Weight Loss Medications Before Surgery

Key Considerations for Patients on Weight Loss Medications (Mounjaro/Wegovy) Before Surgery

• Many patients are using GLP-1 medications such as Semaglutide (Wegovy) or Tirzepatide (Mounjaro) to support weight loss, either before planned surgery or while they require surgery for other, unrelated reasons. Whether you're using these medications to manage your weight before a procedure or you're taking them as part of your ongoing treatment, it’s important to understand how they can affect your surgery and how to prepare.
• This is a common enquiry here at Yorkshire Wellness Clinic, and it’s essential to be fully informed before your surgery. There’s often conflicting advice about whether or not you should stop your medication, primarily due to the relative inexperience of many in the healthcare field with these newer medications in a surgical context.
• As an anaesthetist who works in a weight management clinic, I understand the importance of clear guidance for both patients and healthcare providers. GLP-1 medications are increasingly prescribed to manage obesity and type 2 diabetes, which means more patients are likely to be taking these medications when they need surgery.
• It is great news to see that the Association of Anaesthetists along with experts from Diabetes, Obesity and UK clinical pharmacy societies have published a consensus statement early 2025 to outline their recommendations for managing your GLP medications such as Wegovy and Mounjaro during your surgery.

Why Do These Medications Affect Surgery?

• Wegovy and Mounjaro help control blood sugar levels and promote weight loss. However, one side effect of these drugs is delayed gastric emptying, which means your stomach takes longer to empty after eating. This can increase the risk of pulmonary aspiration—a condition where food or liquid from the stomach accidentally enters the lungs during anaesthesia. Pulmonary aspiration can lead to serious complications, like lung infections, breathing difficulties and potentially unplanned intensive care admissions.
• It’s important to note that anaesthetists are very experienced in managing patients with delayed gastric emptying. There are well-established techniques to minimise the risks of pulmonary aspiration, and your healthcare team will make sure you're properly prepared to manage this during your procedure.
• Hence why we always advocate patients keep their anaesthetist and healthcare professionals aware that they are taking weight loss medications privately. These medications don't always show up clearly on your GP records so it is common this information could be missed.

Why You Might Not Want to Stop Your Medication

• It’s completely understandable that you may not want to stop your GLP-1 medication—especially if you’re in the middle of your weight loss journey and seeing progress. For many patients, these medications are helping to achieve significant weight loss and improvements in overall health. Some patients are in the middle of a titration phase (gradually increasing the dose to achieve optimal results), and stopping medication could disrupt their progress or the adjustment period.
• Additionally, if you're already managing a medical weight loss plan, stopping your medication could feel like a setback or create uncertainty about whether your progress will stall. I want to validate these concerns—it's natural to want to keep the momentum going, especially when you've been committed to reaching your health goals.
• The good news is that you don’t necessarily have to stop your medication before surgery. Proper planning and ongoing communication with your healthcare team are key to making sure you stay on track while ensuring that surgery proceeds as safely as possible.
• We can help navigate this by making sure you continue on your journey while also considering the necessary adjustments for the procedure.

What You Need to Do Before Surgery

• When you have surgery planned, it’s essential to be fully transparent with your healthcare team.
• Inform your pre-assessment team and anaesthetist about any medications you're taking, including GLP-1 medications like Wegovy and Mounjaro. This is crucial for your safety.
• In the pre-assessment phase, your anaesthetist will discuss how these medications might affect your anaesthesia, and a clear plan can be made to reduce any potential risks.

What Should You Do If You're on GLP-1 medications like Wegovy or Mounjaro for weight loss prior to surgery?

• Continue taking your medication before surgery: In general, it's recommended to continue taking your GLP-1 medications before surgery, unless your healthcare provider advises otherwise.
• Risk Assessment and Mitigation: Before your procedure, your anaesthetist will assess the risk of pulmonary aspiration (stomach contents entering the lungs) and will discuss strategies to minimise this risk. Fasting guidelines will also be provided to ensure your stomach is as empty as possible during anaesthesia.
• Shared Decision-Making: If you’re unsure, don’t hesitate to ask questions and have an open conversation with your healthcare team. Shared decision-making ensures that you’re involved in the planning and fully understand how your medication affects the surgery and recovery process.

Summary:

• There is a lot of conflicting advice around the use of GLP-1 medications before surgery, which can be overwhelming.
• The general consensus, as highlighted in the recent consensus statement from the Association of Anaesthetists (9th January 2025), is that, with proper risk assessment and planning, these medications do not have to be stopped before surgery.
• The key is communication—ensuring your anaesthetist, surgeon, and weight management team are all on the same page and aware of the medications you're taking.
• Anaesthetists are very experienced in managing patients with reduced gastric emptying. There are well-established techniques to prevent the risk of pulmonary aspiration, so you can feel confident that your healthcare team is prepared to manage this during your procedure.

Dr Kristopher Welsh