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semaglutide (Wegovy) and sulfur (rotten-egg) burps: incidence, timing, mechanism, evidence-graded management, and when to escalate.
| Drug | Reported incidence | vs placebo |
|---|---|---|
| Wegovy (this page) | Less common | — |
| Ozempic | Less common | — |
| Mounjaro | Less common | — |
| Zepbound | Less common | — |
| Saxenda | Less common | — |
Cells graded on a calm severity scale (lighter = lower). Figures are from each drug's pivotal trial / FDA label and are not head-to-head; doses and populations differ.
Typical onset, peak, and resolution from pivotal-trial timing. Drag the slider to read what most patients experience that week. Individual experience varies — this is a guide, not medical advice.
Can appear within days of a dose, often after high-protein, high-sulfur, or fatty meals. Episodic; tends to track dose steps and specific meals rather than persisting constantly.
Delayed gastric emptying on Wegovy lets food (especially sulfur-rich protein) sit and ferment longer, releasing hydrogen-sulfide gas — hence the rotten-egg smell.
Eat smaller meals and cut high-sulfur foods during flares (eggs, red meat, garlic, onion, cruciferous veg).
Mechanistically sound dietary trigger reduction; limited formal trial evidence.
Do not lie down for ~2 hours after eating.
Reduces retention/reflux; low-risk, modest evidence.
Slowing titration reduces gastric retention and the burps with it.
Holding the current dose an extra 4 weeks (instead of stepping up on schedule) is the single best-evidenced way to blunt this — slower titration was protocol in every pivotal trial.
OTC simethicone or bismuth subsalicylate help some patients short-term.
Symptomatic relief; individual response.
Each step is graded A (strongest evidence) to D (weakest), on the same scale used across LoseLab. Grades reflect strength of supporting evidence, not how essential a step is for you.
Sulfur burps are unpleasant but usually benign and meal-linked. They track gastric retention, so the same slow-titration, small-meal moves that fix nausea fix these too.
| Symptom | Incidence | Onset |
|---|---|---|
| Nausea | 44% | Usually 24–48 h after the first dose and after each dose step-up. |
| Vomiting | 24% | Clusters in the first week of each new dose step, often after overeating past the new appetite ceiling. |
| Diarrhea | 30% | Most common in the first 4 weeks of each titration step; often alternates with constipation. |
| Constipation | 24% | Builds gradually over the first 4–8 weeks. |
| Fatigue | 11% | Most common in the first month of titration and during periods of very low intake. |
| Headache | 14% | Variable; clusters around titration and dehydration episodes (after nausea or diarrhea). |
| Sulfur burps | Less common | Can appear within days of a dose, often after high-protein, high-sulfur, or fatty meals. |
| Injection-site reaction | 4% | Within hours to a day or two of an injection. |
| Facial fat loss ("Ozempic face") | Common | Becomes visible after roughly 8–12% total body-weight loss, typically months 3–6. |
| Muscle / lean-mass loss | Common | Begins with weight loss itself (weeks–months); proportion of lean loss is highest when loss is fast and protein/training are low. |
| Hair loss (telogen effluvium) | 3% | Typically 2–4 months after the period of fastest weight loss (delayed, by design of the hair cycle). |
Editorial summary, not medical advice. Incidence figures from FDA prescribing information and pivotal trial publications; qualitative bands are used where no trial reports a clean percentage. Individual experience varies. Coordinate side effect management with your prescriber.