fully rule out differences in treatment selection, healthcare access, mobility, weight change, or care intensity.
The measured conclusion is that GLP-1 therapy may be associated with better venous outcomes among adults with obesity and chronic venous insufficiency. Independent replication and prospective testing are needed before the association can support prevention or treatment claims.
Frequently Asked Questions
What did the 2026 GLP-1 venous insufficiency study find?
In a retrospective matched cohort of adults with obesity and chronic venous insufficiency, GLP-1 therapy was associated with lower one-year risks of acute DVT, pulmonary embolism, venous ulcers, and soft-tissue infections. Recorded survival was also higher in the GLP-1 group at one and three years.
Did the study prove that GLP-1 drugs prevent blood clots?
No. The study used observational electronic-health-record data. Statistical matching can reduce measured differences between groups, but it cannot eliminate confounding or prove that GLP-1 therapy caused the lower event rates.
Which GLP-1 drugs were studied?
The publication evaluated GLP-1 therapy as a class and did not establish separate vascular-outcome results for semaglutide, tirzepatide, liraglutide, or another individual agent. It should not be assumed that every GLP-1 medicine has identical effects.
How large was the study?
Researchers identified 138,853 adults with obesity and chronic venous insufficiency. After propensity-score matching, each comparison group included 12,379 participants.
What risk associations were reported?
At one year, hazard ratios were 0.54 for acute DVT, 0.43 for pulmonary embolism, 0.47 for venous ulcers, and 0.61 for soft-tissue infections. These are relative associations in a matched cohort, not guaranteed individual risk reductions.
How does this compare with earlier GLP-1 clotting research?
Earlier randomized-trial meta-analyses have been mixed. One found no statistically significant reduction in overall venous thromboembolism while reporting fewer pulmonary embolisms; another reported a possible DVT increase. The new cohort strengthens the research question but does not settle it.
Should GLP-1 medicines be used to prevent clots or venous ulcers?
No. This was not a prevention trial, and the findings do not establish a clot-prevention or ulcer-treatment indication. Medication decisions and suspected vascular symptoms require appropriate qualified clinical evaluation.