Why do I get sulphur burps on Mounjaro?

Sulphur burps, sometimes called eggy burps, happen because Mounjaro slows down how quickly food leaves your stomach. That extra time gives gut bacteria longer to ferment food before it moves on, and one by-product of that fermentation is hydrogen sulphide gas, the same gas responsible for the rotten egg smell. It's unpleasant and often embarrassing, but it's a mechanical side effect of slower digestion, not a sign that something has gone wrong.

This article is general information, not personal medical advice. If burping is severe, persistent, or comes with pain, vomiting, or other symptoms described further down, contact your GP or prescriber.

Does this mean Mounjaro isn't working, or something's wrong?

No. Sulphur burps aren't a sign of poor digestion or that nutrients aren't being absorbed properly. If anything, they're a side effect of the mechanism doing exactly what it's meant to: slowing gastric emptying is part of how Mounjaro helps with appetite and blood sugar. It's not pleasant, and it's not a marker of how much weight you'll lose either, some people get it a lot and lose weight slowly, others barely notice it and lose weight quickly. It's simply a common side effect, not a signal either way.

What foods make sulphur burps worse?

The foods most commonly linked to sulphur burps are the ones naturally higher in sulphur compounds or harder to digest quickly:

• Eggs, red meat, and dairy
• Garlic and onions
• Cruciferous vegetables such as broccoli, cabbage, and cauliflower
• Fibre-rich foods like beans, nuts, and seeds, in large amounts
• Alcohol and carbonated or fizzy drinks
• Very fatty, greasy, or heavily processed meals

None of these need to be avoided permanently, and several (beans, vegetables, dairy) are genuinely useful sources of protein, fibre and calcium while you're on Mounjaro. The practical approach most guides suggest is temporarily easing off the worst offenders while your body adjusts to a new dose, rather than cutting them out for good.

How long do sulphur burps last?

They tend to be most noticeable in the first couple of weeks after starting Mounjaro, and again for a few days after each dose increase, while your digestion adjusts to the new level. For most people, they ease off over the following weeks as the body gets used to it. If they're still just as bad months into a stable dose, it's worth mentioning to your prescriber, since a slower dose increase or a longer pause at your current dose sometimes helps.

How to reduce sulphur burps

• Eat smaller, more frequent meals rather than large ones, so there's less sitting in your stomach at once.
• Eat slowly and chew thoroughly, which reduces the air swallowed alongside food.
• Stay upright for two to three hours after eating rather than lying down, which helps things move through more easily.
• Keep well hydrated, since dehydration tends to make digestive symptoms worse generally.
• Go easier on high-fat meals, especially around the day of your injection or dose increase.
• Track what you eat for a week or two if you're not sure what's triggering it. Sulphur burps are individual: what bothers one person may not bother another.
• Ask a pharmacist about over-the-counter options such as simethicone-based anti-gas tablets, which some people find helpful for the associated bloating.

Does alcohol make it worse?

Yes. Alcohol is one of the more commonly reported triggers, on top of everything else it can do alongside Mounjaro. If you're going to drink, doing so alongside food and in smaller amounts tends to be easier on digestion generally, sulphur burps included. See our guide to drinking alcohol on Mounjaro for more detail.

When to see a doctor

Sulphur burps on their own are unpleasant but not dangerous. Get medical attention if they come with any of the following, since these can point to something else, including rare but serious causes such as pancreatitis or gallbladder problems:

• Severe or persistent abdominal pain, particularly if it spreads to your back
• Repeated vomiting, especially if you can't keep fluids down
• Fever, yellowing of the skin or eyes, or unusually dark urine
• Black or bloody stools

Frequently asked questions

How do you get rid of sulphur burps on Mounjaro?
Smaller meals, eating slowly, staying hydrated, temporarily easing off high-sulphur or fatty trigger foods, and staying upright after eating all help. They usually improve on their own as your body adjusts to your current dose.

How long do sulphur burps last on Mounjaro?
They're typically worst in the first couple of weeks on a new dose and ease off over the following weeks. They often flare up again briefly after each dose increase.

What foods trigger sulphur burps on Mounjaro?
Eggs, red meat, dairy, garlic, onions, cruciferous vegetables, high-fibre foods in large amounts, alcohol, fizzy drinks, and fatty or greasy meals are the most commonly reported triggers.

Do sulphur burps mean Mounjaro is working?
They're a side effect of the slowed digestion that's part of how Mounjaro works, but they aren't a reliable marker of how much weight you'll lose. Some people get them a lot and lose weight slowly, and vice versa.

Should I stop Mounjaro if I get sulphur burps?
Not on their own, they're a common and manageable side effect. Speak to your prescriber if they're severe, persistent, or paired with the warning signs above, since they may adjust your dose or pace of increase.

A note on covering nutrient gaps

Sulphur burps themselves don't call for a supplement, cutting back on the trigger foods above and giving your digestion time to adjust does more than anything in a bottle. But if you're avoiding several of those triggers at once, eggs, red meat, dairy, cruciferous veg, it's worth checking your overall diet isn't narrowing too much as a result. Wellgard's My Journey is a high-strength multivitamin that can help cover the gaps if your usual food range has shrunk while you work out what suits you. As with any high-strength all-in-one, check the label's vitamin A content if you're pregnant or trying to conceive, and flag its biotin content before a blood test.

For more on managing digestion, diet and side effects on Mounjaro, see our guides to which vitamins to take on Mounjaro and does Mounjaro cause hair loss.

This guide is for general information and isn't a substitute for personal medical advice. Always speak to your GP or pharmacist about persistent or severe side effects, or before starting a new supplement.