The one study that counted them found fewer, not more. Deep vein thrombosis at 90 days ran 1.6% against 3.0% in matched hip-replacement patients [1]. That is a relative risk of 0.53, 95% CI 0.31 to 0.89, p = 0.014. The absolute gap is 1.4 percentage points. It is reassurance, not a reason to buy anything. The wound side of the same question is in what happens to a surgical wound.
The hip replacement cohort
Adults having a first hip replacement between 2003 and 2023 were pulled from a claims database. Three or more GLP-1 prescriptions in the prior year counted as exposed. Matching on demographics, conditions and lab values left 1,262 patients per side.
Two ninety-day outcomes separated. Clots ran 1.6% against 3.0%. Readmission ran 1.1% against 2.8%, a relative risk of 0.40, 95% CI 0.22 to 0.71, p = 0.001.
Those rates come to roughly 20 clots against 38. The paper does not print the counts. That is arithmetic from its own percentages, and 18 events is a thin margin.
Most of the study found nothing
Revision survival at five years was 94.6% against 95.5%, p = 0.674. Joint infection was 94.7% against 94.4%, p = 0.465. Other ninety-day outcomes did not separate either.
That flatness is the useful part. The reason people worry about a GLP-1 before an operation is delayed stomach emptying under anesthesia. This cohort did not find worse outcomes. The timing question is handled in whether you have to stop before surgery.
Heart surgery: four trials, 446 patients
Four randomized trials of liraglutide around cardiac surgery were pooled [2]. Thirty-day mortality came out at 0.42, interval 0.06 to 2.81. That rests on four deaths across both arms.
Any complication ran 0.92, interval 0.74 to 1.14. Cardiac events ran 1.08. Hypoglycemia ran 0.85, interval 0.34 to 2.13. Nausea and vomiting came out at 3.01, interval 0.26 to 35.27.
An interval reaching 35 is not a result. None of those numbers rules anything in or out. It is the difference between finding no effect and failing to look hard enough to see one.
Spinal fusion: no complication difference either
A claims analysis matched 425 semaglutide users against 2,514 controls having anterior lumbar interbody fusion [3]. Complication rates did not differ at 90 days or at two years. Users stayed 0.6 days less.
The cost fields moved a long way. Same-day surgical costs ran roughly $10,400 lower and 90-day costs roughly $9,700 lower. Complications were identical, so a smoother recovery did not buy that. Claims amounts are billed or reimbursed sums, not what anyone paid. That gap is tracked in what a GLP-1 saves the system.
Who is in the exposed group
Three filled prescriptions in a year. That is a filter, not a randomization. It selects people who tolerated the drug, afforded it, and kept going.
Most buyers do not, as the refill records in how long people stay on a GLP-1 show. Whatever makes someone a persistent filler probably also makes them a better surgical patient. Matching on database codes cannot see that.
What a buyer takes from this
Nothing to act on. The clot finding is a single moved endpoint among many. The complication nulls are the sturdier half, and they say the operation looks the same.
What one prevented event is worth is a separate calculation, set out in the cost per event prevented. Nobody should read a surgical benefit into a monthly price.