# Do GLP-1 Drugs Affect Spinal Fusion Surgery? It Depends on the Operation A review of twelve cohorts on GLP-1 drugs and cervical spine fusion found procedure-specific associations running in opposite directions | and overlapping source databases. Publisher: This GLP Editorial Team Canonical: https://thisglp.com/research/do-glp1-drugs-affect-spinal-fusion-surgery Updated: 2026-09-17 Published: 2026-09-16 [← Research](https://thisglp.com/research) Evidence # Do GLP-1 Drugs Affect Spinal Fusion Surgery? It Depends on the Operation These drugs look protective in one database, neutral in another and harmful in a third. Pooling it all gives an interval from 0.35 to 4.70. That is not an answer. It is a warning. [This GLP Editorial Team](https://thisglp.com/about)September 20268 min readUpdated September 2026 Odds of failed fusion, by operation · ACDF — one database · ACDF — another database · posterior fusion · everything pooled · 1.0 · The pooled row is what happens when you average studies that disagree this much **Research, not medical advice.** This GLP is independent and educational. Nothing here is a substitute for individualized care from a licensed clinician, and reading it creates no doctor–patient relationship. Talk to your own provider before starting, stopping, or changing any medication, peptide, or therapy. See our [methodology](https://thisglp.com/methodology) and [terms](https://thisglp.com/terms). ## Key takeaways - Twelve retrospective cohorts published in 2025 and 2026 looked at GLP-1 use and failed fusion after cervical spine surgery. - For anterior fusion, one large database gave OR 0.52, 95% CI 0.40 to 0.67, and another gave a neutral 0.86, 95% CI 0.56 to 1.32. - A semaglutide-specific posterior fusion cohort gave OR 4.79, 95% CI 3.11 to 7.37 — the opposite direction. - Pooling everything produced OR 1.28 with a 95% CI of 0.35 to 4.70 and heterogeneity of 97.3%. - Several of the twelve studies query overlapping databases, so they are not twelve independent samples. Both ways, depending on which operation. Take anterior cervical fusion first. One large database put failed fusion lower among GLP-1 users, at OR 0.52 (95% CI 0.40 to 0.67)[\[1\]](https://thisglp.com/research/do-glp1-drugs-affect-spinal-fusion-surgery#ref-1). A semaglutide-specific posterior fusion cohort found the opposite, at OR 4.79 (95% CI 3.11 to 7.37). Pooling everything gives an interval from 0.35 to 4.70, which is not a finding. The question is adjacent to [whether to pause them around an operation](https://thisglp.com/research/glp1-before-surgery) and separate from it. ## What was gathered Twelve retrospective cohorts, all published in 2025 or 2026. All cover GLP-1 exposure and outcomes after cervical fusion. Five databases were searched to June 2026. The primary outcome was pseudarthrosis, which is the fusion failing to knit. Take anterior cervical discectomy and fusion first. One large claims network put the odds of failed fusion lower among GLP-1 users, at OR 0.52, 95% CI 0.40 to 0.67. An independent estimate from a different network was neutral, at OR 0.86, 95% CI 0.56 to 1.32. The anterior subgroup as a whole came to 0.65, 95% CI 0.40 to 1.06, with heterogeneity of 74.5%. A semaglutide-specific posterior cervical fusion cohort went the other way entirely. Failed fusion at two years came in at OR 4.79, 95% CI 3.11 to 7.37. A dysphagia signal ran alongside it. The pooled number is the proof, not the answer Averaging all of it gives OR 1.28, 95% CI 0.35 to 4.70, with heterogeneity of 97.3%. That interval runs from a two-thirds reduction in failed fusions to a near-fivefold increase. It is not a finding about anything. The authors compute it and then reject the class-wide interpretation it invites, concluding that the associations are procedure-specific. A pooled estimate this wide is evidence that the studies should not have been pooled. ## Twelve studies, fewer than twelve samples This is the part worth carrying away. Several of the included cohorts query the same commercial claims networks. The same patient can appear in more than one apparently independent study. A reader counting twelve papers may be looking at far fewer distinct groups of people. The authors prespecified how to handle double counting. They used non-overlapping estimates for the primary synthesis. That is careful and it is rare, because most reviews in this literature simply count the papers. Large shared claims networks make the problem worse each year, and it affects [every study built on the same data](https://thisglp.com/research/semaglutide-fractures-diabetes-only). ## Why the direction might genuinely differ Anterior and posterior cervical fusion are different operations with different biology and different failure modes. A drug may affect one and not the other, or affect them oppositely. The authors take that position explicitly. The posterior finding may also reflect who gets a posterior fusion. That is generally more complex disease, more levels, more comorbidity. One cohort in one procedure is thin ground for a fourfold estimate. The review classes all of this as hypothesis-generating rather than actionable. The distance between [a pooled figure and a patient](https://thisglp.com/research/glp1-weight-loss-pooled-average) is rarely this visible. ## What the dose evidence adds One study sorted patients by prescription strength rather than by exposure [\[2\]](https://thisglp.com/research/do-glp1-drugs-affect-spinal-fusion-surgery#ref-2). It set high-dose GLP-1 use against standard-dose use before neck fusion surgery. After matching, the two dose groups held together on readmission, emergency visits, complications and failed fusion. Both dose groups had less failed fusion than matched non-users. The higher dose added nothing on top. That is an absence of an obvious dose penalty, not a demonstration that no difference exists. This site reads it in [twice the dose, the same recovery](https://thisglp.com/research/glp1-neck-fusion-high-dose). The wider surgical picture is in [what a GLP-1 does to surgery outcomes](https://thisglp.com/research/does-a-glp1-affect-surgery-outcomes). ## What it means before an operation That the question is live and unsettled, and that your surgeon should be told you are taking one of these drugs. Whether to pause it around surgery is a separate question, and the evidence there is mostly about anesthesia rather than about bone. No seller on this roster asks whether you have surgery scheduled. None would know what to do with the answer. [the census of what goes unasked](https://thisglp.com/tools/questions-they-leave-open) counts how much a prescription arrives without. Anybody facing a fusion should raise it with the surgeon who will do it. ## Frequently asked Do these drugs help or harm spinal fusion? Both answers appear in the evidence. Anterior fusion estimates ran from OR 0.52 to a neutral 0.86, while a posterior fusion cohort found OR 4.79 for failed fusion. The authors conclude the associations are procedure-specific and hypothesis-generating. What does the pooled estimate say? OR 1.28 with a 95% CI of 0.35 to 4.70 and heterogeneity of 97.3%. That range covers a large reduction and a near-fivefold increase, which means the studies should not be pooled rather than that the answer is neutral. Why does it matter that databases overlap? Because the same patient can appear in several apparently independent studies. Counting twelve papers can mean far fewer distinct groups of people, and this review prespecified how to handle that. Should I stop before spine surgery? That is a question for your surgeon, and this evidence does not answer it. Pausing around surgery is a separate issue, mostly concerning anesthesia rather than bone healing. ## Sources 1. \[1\] Yu X, et al. (2026). GLP-1 receptor agonists and outcomes after cervical spine fusion: a systematic review, meta-analysis, and evidence map of real-world evidence European Spine Journal. [PMID 42635669](https://pubmed.ncbi.nlm.nih.gov/42635669/) 2. \[2\] Stirpe C, et al. (2026). Impact of GLP-1 Dose Intensity on Perioperative and Long-Term Fusion Outcomes Following ACDF The Spine Journal. [PMID 42705550](https://pubmed.ncbi.nlm.nih.gov/42705550/) ## Where to get it ### Best GLP-1 injections Every injectable seller we can verify, with the price each one publishes and an honest read of what the trials measured. [Compare providers →](https://thisglp.com/best/compounded-semaglutide) ## More in Evidence - [ 150 minutes · Weekly activity goal · 2 days · Muscle strengthening · Adapt · Symptoms and ability ### Exercise on Ozempic: Building Strength Without Ignoring Symptoms ](https://thisglp.com/research/exercise-on-ozempic) - [ STEP 1, semaglutide 2.4 mg vs placebo, % change at 68 weeks · LDL cholesterol · −2.5% vs +1.3% · Total cholesterol · −3.3% vs +0.1% · HDL cholesterol · +5.2% vs +1.4% · Triglycerides · −21.9% vs −7.3% · Wegovy label, Table 13. Adults without diabetes. 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