Preoperative GLP-1 Drug Use Does Not Compromise Bariatric Surgery Weight Loss Outcomes | Research

The takeaway

In 2,379 bariatric surgery patients, preoperative GLP-1 use was not associated with reduced postoperative weight loss (20.7% vs 22.0% TWL at 12 months, p=0.19), including in active-comparator diabetes subgroup.

No surgical penalty
Patients who used GLP-1 drugs before bariatric surgery achieved the same weight loss as non-users — preoperative GLP-1 doesn't compromise outcomes

What the researchers found

Preoperative GLP-1 use: %TWL at 12 months 20.7% vs 22.0% non-users (p=0.19). Diabetes active-comparator: 21.5% vs 23.1% (p=0.39). Pre-op BMI higher for GLP-1 users 12 months pre-op (47.0 vs 44.4) but similar at surgery (45.9 vs 46.1).

Why it matters

This evidence should reassure bariatric surgeons that patients who used GLP-1 drugs preoperatively will still achieve excellent surgical weight loss.

How the study worked

Retrospective statewide cohort (2020-2024) using health information exchange, 2,379 MBS patients (193 GLP-1 users), propensity-adjusted multivariable linear mixed-effects models.

What this study cannot tell us

Retrospective. 193 GLP-1 users (8.1%) is a small exposed group. 12-month follow-up. Cannot assess GLP-1 drug timing or dose.

How to read the evidence

Statewide multi-system cohort with active-comparator analysis. Larger and more rigorous than prior single-center studies.

When this study was published

Published in 2025.

The bigger picture

GLP-1 drugs and bariatric surgery are complementary, not competing. Preoperative GLP-1 use may actually help patients reach surgery at a better starting point.

Questions still open

Should GLP-1 drugs be standard preoperative preparation for bariatric surgery?
Do patients who continue GLP-1 post-surgery have better long-term outcomes?
Does preoperative GLP-1 use reduce perioperative complications?

Common questions

Will GLP-1 drugs hurt my weight loss after bariatric surgery?

No. This large study found patients who took GLP-1 drugs before surgery lost the same amount of weight as those who didn't. GLP-1 drugs may actually help patients prepare better for surgery.

Should I stop GLP-1 drugs before bariatric surgery?

This study doesn't support stopping based on weight loss concerns. Decisions about perioperative GLP-1 management should focus on aspiration risk, not weight loss outcomes.

Read the original research

Preoperative GLP-1 Receptor Agonist Use and Weight Loss Outcomes Following Bariatric Surgery.

Annals of surgery

View on PubMed ↗Publisher’s paper ↗

Citation

Holler, Emma; Samuels, Jason M; Stefanidis, Dimitrios; Yuce, Tarik K. (2026). Preoperative GLP-1 Receptor Agonist Use and Weight Loss Outcomes Following Bariatric Surgery.. Annals of surgery. https://doi.org/10.1097/SLA.0000000000007042