Managing GLP-1 Medications (Semaglutide, Tirzepatide) Before Surgery

Why This Question Comes Up So Often

GLP-1 receptor agonists (semaglutide) and GLP-1/GIP dual agonists (tirzepatide) reduce appetite and can also slow gastric emptying. This is part of the intended feeling of fullness during treatment, but it becomes a separate consideration when general anaesthesia is planned.

Protective reflexes are suppressed during general anaesthesia. If the stomach is fuller than expected, its contents can move up into the oesophagus and potentially into the airway (pulmonary aspiration). The entire perioperative discussion centres on how to reduce this one risk.

At the same time, stopping the medication unnecessarily or for too long has its own costs: worsened blood glucose control, interrupted treatment continuity, and having to restart the dose-escalation process from the beginning. This is why the current approach is not 'stop it in everyone' but 'assess the risk for this individual patient.'

The Core Framework of the 2024 Multi-Society Guidance

The joint consensus statement published in 2024 by anaesthesia and metabolic/bariatric surgery societies sets out a more balanced framework than the earlier blanket 'always stop before surgery' tendency. Under this framework, whether to continue or pause the medication is decided through an individualised risk assessment rather than a single calendar rule.

In short, the consensus is this: in selected low-risk patients with no gastrointestinal symptoms and a stable treatment course, continuing the medication may be considered; where risk indicators are present, the plan is adjusted and additional precautions may be discussed — for example, extending the pre-operative clear-liquid diet, adapting the airway-management approach, or in some cases assessing stomach contents with ultrasound.

This article summarises that document in patient-friendly language; the original guidance is written for clinicians and does not constitute an individual patient instruction. The original text can be found via the references section below.

Situations That Change the Plan

The items below are typical situations that lead the team to take a more cautious approach. They are examples of what matters, not a checklist to apply yourself:

What Information Is Taken Into Account?

Dose stage: Having recently started the medication or being in the dose-escalation period is when gastric emptying is affected the most.

Current symptoms: Nausea, vomiting, early satiety, bloating, belching, constipation, or a sense that food is 'sitting' in the stomach.

Dose level and duration of use: Long-term use at a stable, higher dose is not assessed in the same way as a recent start at a low dose.

Coexisting conditions: Type 2 diabetes, long-standing diabetes-related delayed gastric emptying (gastroparesis), reflux, and previous gastrointestinal surgery.

Type of procedure: General anaesthesia, sedation or an endoscopic procedure; emergency or planned.

Other medications: Blood-glucose-lowering drugs, medications that affect gastric emptying, and any other treatments already scheduled to be paused before surgery.

Who Makes the Decision?

The perioperative GLP-1 decision is not made by a single physician alone. The operating surgeon, the anaesthetist responsible for the procedure, and the prescribing physician (endocrinology, internal medicine or family medicine) assess it together.

The patient's role is to provide the information that makes this assessment possible: the medication name, dose, date of the last injection, any recent dose changes, and digestive symptoms over the past few weeks. Bringing this information as a written list to the appointment makes the plan much safer.

Patients should not stop, skip, change the dose of, or continue the medication on their own simply because surgery is scheduled. Whether to pause it — and, if so, when to restart — is part of the team's plan.

An Additional Note for Patients Considering Bariatric Surgery

Some patients are already using these medications as part of obesity treatment before metabolic-bariatric surgery is considered. In this situation the medication is part of the path towards surgery, not a sign of 'failure.'

Whether the medication and surgery are used sequentially or together, and whether treatment continues after surgery and when it is reassessed, are separate decisions. These are also determined through examination, testing and the patient's own preferences.

What to Bring to Your Pre-Operative Appointment

An up-to-date list of all medications and supplements you take, with doses and frequency.

The date of your last GLP-1 or GLP-1/GIP injection and when the dose was last changed.

How often you have experienced nausea, vomiting, early satiety or bloating over the past month.

Any diagnoses of diabetes, reflux or gastroparesis, and details of previous gastrointestinal surgery.

Your past experiences with anaesthesia and any known drug allergies.

References

• American Society of Anesthesiologists — Multi-society clinical practice guidance on GLP-1 receptor agonists and perioperative management (2024) (opens in a new tab)
• WHO — Global guideline on the use of GLP-1 medicines in treating obesity (2025) (opens in a new tab)
• NICE NG246 — Overweight and obesity management (opens in a new tab)
• ASMBS / IFSO — 2022 Indications for Metabolic and Bariatric Surgery (opens in a new tab)