Bad smelling burps are an unpleasant but relatively common side effect experienced by some people taking Ozempic (semaglutide) for type 2 diabetes. This GLP-1 receptor agonist works by slowing gastric emptying, which helps control blood glucose levels but can lead to digestive disturbances including malodorous eructation. Understanding why this occurs and how to manage it can help patients continue their treatment more comfortably. This article explores the mechanisms behind Ozempic-related burps, their prevalence, practical management strategies, when to seek medical advice, and alternative treatment options if symptoms persist.

Why Ozempic Can Cause Bad Smelling Burps

Ozempic (semaglutide) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for the treatment of type 2 diabetes mellitus. Its mechanism of action involves slowing gastric emptying, which prolongs the time food remains in the stomach. This delayed gastric emptying is therapeutically beneficial for glycaemic control and appetite regulation, but it can also lead to gastrointestinal side effects, including bad smelling burps (eructation).

When food stays in the stomach for longer periods, this can contribute to reflux and burping. The unpleasant odour may be associated with volatile sulphur compounds, which can be produced when sulphur-containing foods such as eggs, red meat, cruciferous vegetables (broccoli, cabbage, Brussels sprouts), garlic, and onions are digested. Additionally, delayed gastric emptying can contribute to gastro-oesophageal reflux, allowing stomach contents and gases to travel back up the oesophagus, further exacerbating symptoms.

Ozempic's effect on gastrointestinal motility is typically most pronounced during the initial titration phase or following dose increases. The slowing of gastric emptying is an intended pharmacological effect that contributes to the medication's efficacy in reducing postprandial glucose excursions and promoting satiety. However, this same mechanism underlies many of the gastrointestinal adverse effects reported by patients. This effect tends to attenuate over time with continued treatment. Understanding this physiological basis helps both patients and healthcare professionals anticipate and manage these symptoms more effectively.

How Common Are Digestive Side Effects with Ozempic?

Gastrointestinal side effects are among the most frequently reported adverse reactions associated with Ozempic therapy. According to the Summary of Product Characteristics (SmPC) approved by the MHRA, nausea is very common (may affect more than 1 in 10 people), whilst vomiting, diarrhoea, abdominal pain, and constipation are common (may affect up to 1 in 10 people). Whilst bad smelling burps are not specifically quantified as a distinct adverse effect in the Ozempic SmPC or clinical trial data, they may fall within the broader category of gastrointestinal disturbances experienced by patients.

The incidence and severity of digestive side effects typically follow a predictable pattern. Symptoms are most pronounced during the initial weeks of treatment and following dose escalations, as the body adjusts to the medication's effects on gastric motility. The standard titration schedule for Ozempic begins at 0.25 mg once weekly for four weeks, increasing to 0.5 mg weekly, with potential further increases to 1 mg or 2 mg depending on glycaemic control and tolerability. This gradual dose escalation is specifically designed to minimise gastrointestinal adverse effects.

Clinical experience suggests that for many patients, gastrointestinal symptoms tend to improve with continued therapy as physiological adaptation occurs. However, some patients may experience persistent symptoms that affect quality of life. Gastrointestinal side effects are a common reason for discontinuation of GLP-1 receptor agonists, though individual susceptibility varies considerably. Factors such as dietary habits, concurrent medications, and pre-existing gastrointestinal conditions may influence symptom severity and duration.

Managing Unpleasant Burps While Taking Ozempic

Several practical strategies can help minimise bad smelling burps whilst continuing Ozempic therapy. Dietary modification represents the first-line approach and often provides symptom relief. Patients may consider reducing intake of sulphur-rich foods, including eggs, red meat, cruciferous vegetables, garlic, onions, and certain dairy products. Keeping a food diary can help identify specific triggers that exacerbate symptoms, allowing for personalised dietary adjustments.

Eating smaller, more frequent meals rather than large portions can reduce the burden on delayed gastric emptying. Patients should aim to eat slowly, chewing food thoroughly, and avoid lying down immediately after meals, which can worsen reflux and burping. Remaining upright for at least two to three hours post-meal facilitates gastric emptying and reduces the likelihood of gastro-oesophageal reflux. Adequate hydration throughout the day is important, though patients should avoid drinking large volumes of fluid with meals, as this can increase gastric distension.

Certain lifestyle modifications may also prove beneficial. Avoiding carbonated beverages, chewing gum, and drinking through straws can reduce the amount of air swallowed (aerophagia), which contributes to burping. Limiting alcohol and caffeine intake may help, as these substances can relax the lower oesophageal sphincter and promote reflux. Some patients find that probiotic supplements help optimise gut microbiome balance, though evidence for their efficacy specifically in managing GLP-1 receptor agonist-related symptoms is limited.

If symptoms persist despite dietary and lifestyle measures, patients should consult their GP or diabetes specialist nurse. In some cases, delaying dose increases or reducing to a previously tolerated dose may be appropriate under clinical guidance. Over-the-counter remedies such as simethicone (for gas relief) or antacids may provide symptomatic relief. Your pharmacist can advise on suitable options and check for any potential drug interactions.

When to Seek Medical Advice About Ozempic Side Effects

Whilst bad smelling burps are generally a benign, if unpleasant, side effect of Ozempic, certain warning signs warrant prompt medical attention. Patients should contact their GP or diabetes care team if gastrointestinal symptoms are severe, persistent, or significantly impacting quality of life and nutritional intake. Severe or persistent nausea and vomiting that prevents adequate fluid or food intake requires urgent assessment, as this may lead to dehydration and electrolyte disturbances.

Red flag symptoms that require same-day medical evaluation include: severe, persistent abdominal pain (particularly if localised to the upper abdomen or radiating to the back, which may indicate pancreatitis); vomiting blood or passing black, tarry stools (suggesting gastrointestinal bleeding); signs of dehydration such as reduced urine output, dizziness, or confusion; and unexplained weight loss beyond expected therapeutic effects. If pancreatitis is suspected, Ozempic should be discontinued immediately and urgent medical attention sought.

Patients should also seek prompt medical advice if they experience severe pain in the right upper abdomen, possibly with fever or yellowing of the skin/eyes, as GLP-1 receptor agonists have been associated with gallbladder problems including gallstones and inflammation.

Patients should also seek medical advice if they experience symptoms suggestive of severe gastroparesis (delayed gastric emptying), including persistent bloating, early satiety, recurrent vomiting of undigested food, and unintentional weight loss. Use of Ozempic is not recommended in patients with severe gastrointestinal disease, including severe gastroparesis.

It is important for patients to maintain regular follow-up appointments with their diabetes care team, typically every 3–6 months, to monitor glycaemic control, assess tolerability, and review the ongoing appropriateness of treatment. Healthcare professionals should actively enquire about gastrointestinal symptoms, as patients may be reluctant to report embarrassing symptoms such as bad smelling burps without direct questioning.

Patients can report suspected side effects to the MHRA through the Yellow Card Scheme at yellowcard.mhra.gov.uk.

Alternative Treatments If Ozempic Causes Persistent Symptoms

For patients who experience intolerable gastrointestinal side effects with Ozempic despite optimal management strategies, several alternative treatment options exist for type 2 diabetes management. The choice of alternative therapy should be individualised based on glycaemic control requirements, cardiovascular risk profile, renal function, patient preferences, and other clinical factors, in accordance with NICE guidance (NG28: Type 2 diabetes in adults: management).

Other GLP-1 receptor agonists may be considered, as individual tolerability can vary between agents within this class. Dulaglutide (Trulicity), liraglutide (Victoza), and tirzepatide (Mounjaro, a dual GIP/GLP-1 receptor agonist) have similar mechanisms of action but differ in their pharmacokinetic profiles and dosing schedules. Some patients who cannot tolerate one GLP-1 receptor agonist may tolerate another, though cross-intolerance is common. Oral semaglutide (Rybelsus) represents another option, though gastrointestinal side effects remain prevalent with this formulation.

For patients requiring injectable therapy with cardiovascular or renal benefits, SGLT2 inhibitors (sodium-glucose co-transporter-2 inhibitors) such as empagliflozin, dapagliflozin, or canagliflozin offer an alternative mechanism of action with proven cardiovascular and renoprotective effects. These agents work by increasing urinary glucose excretion and are generally well-tolerated, though they carry different side effect profiles, including increased risk of genital mycotic infections and, rarely, diabetic ketoacidosis.

DPP-4 inhibitors (dipeptidyl peptidase-4 inhibitors) such as sitagliptin, linagliptin, or saxagliptin represent oral alternatives that enhance incretin activity through a different mechanism. Whilst generally causing fewer gastrointestinal side effects than GLP-1 receptor agonists, they provide more modest glycaemic benefits and lack the weight loss and cardiovascular benefits associated with Ozempic.

For some patients, returning to or optimising conventional therapies such as metformin (if not already at maximum tolerated dose), sulphonylureas, or basal insulin may be appropriate. The decision to discontinue Ozempic should be made collaboratively between patient and healthcare provider, weighing the benefits of glycaemic control and potential cardiovascular protection against the impact of persistent side effects on quality of life. Regular review and adjustment of diabetes management remains essential to achieving optimal outcomes whilst maintaining treatment tolerability.

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