Peptides before surgery: do you have to stop GLP-1 drugs like Ozempic?

Do you have to stop GLP-1 before surgery?

• For most people, no. A 2024 guidance from 5 US groups, led by the American Society of Anesthesiologists, says most patients can keep taking GLP-1 drugs before surgery.
• A 2025 UK consensus from 8 groups says the same: keep taking them, and get a full risk check.
• The UK drug safety agency (MHRA) tells patients: take your medicines as usual and do not stop without talking to your doctor.
• Stopping has its own risks. The US guidance says it can raise blood sugar in people with diabetes.
• Your own team can still decide something different for you. Follow their plan.

Why do GLP-1 drugs matter for anesthesia?

• GLP-1 drugs slow how fast your stomach empties. That is part of how they make you feel full.
• The FDA labels for Wegovy and Zepbound say there are rare reports of "pulmonary aspiration" in people on these drugs. That means stomach contents got into the lungs during anesthesia or deep sedation.
• In those reports, food was still in the stomach even though people had fasted as told.
• The FDA labels also say the data are not enough to know if changing fasting rules or pausing the drug lowers the risk.
• That is why the labels say: tell your providers before any planned surgery.

Who is at higher risk before surgery?

• The US guidance lists higher risk when you are in the dose-raising phase (often the first 4 to 8 weeks or after a dose increase).
• Also: if you have nausea, vomiting, belly pain or bloating, if you are on a higher dose, or if you have a condition that slows the stomach, like gastroparesis or Parkinson's disease.
• The MHRA adds diabetic gastroparesis, obesity and reflux (GERD).
• The US guidance says weekly shots cause more stomach side effects than daily ones.

• GLP-1 side effects guide

What does the US anesthesia guidance say?

• It came out on Oct 29, 2024, from the ASA and 4 other US groups for stomach, weight-loss and surgery doctors.
• Most people can continue the drug.
• Higher-risk people may be asked to follow a liquids-only diet for 24 hours before the procedure.
• On the day of surgery, the team checks for symptoms. They may do a quick stomach ultrasound, change the anesthesia plan, or in rare cases delay the surgery.
• The ASA says about 1 in 8 US adults use GLP-1 drugs.

What do UK doctors say about GLP-1 and surgery?

• A January 2025 UK consensus (8 groups, published in the journal Anaesthesia) says people should keep taking GLP-1 and GIP/GLP-1 drugs before surgery.
• Everyone should get a full risk check, and the team should use ways to lower the chance of aspiration.
• The UK drug agency (MHRA) warned on Jan 28, 2025 that food can stay in the stomach despite fasting. It said a European review could not recommend a set time to pause the drugs.
• The MHRA told doctors to ask directly. Some people buy these drugs for weight loss online and do not mention them unless asked.

How long do GLP-1 drugs stay in your system?

• Each FDA label lists a "half-life." That is how long it takes for half the drug to leave your blood. See the chart below.
• Semaglutide (Wegovy, Ozempic) has a half-life of about 1 week. Tirzepatide (Zepbound, Mounjaro) is about 5 to 6 days. Liraglutide (Saxenda) is about 13 hours.
• The Wegovy label says semaglutide stays in the blood for about 5 to 7 weeks after the last shot.
• A half-life is not a stop schedule. The official groups above do not give one stop time for everyone. Ask your own team.

Should I stop BPC-157 or other peptides before surgery?

• Nobody knows. BPC-157, TB-500, KLOW, GLOW and other "research" peptides have never been studied with surgery or anesthesia.
• They are not FDA approved, so there is no label with surgery advice. The FDA says it has little or no safety data on BPC-157 for the ways people use it.
• Retatrutide is not approved either. It acts on GLP-1, like Wegovy and Zepbound, so tell your anesthesiologist if you use it.
• Collagen powder is a food supplement. Tell your team about it like any other supplement.
• Tell your surgeon and anesthesia team about every medicine, peptide and supplement you use, even ones bought online.

What should I tell my anesthesiologist?

• The name of every GLP-1 drug or peptide you use, including ones bought online, compounded or "for research."
• When you took your last dose, and whether you started or raised the dose in the last few weeks.
• Any nausea, vomiting, bloating, belly pain, heartburn or constipation lately.
• If you have diabetes, and what other diabetes medicines you take.
• If you have gastroparesis, reflux or Parkinson's disease.
• Ask: "Do I need to change anything about eating, drinking or my medicines before surgery?"

The numbers in charts

More charts: Peptides by the numbers

What the surgery guidance is based on

These are expert guidance documents and safety reports, not trials. No big trial has tested pausing GLP-1 drugs before surgery.

What each official source says about GLP-1 drugs and surgery