Sulfur Farts on Mounjaro: What's Going On and What to Log

Mounjaro works as a dual GIP and GLP-1 receptor agonist, and one of its well-documented effects is slowing gastric emptying — the rate at which food moves from the stomach into the intestines. When food lingers longer in the digestive tract, gut bacteria have more time to ferment it, and that fermentation process can produce hydrogen sulfide and other sulfur-containing gases. The result, for many people, is flatulence with a distinctly eggy or sulfurous smell.

This mechanism is the same one that underpins other gastrointestinal side effects associated with GLP-1 medicines. You may notice it is worse after certain foods — particularly those naturally high in sulfur compounds, such as eggs, cruciferous vegetables (broccoli, cauliflower, cabbage), garlic, and onions. Eating more slowly and in smaller portions, as many people on Mounjaro naturally do, can sometimes help, though food choices play a big role too.

For context on the wider picture of gut-related side effects, the full guide to Mounjaro side effects covers the range of gastrointestinal changes commonly reported. If sulfur-smelling burps are also an issue — which often goes hand-in-hand — the pages on sulfur burps on Mounjaro and what causes sulfur burps with Mounjaro explain that side of things in more detail.

• Common trigger foods: eggs, broccoli, cauliflower, cabbage, garlic, onions, leeks
• Timing: often most noticeable in the first few days after a dose or dose increase
• Pattern: tends to ease over time for many people, though individual experience varies

If the gas is accompanied by severe abdominal pain, persistent vomiting, or any symptom that feels worrying or unusual, contact your healthcare professional promptly — do not try to manage it on your own.

One of the most useful things you can do with any recurring side effect is track it — and GLP Trackr's side-effect logging feature is built exactly for this. Rather than trying to remember when the symptom was worst or what you had eaten that day, you can log it in the moment: the date, how noticeable it was, and any notes about food or timing. Over days and weeks, patterns often become visible that are easy to miss otherwise.

That logged data is genuinely useful to bring to your next appointment. The app's doctor report feature pulls together your side-effect entries, food logs, and dose history into a clear summary — so you can have a more informed conversation with your prescriber about what you have been experiencing, rather than relying on memory alone.

If you have noticed that particular foods seem to make the sulfur smell worse, the food logging tool (including AI photo scan and barcode search) lets you capture meals quickly alongside your symptom entries, making it easier to spot those connections. The page on tracking sulfur burps on Mounjaro has further practical context on logging these kinds of gut symptoms.

GLP Trackr is a tracking and journaling tool — it is not a substitute for advice from your prescriber or doctor, and any decision about your treatment should be made with them. If symptoms are persistent, severe, or worrying, always reach out to your healthcare professional rather than relying on self-management alone.

Start logging your side effects and spotting your own patterns — GLP Trackr is free to try for 7 days on the App Store and Google Play.