GLP-1 medicines before surgery or an anaesthetic
Made with AI tools and overseen by an Australian GP · Updated 8 November 2026
These medicines slow your stomach down, which is part of how they work. Under an anaesthetic, a stomach that hasn’t emptied is a real safety issue.
Quick answer: Australian guidance from 2025 says keep taking your GLP-1 medicine before a procedure, but have only clear fluids for 24 hours beforehand, then follow the usual fasting. These medicines slow stomach emptying, so food can stay in the stomach and be breathed into the lungs under anaesthetic. Always tell your anaesthetist.
Why it matters
- GLP-1 medicines slow stomach emptying. Under anaesthesia or sedation, stomach contents can be breathed into the airways and lungs (aspiration).
- The US product information reports rare cases of aspiration in people who had followed the usual fasting advice.
Australian advice (2025)
From the Australian Diabetes Society, ANZCA, the Gastroenterological Society of Australia and obesity services.
- Keep taking it. Stopping before a procedure isn’t recommended.
- Clear fluids for 24 hours, from waking on the day before, then the usual fasting before the procedure. Your hospital will give exact times.
- Diabetes and insulin? Clear fluids are mostly sugary, so ask for a diabetes plan for that day.
- Feeling fine doesn’t prove an empty stomach. Having no gut symptoms isn’t a reliable sign.
- Missed the clear fluid day? Tell the team. They may check your stomach with ultrasound, take other precautions or reschedule.
Elsewhere
- UK: the MHRA says keep taking your medicine as usual and don’t stop without talking to your doctor.
- US: the product information tells people to let their healthcare providers know before any planned surgery or procedure.
Tell your anaesthetist, surgeon or proceduralist that you take a GLP-1 medicine, ideally when the procedure is booked. Get urgent help (000 in Australia, or your local emergency number) for trouble breathing, or a cough with fever, after an anaesthetic.
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Common questions
Should I stop Ozempic before surgery?
Not usually. 2025 Australian guidance says to keep taking GLP-1 medicines and to have a 24-hour clear fluid diet before the procedure instead. Follow your own team’s instructions.
Why do I need a clear fluid diet before my procedure?
GLP-1 medicines slow stomach emptying, so solid food can still be in your stomach after the usual fast. Clear fluids for 24 hours lowers the chance of food being breathed into the lungs under anaesthetic.
Does this apply to a gastroscopy or colonoscopy with sedation?
Yes. The Australian advice covers procedures under anaesthesia or sedation, and the Gastroenterological Society of Australia helped write it.
What if I didn’t do the 24-hour clear fluid diet?
Tell the team before your procedure. They may check your stomach with ultrasound, use other precautions or move the procedure to another day.
I have diabetes and use insulin. What about the clear fluid day?
Clear fluids are mostly sugary, so your insulin may need adjusting. Ask your doctor or diabetes team for a plan well before the day.
Evidence and more information
- Hocking et al, Anaesthesia and Intensive Care 2025: ADS, ANZCA, GESA and NACOS clinical practice recommendations on peri-procedural GLP-1 and GLP-1/GIP medicines
- ANZCA: GLP-1 receptor agonists, clinical practice recommendations and FAQs
- UK MHRA: GLP-1 medicines for weight loss and diabetes, what you need to know (updated February 2026)
- US FDA prescribing information for Wegovy (semaglutide), February 2026: side-effect table, warnings
maladywise.com/glp-1/surgery-anaesthesia/