On Ozempic? What to know before surgery.

If you take Ozempic, Wegovy, Mounjaro, Zepbound, or another GLP-1 medicine, you are in good company. A growing share of the patients I see before cosmetic surgery take one. These medicines work partly by slowing how quickly your stomach empties. That helps with appetite. It also matters on the day of surgery.

Why an empty stomach matters.

When you are asleep or deeply sedated, the reflexes that protect your airway relax. If food is still in your stomach, it can come back up and be breathed into the lungs. This is called aspiration, and it can cause a serious pneumonia. Fasting before surgery exists to prevent it.

Standard fasting times assume the stomach empties at a normal pace. On a GLP-1 medicine, it may not. Anesthesiologists have found food in the stomach of patients who fasted exactly as instructed. That is why these medicines get special attention.

How the guidance has changed.

In 2023, the American Society of Anesthesiologists advised holding weekly injections for a full week before surgery. Many patients went without their medicine, and some procedures were postponed.

In October 2024, the ASA and four other medical societies revised that advice. Most patients can keep taking their GLP-1 medicine and follow a liquid diet for the 24 hours before surgery. In 2025, a multidisciplinary consensus published in the British Journal of Anaesthesia, built on a systematic review of the evidence, reached a similar conclusion: no solid food for 24 hours, and firm limits on liquids in the last few hours.

That is the approach we follow at NCSS.

What this usually means for you.

• Keep taking your GLP-1 medicine unless we tell you otherwise. Stopping on your own can raise your blood sugar and set back your progress.
• The day before surgery, have clear liquids only: water, clear broth, apple juice, tea or black coffee, sports drinks, and plain gelatin. No solid food, no milk or cream, and nothing you have to chew.
• Stop all liquids at the time we give you, usually four hours before surgery. Your instructions will also say when to stop sugary drinks.
• Bring the name of your medicine, your dose, and the day of your last injection to your consultation.

Your exact times come from your Rest-Assure consultation. Follow those over anything general you read, including this article.

When we take extra care.

Some situations make a full stomach more likely:

• You started the medicine recently, or your dose went up in the past few weeks.
• You are on a high dose.
• You have nausea, vomiting, bloating, heartburn, or constipation, or you feel full after a few bites.

Tell us about any of these. Depending on the details, we may ask you to skip a dose, start the liquid diet earlier, or move your surgery date. I will ask again on the morning of surgery. If symptoms show up that day, I would rather reschedule than take a chance with your airway.

After surgery.

You can usually restart your GLP-1 medicine once you are eating normally again. Some nausea is common in the first days after surgery, and these medicines can add to it. If you are struggling to eat or drink, call your surgeon before your next dose.

Part of the Rest-Assure standard.

Every scheduled surgical patient at NCSS has a free pre-operative consultation with me. GLP-1 medicines are one of the things we go through line by line, along with everything else you take. The goal is simple: you keep the benefits of your medicine, and you arrive with a stomach that is safe for anesthesia.

— H. Rand Scott, MD

This article is general information and is not medical advice for your situation. Follow the instructions you receive from your surgeon and the NCSS team. Ozempic, Wegovy, Mounjaro, and Zepbound are trademarks of their manufacturers; NCSS has no affiliation with them.

H. Rand Scott, MD is founder and Medical Director of Newport Center for Special Surgery. Board-certified anesthesiologist, subspecialty training in interventional pain management at Penn State Milton S. Hershey Medical Center. He personally offers a free Rest-Assure pre-operative consultation to every scheduled surgical patient at NCSS.

The right starting point is a conversation.

Every scheduled surgical patient is offered a free Rest-Assure pre-operative consultation with Dr. Rand Scott personally — medical history, medication planning, and discharge coordination before the day of surgery.

Monday–Thursday, 8am–3pm · Friday by appointment only.