How Long Do Sulphur Burps Last on Mounjaro?

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 small intestine. When food sits in the stomach for longer than usual, it can ferment slightly, producing hydrogen sulphide gas. That gas, when released, is what causes the characteristic sulphur smell.

Typical timing and pattern

Most people who experience sulphur burps notice them peaking in the 24–48 hours after their weekly injection, when the medicine's activity is at its highest. Many find they settle back down within two to three days. Over time — particularly as the body adapts to a given dose — the intensity and frequency of sulphur burps often reduces. Some people find they return temporarily each time their prescriber adjusts their dose upward, then ease again as adjustment happens.

What tends to make them worse

• Eating very large meals, which adds to stomach fullness and slows digestion further
• High-fat or fried foods, which already take longer to digest
• Carbonated drinks, which add extra gas to the mix
• Eating too close to bedtime, when digestive activity naturally slows

Adjusting meal size and timing is something many people on Mounjaro find helpful to observe — not as a medical prescription, but as a practical pattern to notice and track. For a broader look at Mounjaro side effects and how to manage them, the full guide covers the range of commonly reported experiences. You may also find it useful to read about how long diarrhoea on Mounjaro typically lasts, as the two are sometimes linked to the same gastric-emptying effect.

According to NHS guidance, gastrointestinal side effects are among the most commonly reported with GLP-1 receptor agonist medicines, and they frequently improve with time.

One of the most useful things you can do when a side effect like sulphur burps appears is keep a simple log — when it started, how severe it felt, and how it changed over the days that followed. That pattern is often invisible in memory but becomes clear in data.

GLP Trackr's side-effect tracker lets you log symptoms like sulphur burps directly against your injection days, so you can see at a glance whether they consistently follow a dose and how long they last each week. Over time, that record can reveal whether they are improving — which is genuinely motivating — or whether a particular pattern keeps repeating in a way worth raising with your prescriber.

The app also includes a daily check-in where you can record how you're feeling each morning, giving you a fuller picture of how your body is responding week by week. If you want to explore whether what you eat around injection day seems to influence how you feel, the food logging feature — including an AI photo scan — makes it easy to track meals alongside symptoms without adding friction to your day.

You can also explore how long Mounjaro side effects generally last and, for those specifically curious about spelling variations and whether the experience differs, how long sulfur burps last with Mounjaro covers the same topic in depth.

If sulphur burps are severe, persistent beyond a few days, accompanied by significant nausea or vomiting, or feel unusual in any way, speak to your prescriber or doctor — they can review your full history and advise. GLP Trackr helps you record and present this information clearly; it is not a substitute for their guidance.

Ready to start spotting your own patterns? Download GLP Trackr on the App Store or Google Play and get started with a free 7-day trial — your injection log and side-effect tracker are ready to go from day one.