GLP-1s Before Hip or Knee Replacement: When to Stop and Restart
More and more of my patients are on a GLP-1 medication like Ozempic, Wegovy, Mounjaro, or Zepbound when they come in for a hip or knee replacement. My current protocol is simple: stop it one week before surgery and restart one week after. Here’s why, why the rules keep changing, and what to do if you’re on one.
Key takeaways
- My current protocol: stop a weekly GLP-1 one week before hip or knee replacement and restart one week after.
- Anesthesia’s concern is slow stomach emptying. Food left in the stomach can be inhaled into the lungs under anesthesia, which is called aspiration.
- My own concern is the first week of recovery. I want you to have the appetite and energy to keep up, and to protect wound healing and muscle.
- The rules keep changing. My hold has gone from four weeks before and after, to two, to one, and hospitals may have their own protocols.
- Tell us what you take, the dose, and the day you take it. If you take it for diabetes, we’ll plan your blood sugar with the doctor who prescribes it.
More and more of my patients are on a GLP-1 medication when they come in for a hip or knee replacement: semaglutide (Ozempic, Wegovy) or tirzepatide (Mounjaro, Zepbound). It’s one of the most common questions I get before surgery: do I need to stop it, and for how long?
The short answer
My current protocol is to stop your GLP-1 one week before surgery and restart it one week after. That works well for my patients and my surgery center. If your surgery is at the hospital, it may have its own rules, which I explain below.
Why anesthesia cares
GLP-1 medications slow down how fast your stomach empties. That’s part of how they work: you feel full longer. But under anesthesia, food still sitting in the stomach can come back up and be inhaled into the lungs. That’s called aspiration, and while it’s rare, it’s serious.
Fasting overnight doesn’t always solve it. In one study, anesthesiologists used ultrasound to look at patients’ stomachs before elective procedures. Even after fasting, 35 of 62 patients on a GLP-1 still had food or fluid in the stomach, compared with 12 of 62 patients who weren’t on one. Other reports have found food in the stomach even after the medication was held for longer than usual.
Why I care
Anesthesia is focused on the stomach. As a surgeon, I’m more focused on the first week of recovery. After a hip or knee replacement, you’re up and walking the same day, and I need you to have the energy to keep up. On a GLP-1 in that first week, I worry about:
- Fatigue, from eating too little when your body needs fuel to recover.
- Wound healing, which depends on enough protein and calories.
- Muscle soreness and muscle loss, right when you need your legs the most. I’ve written more about protecting your muscle on a GLP-1.
To be fair to the medication: large studies of joint replacement patients on GLP-1s have been reassuring overall, and some have even found fewer infections. My hold isn’t because the medicine is dangerous. It’s a short, practical break so you go into recovery eating well and feeling strong.
Why the rules keep changing
The honest answer is that the goalposts keep moving. When these medications first became common, I had patients stop four weeks before surgery and four weeks after. Then we went to two weeks. Now my protocol is one week before and one week after.
The national guidance has moved too:
- 2023: the American Society of Anesthesiologists suggested holding a weekly GLP-1 for one week before elective surgery.
- 2024: a group of anesthesia, gastroenterology, and surgery societies said many patients can keep taking it, with a liquid diet the day before surgery for those at higher risk.
- 2025: a perioperative medicine consensus statement recommended continuing it in most patients, with clear liquids only for the 24 hours before surgery.
Those don’t fully agree with each other, and I expect more changes as we learn more about the risks for anesthesia, for surgery, and for recovery. That’s why the most important thing is to follow the instructions your own surgical team gives you.
Surgery center vs. hospital
I do most of my hip and knee replacements at Capital Orthopaedic Surgery Center in Germantown, and that’s where my one-week-before, one-week-after protocol applies.
Patients who have surgery at the hospital, Johns Hopkins Sibley Memorial in Northwest D.C., follow the hospital’s protocol. As of October 2026, if you’ve taken a GLP-1 in the last four weeks, Sibley asks you to fast for 24 hours before surgery. Your pre-op instructions will spell out exactly what you can and can’t have.
What to do if you’re on one
- Tell us the name, the dose, and the day of the week you take it, as soon as surgery is on the calendar
- Mark your last dose on the calendar: one week before surgery for a weekly shot
- If you take a daily GLP-1, tell us, and we’ll give you specific timing
- If you take it for diabetes, don’t just stop it; we’ll plan your blood sugar with the doctor who prescribes it
- If you take a dose inside the window by mistake, call my office right away
- Restart about one week after surgery, once you’re eating normally
- In that first week, focus on protein, fluids, and walking
GLP-1s can help you get to surgery
None of this means GLP-1s are bad for joint replacement patients. They’ve been genuinely useful for patients who need to bring down their BMI or their A1c before surgery. The goal is to arrive at surgery healthier and still strong, then take a short break around the operation.
Next step
If you’re on a GLP-1 and your hip or knee is limiting your life, that’s not a reason to wait. Come in, and we’ll plan your surgery and your medication timing together.
See me in D.C. or Germantown
I see patients at my offices in Washington, D.C. and Germantown, Maryland. Bring a list of your medications, including the day you take your GLP-1. Request an appointment.
Frequently asked questions
Do I need to stop Ozempic before hip or knee replacement?
In my practice, yes. My current protocol is to stop a weekly GLP-1 medication like Ozempic or Wegovy one week before hip or knee replacement and restart it one week after. Other surgeons and hospitals may use different timing, so follow the instructions your own team gives you.
How long before surgery should I stop Zepbound or Mounjaro?
For my surgery center patients, one week before surgery, the same as Ozempic and Wegovy. If your surgery is at the hospital, its protocol may differ. As of October 2026, Sibley asks patients who have taken a GLP-1 in the last four weeks to fast for 24 hours before surgery.
When can I restart my GLP-1 after joint replacement?
I have patients restart about one week after surgery, once they’re eating normally. That first week is when you need your appetite, energy, and protein the most.
Why do you have to stop GLP-1 medications before anesthesia?
GLP-1 medications slow down how fast your stomach empties. Under anesthesia, food still sitting in the stomach can come back up and be inhaled into the lungs, called aspiration. It’s rare, but it’s serious, so anesthesia teams take it very seriously.
What if I took my GLP-1 shot within a week of surgery?
Call my office right away and tell the anesthesia team. Depending on the timing, we may need to change your fasting instructions or move your surgery date. It’s much better to know ahead of time than on the morning of surgery.
Should I stop my GLP-1 if I take it for diabetes?
The same timing applies, but don’t stop without a plan. Let us know, and we’ll coordinate with the doctor who prescribes it so your blood sugar stays under control around surgery.
Can a GLP-1 help me get ready for joint replacement?
Yes. GLP-1 medications have been genuinely useful for patients who need to lower their BMI or A1c before surgery. The goal is to arrive at surgery healthier and still strong, then hold the medication for a short window around the operation.
References
- American Society of Anesthesiologists — Patients taking popular medications for diabetes and weight loss should stop before elective surgery (June 2023)
- Kindel TL, et al. Multisociety clinical practice guidance for the safe use of glucagon-like peptide-1 receptor agonists in the perioperative period. Clinical Gastroenterology and Hepatology, 2024.
- Perioperative management of patients taking glucagon-like peptide 1 receptor agonists: SPAQI multidisciplinary consensus statement. British Journal of Anaesthesia, 2025.
- Sen S, et al. Glucagon-like peptide-1 receptor agonist use and residual gastric content before anesthesia. JAMA Surgery, 2024.
- Reducing periprosthetic joint infection in patients with obesity: a systematic review and meta-analysis of the emerging role of GLP-1 receptor agonists. Cureus, 2025.
This article is for general education and is not a substitute for personalized medical advice. Recovery timelines vary by patient, procedure, medical history, and surgeon-specific protocol. Please consult Matthew Harb, M.D. about your specific condition.
What patients say
“A really smooth operation — I was discharged the same day and basically able to walk easily within a day.”
“I walked into the surgical center in great pain and walked out with a new knee and a renewed person.”
“My full knee replacement is a big success — six months after surgery I’m hiking and kayaking again.”
Keep learning
BMI and Joint Replacement
If you have been told to lose weight before you can have a hip or knee replaced, you are in a frustrating position — the arthritis is what stops you exercising. Here is what BMI actually does to your risk, where my own thresholds sit and why, when operating at a higher BMI is still the right decision, and what the 2025 guidelines now say about delaying surgery purely to hit a number.
Read articleArthritis & Joint PainDiabetes, A1c and Joint Replacement
A1c is a measure of how well your blood sugar has been controlled over roughly the past three months, and it changes your risk of infection after a joint replacement. Ideally it is under 7. My soft cutoff is 7.5, the range from 7.5 to 8 is a genuine discussion, and above 8 the risk is too high. Unlike weight, the guidelines still back delaying surgery for poorly controlled diabetes.
Read articleArthritis & Joint PainLosing Weight on a GLP-1? Protect Your Muscle
Weight loss is good for an arthritic hip or knee. Losing muscle along with it is not — and muscle is what protects the joint and carries you through a recovery. This is the part of the GLP-1 conversation that matters most orthopedically, and it is very fixable.
Read articleHave questions about your hip or knee?
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