Sulfur burps on Ozempic or Mounjaro: why they happen and what helps

How common is burping on a GLP-1?

Burping shows up in the FDA-approved labels under its medical name, eructation. Here's what the labels report:

• Wegovy (semaglutide). In the weight-reduction trials, 7% of people on Wegovy injection reported burping, compared with less than 1% on placebo. The patient information lists belching and gas among the most common side effects.
• Ozempic (semaglutide). In the diabetes trials, burping was reported by up to about 3% of people, compared with 0% on placebo.
• Zepbound (tirzepatide). In the weight-reduction trials, 4% to 5% of people on Zepbound reported burping, compared with 1% on placebo.
• Mounjaro (tirzepatide). In the diabetes trials, 2.5% to 3.3% reported burping, compared with 0.4% on placebo.

MedlinePlus lists heartburn and burping among the side effects of semaglutide, and says to tell your doctor if a side effect is severe or doesn't go away.

So burping is real and more common than on placebo, though far less common than nausea or diarrhea. In the Wegovy trials, for example, 44% of people reported nausea and 30% reported diarrhea.

Why the burps can smell like rotten eggs

The labels count burps, not how they smell. That means there isn't solid data on how often "sulfur burps" happen on these medicines, or exactly why. But a few established facts point in the same direction.

These medicines slow stomach emptying. A 2025 review in the journal Endocrinology says GLP-1 medicines and tirzepatide slow gastric emptying, which is part of how they lower blood sugar after meals and may contribute to weight loss. The review says the effect varies from person to person and, with long-acting versions, may lessen with ongoing use. The Zepbound and Mounjaro labels also refer to delayed gastric emptying.

Gas can carry sulfur. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) explains that gas in the digestive tract comes from swallowed air and from bacteria breaking down carbohydrates your body didn't fully digest. It notes that an unpleasant odor in gas may be due to sulfur.

Put together, food that sits longer in the stomach, plus foods that tend to produce more gas, may make smelly burps more likely for some people. That's a reasonable explanation, not a proven one.

Other things add to it. MedlinePlus says belching is the body's way of releasing swallowed air, and that it can be linked to acid reflux (GERD) and to swallowing air without realizing it. The labels list gastroesophageal reflux disease and indigestion among GLP-1 side effects too.

Side effects are easier to manage when you can see what's setting them off. Olive is a health companion that checks in with you every day, looks at what you eat, and helps you build small habits that actually hold. It doesn't diagnose or treat anything, so questions about your medicine still belong with your prescriber.

What helps: eating habits

NIDDK's advice for gas and burping focuses on swallowing less air and changing how you eat. Its suggestions include:

• Eat smaller, more frequent meals instead of large ones. This also fits how a GLP-1 changes appetite.
• Eat slowly, and sit down to eat when you can rather than eating on the run.
• Don't talk while eating or drinking.
• Skip or limit fizzy drinks, and don't drink through a straw.
• Avoid chewing gum and sucking on hard candy, which make you swallow more air.
• If you smoke, talk with your doctor about quitting. If you wear dentures, make sure they fit well.

MedlinePlus adds: avoid eating quickly, avoid chewing gum, and cut back on gas-producing foods and drinks.

Our hub guide to what to eat with GLP-1 nausea covers small-meal ideas that are gentle on a slow stomach.

What helps: foods to watch

NIDDK lists foods and drinks that can lead to more gas in some people:

• Cruciferous vegetables such as broccoli, cauliflower, collard greens and kale
• Beans, peas and lentils
• Some fruits, such as apples, peaches and pears, and fruit juice
• Milk, ice cream and yogurt, if you're sensitive to lactose
• Drinks with high-fructose corn syrup, such as sodas, sports drinks and energy drinks
• Sugar-free candy and gum with sweeteners ending in "-ol," such as sorbitol, xylitol and erythritol
• High-fat foods, which can increase bloating
• More fiber than you're used to

You don't need to cut all of these. Many are healthy, and protein and fiber still matter on a GLP-1 (see our guide to protein on a GLP-1). NIDDK suggests keeping a short diary of what you eat and drink and when symptoms happen, so you and your doctor or dietitian can spot your own triggers. Then cut back on the worst offenders, especially at bigger meals.

A simple plan for a burpy day

1. Go small. Have a few small meals instead of one or two big ones.
2. Slow down. Put your fork down between bites, and sit down to eat.
3. Drink still, not sparkling. Skip fizzy drinks and straws, which add swallowed air.
4. Keep it plain. Choose lower-fat foods and skip the foods that set you off.
5. Ease the pressure. MedlinePlus says lying on your side or in a knee-to-chest position can help until the gas passes.
6. Write it down. Note what you ate and when the burps came.

If diarrhea is part of the picture too, our guide to diarrhea on a GLP-1 covers fluids and what to eat.

When burping needs a call

Most burping is a minor problem. MedlinePlus says to contact a health care provider if belching doesn't go away or comes with other symptoms such as belly pain or fever. NIDDK says to talk with your doctor if gas symptoms bother you or come with belly pain, constipation, diarrhea or weight loss.

On a GLP-1, MedlinePlus says to call your doctor right away or get emergency care for:

• Ongoing pain that starts in the upper left or middle of the belly and may spread to the back, with or without vomiting
• Pain in the upper belly with yellowing of the skin or eyes, fever, or clay-colored stools
• Severe stomach or intestinal problems
• Decreased urination or swelling of the legs, ankles or feet

The Wegovy patient information also says these medicines may raise the chance of food getting into the lungs during surgery or procedures that use anesthesia or deep sedation, so tell all your providers you take one before any procedure. And don't stop or change your medicine on your own. Your prescriber can tell you whether your symptoms fit the usual pattern.

This guide is general information, not medical advice. Talk with your prescriber about side effects, and don't start, stop or change any medicine or supplement without them.

Steadier meals, fewer surprises

Small changes to how and what you eat often make the biggest difference. Olive checks in with you every day and notices what's keeping your body stuck.

If steady habits haven't moved stubborn weight, Olive's Protocol is one option to look into. Prescriptions are only written after a medical consultation with a licensed provider. Not everyone qualifies.

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