Key Points
- Common but not universal: Affects some GLP-1 users, especially early on
- Caused by delayed gastric emptying: Food sits longer → more fermentation → sulfur gas
- Certain foods make it worse: Eggs, cruciferous vegetables, high-fat foods, dairy
- Usually improves with time: Your body adapts over weeks to months
- Dietary changes help most: Smaller meals, avoid trigger foods, eat slowly
What Causes Sulfur Burps on GLP-1s?
The infamous "rotten egg" smell comes from hydrogen sulfide gas. Here's the chain of events:
- GLP-1s slow gastric emptying: Food stays in your stomach longer than normal
- Sulfur-containing foods sit and ferment: Bacteria break down proteins containing sulfur amino acids
- Hydrogen sulfide gas is produced: The classic "rotten egg" compound
- Gas escapes as burps: And they smell terrible
This is essentially the same process that creates sulfur burps with small intestinal bacterial overgrowth (SIBO)—food fermentation in the upper GI tract where it shouldn't be fermenting.
Foods That Trigger Sulfur Burps
| Food Category | Examples | Why They're Problematic |
|---|---|---|
| Eggs | All preparations, especially hard-boiled | High in sulfur-containing amino acids (cysteine, methionine) |
| Cruciferous vegetables | Broccoli, cauliflower, cabbage, Brussels sprouts | Contain sulfur compounds that break down to H₂S |
| Alliums | Garlic, onions, leeks, shallots | High in sulfur compounds |
| Red meat | Beef, lamb, pork | High in sulfur amino acids; digests slowly |
| High-fat foods | Fried foods, fatty cuts, butter | Slow digestion further; compound delayed emptying |
| Dairy | Milk, cheese, cream | Contains sulfur; may worsen if lactose intolerant |
| Beer/wine | Especially preservative-heavy | Sulfites; fermentation compounds |
| Dried fruits | Especially sulfur-preserved | Sulfur dioxide used as preservative |
Proven Strategies to Reduce Sulfur Burps
1. Modify Your Diet
Most Effective Strategy
Avoid high-sulfur foods for 1-2 weeks to see if symptoms resolve. Common triggers: eggs, broccoli, cabbage, onions, garlic. If burps stop, reintroduce foods one at a time to identify your specific triggers.
2. Eat Smaller Meals
- Large meals overwhelm an already-slow stomach
- Aim for 4-5 small meals instead of 2-3 large ones
- Stop eating before you feel full (you'll feel full later)
3. Eat Slowly and Chew Thoroughly
- Rushed eating = swallowed air = more burping
- Inadequately chewed food ferments more
- Put fork down between bites
- Aim for 20+ minutes per meal
4. Stay Upright After Eating
- Don't lie down for 2-3 hours after eating
- Gravity helps food move through
- Light walking after meals can help
5. Reduce Fat Intake
- Fat delays gastric emptying further
- Choose lean proteins (chicken breast, fish, turkey)
- Bake/grill instead of fry
- Limit butter, oils, creamy sauces
Supplements and OTC Remedies
| Remedy | How It Helps | Notes |
|---|---|---|
| Pepto-Bismol (bismuth subsalicylate) | Binds hydrogen sulfide; reduces odor | Can cause black stool (harmless); avoid with aspirin allergy |
| Activated charcoal | Absorbs gas and toxins | Take away from medications (can absorb them too) |
| Digestive enzymes | Help break down food faster | Take with meals; mixed evidence |
| Probiotics | May improve gut bacteria balance | Results vary; try for 4+ weeks |
| Ginger | Promotes gastric motility; reduces nausea | Tea, capsules, or fresh |
| Peppermint tea | Relaxes GI smooth muscle | May worsen reflux in some |
Pepto-Bismol Tip
Many users swear by Pepto-Bismol (bismuth subsalicylate) for sulfur burps. The bismuth binds to hydrogen sulfide, neutralizing the smell. Take 1-2 tablets before meals. Note: don't use long-term without consulting your doctor, and be aware it can turn stool and tongue black (harmless).
Medication Timing Strategies
- Inject before your lightest eating day: If weekends involve more eating, inject Monday
- Time-of-day experimentation: Some find morning vs. evening injection affects symptoms
- Slower titration: Ask your doctor about extending time at lower doses
When Sulfur Burps Are Worst
Expect sulfur burps to be most problematic:
- First 4-8 weeks: While your body adjusts to the medication
- After dose increases: Each titration step may restart symptoms
- Days 1-3 after injection: When medication levels are highest
- After large or fatty meals: When stomach emptying is most delayed
Good News: It Usually Gets Better
For most people, sulfur burps improve over time:
- Your stomach adapts to delayed emptying
- You learn which foods trigger you
- You naturally eat smaller portions
- Some "tachyphylaxis" of gastric effects (the body partially adapts)
When to See a Doctor
Contact your healthcare provider if:
- Sulfur burps are accompanied by severe abdominal pain
- You're vomiting frequently
- You notice blood in vomit or stool
- Symptoms are so severe you can't eat adequately
- You're losing weight too rapidly
- Symptoms persist despite all dietary modifications
Quick Reference: Do's and Don'ts
| Do | Don't |
|---|---|
| Eat small, frequent meals | Eat large portions |
| Choose lean proteins | Eat fried or fatty foods |
| Chew thoroughly | Rush through meals |
| Stay upright after eating | Lie down after meals |
| Keep a food diary | Eat lots of eggs/broccoli together |
| Try Pepto-Bismol if severe | Suffer in silence |
| Be patient—it often improves | Give up on the medication too soon |
The Bottom Line
Sulfur burps are a common and unpleasant side effect of GLP-1 medications, caused by delayed gastric emptying allowing sulfur-containing foods to ferment. The most effective strategies are dietary: avoid high-sulfur foods (eggs, cruciferous vegetables, onions, garlic, red meat), eat smaller meals, reduce fat intake, and eat slowly. Pepto-Bismol (bismuth subsalicylate) can help by binding hydrogen sulfide. For most people, symptoms improve over the first 1-3 months as the body adapts and you learn your trigger foods. If symptoms are severe, persistent, or accompanied by pain or vomiting, consult your healthcare provider. Don't let sulfur burps discourage you—this side effect is manageable and usually temporary.
Sources
- FDA. Wegovy Prescribing Information - Adverse Reactions. 2021, updated 2024.
- FDA. Zepbound Prescribing Information - Adverse Reactions. 2023.
- Nauck MA, Meier JJ. GLP-1 Receptor Agonists and GI Effects. Diabetes Care. 2019.
- Camilleri M. Clinical Practice: Diabetic Gastroparesis. N Engl J Med. 2007.
- Levitt MD, et al. Hydrogen Sulfide and the Gastrointestinal Tract. Dig Dis Sci. 1998.
- Suarez FL, et al. Bismuth Subsalicylate Markedly Decreases Hydrogen Sulfide. Gastroenterology. 1998.
- Novo Nordisk. Patient Guide - Managing Side Effects. 2024.
- Eli Lilly. Zepbound Patient Information. 2024.