Heartburn is a recognised gastrointestinal side effect of Wegovy (semaglutide 2.4 mg), a GLP-1 receptor agonist licensed in the UK for weight management. This symptom arises primarily through delayed gastric emptying, a key mechanism by which the medication promotes satiety. Whilst heartburn affects a notable proportion of patients—particularly during initial dose titration—it is usually mild to moderate and often improves with time and appropriate management strategies. Understanding why heartburn occurs, how to manage it effectively, and when to seek medical advice can help patients continue treatment safely whilst minimising discomfort and maintaining progress towards their weight management goals.
Quick Answer: Heartburn on Wegovy occurs primarily because semaglutide delays gastric emptying, prolonging stomach contents retention and increasing the risk of acid reflux into the oesophagus.
Wegovy (semaglutide 2.4 mg) is a glucagon-like peptide-1 (GLP-1) receptor agonist licensed in the UK for weight management in adults with obesity or overweight with weight-related comorbidities. Heartburn is a common symptom of acid reflux or gastro-oesophageal reflux disease (GORD) that can occur as a side effect of this medication through several mechanisms.
The primary mechanism involves delayed gastric emptying. Semaglutide slows the rate at which food moves from the stomach into the small intestine, which is part of how it promotes satiety and reduces appetite. However, this prolonged gastric retention means stomach contents remain present for longer periods, increasing the volume in the stomach and creating conditions that may promote reflux of acidic material back into the oesophagus.
Additionally, the medication's effect on gastrointestinal motility can alter normal digestive patterns, particularly after meals. This, combined with the slower emptying, may contribute to reflux symptoms in some patients. It is important to note that while heartburn is a recognised side effect listed in the Wegovy Summary of Product Characteristics (SmPC), long-term oesophageal injury is not a recognised safety signal in the regulatory documentation. However, persistent or severe reflux symptoms should always be evaluated, as chronic gastro-oesophageal reflux disease can lead to complications if left unmanaged. The mechanism is pharmacological rather than allergic, meaning it relates directly to how the drug works rather than an immune response.
Heartburn and gastro-oesophageal reflux are among the gastrointestinal adverse effects reported in clinical trials of Wegovy. According to the Wegovy SmPC and European Public Assessment Report (EPAR), gastrointestinal side effects collectively affect a substantial proportion of patients.
In the pivotal STEP clinical trial programme, which evaluated semaglutide 2.4 mg for weight management, gastrointestinal adverse events were reported in approximately 74% of participants receiving Wegovy compared to 48% receiving placebo. While the SmPC does not provide heartburn-specific frequency data, reflux-related symptoms are reported among the gastrointestinal effects. The incidence of gastrointestinal symptoms tends to be most pronounced during the initial titration phase—the first 12–16 weeks when the dose is gradually increased from 0.25 mg to the maintenance dose of 2.4 mg weekly.
Most patients experience mild to moderate symptoms that improve over time as the body adapts to the medication. Gastrointestinal adverse events led to discontinuation in approximately 4-7% of patients in clinical trials. Individual susceptibility varies considerably: patients with pre-existing gastro-oesophageal reflux disease, hiatus hernia, or obesity-related reflux may experience symptoms, though individual responses differ. Conversely, some patients report no heartburn whatsoever throughout treatment.
It is worth noting that as weight loss progresses—one of Wegovy's intended effects—some patients actually experience improvement in reflux symptoms, as excess abdominal adiposity is a known risk factor for GORD. This creates a complex picture where initial medication-related heartburn may eventually be offset by the therapeutic benefits of weight reduction.
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Start HereEffective management of heartburn whilst taking Wegovy typically involves a combination of lifestyle modifications, dietary adjustments, and when necessary, pharmacological interventions. The first-line approach should focus on non-pharmacological strategies that reduce reflux risk without interfering with Wegovy's mechanism of action.
Dietary and lifestyle modifications form the cornerstone of management:
Eat smaller, more frequent meals rather than large portions, which reduces gastric distension and pressure
Avoid eating within 3–4 hours of lying down, allowing more time for gastric emptying before sleep
Identify and limit trigger foods such as caffeine, alcohol, chocolate, spicy foods, citrus, and high-fat meals
Remain upright after eating and consider elevating the head of the bed by 15–20 cm using blocks (not just pillows)
Avoid tight-fitting clothing around the abdomen, which can increase intra-gastric pressure
Pharmacological management may be appropriate for persistent symptoms. Over-the-counter antacids containing magnesium or calcium carbonate can provide rapid, short-term relief for occasional heartburn. For more regular symptoms, proton pump inhibitors (PPIs) such as omeprazole or lansoprazole are highly effective at reducing gastric acid production. These are available over the counter in the UK at lower doses (e.g., omeprazole 10–20 mg) or can be prescribed at higher doses if needed. A typical initial PPI trial lasts 4 weeks, after which effectiveness should be reviewed in line with NICE Clinical Guideline 184. H2-receptor antagonists like famotidine may represent an alternative option, though availability varies in the UK.
If you find yourself regularly needing over-the-counter treatments beyond a short trial period, you should consult your healthcare provider. Importantly, do not stop or reduce Wegovy without consulting your prescriber, as dose adjustments should be made systematically. If you experience side effects from Wegovy, you can report them through the MHRA Yellow Card scheme (website or app).
Whilst mild heartburn is a common and generally manageable side effect of Wegovy, certain symptoms warrant prompt medical evaluation. Patients should contact their GP or prescribing clinician if they experience:
Severe or persistent heartburn that does not respond to over-the-counter treatments or lifestyle modifications within 2–3 weeks
Difficulty or pain when swallowing (dysphagia or odynophagia), which may indicate oesophageal inflammation or stricture
Persistent nausea or vomiting, particularly if unable to keep down fluids or medications
Unintended weight loss beyond the expected therapeutic effect, or signs of malnutrition
Blood in vomit (haematemesis) or black, tarry stools (melaena), which may indicate gastrointestinal bleeding
Severe upper abdominal pain, especially if radiating to the back, which could suggest pancreatitis—a rare but serious adverse effect of GLP-1 receptor agonists
Right upper quadrant pain, fever, or jaundice, which could indicate gallbladder disease—a known risk with GLP-1 receptor agonists and rapid weight loss
Red flag symptoms requiring urgent assessment include chest pain (to exclude cardiac causes), severe persistent vomiting leading to dehydration, or any signs of gastrointestinal bleeding. Whilst heartburn itself is typically benign, these features may indicate complications requiring investigation.
Your GP may recommend further investigations if symptoms are severe or atypical. These might include upper gastrointestinal endoscopy (gastroscopy) to visualise the oesophagus and stomach lining, particularly if there are concerns about erosive oesophagitis, Barrett's oesophagus, or other structural abnormalities. NICE guidance recommends urgent referral for endoscopy for patients with dysphagia, or those aged 55 and over with weight loss and upper abdominal pain, reflux or dyspepsia.
It is also important to discuss any other medications you are taking, as some drugs can exacerbate reflux or interact with treatments for heartburn. Your prescriber can review your complete medication regimen and make appropriate adjustments to optimise both your weight management treatment and symptom control.
When heartburn remains problematic despite optimal management strategies, several options exist for adjusting treatment whilst maintaining the therapeutic goal of weight management. The decision-making process should involve shared discussion between patient and prescriber, weighing the benefits of continued Wegovy treatment against the impact of persistent symptoms on quality of life.
Dose adjustment represents the first consideration. According to the Wegovy SmPC, the recommended maintenance dose is 2.4 mg weekly. However, for patients experiencing troublesome gastrointestinal effects, a slower titration schedule or temporary reduction to 1.7 mg may improve tolerability while still providing therapeutic benefit. If intolerance persists despite these adjustments, discontinuation may be necessary. Any dose modifications should be discussed with your prescriber rather than self-adjusted.
Alternative GLP-1 receptor agonists may be considered, though all medications in this class can cause similar gastrointestinal effects due to their shared mechanism of action. Liraglutide (Saxenda), administered as a daily injection, is another licensed weight management option in the UK (NICE TA664). Some patients report different tolerability profiles between semaglutide and liraglutide, though there is no official evidence that one consistently causes less heartburn than the other. Access to these medications is typically via specialist weight management services according to NICE criteria.
Other weight management medications work through different mechanisms and may be appropriate alternatives. Orlistat, a lipase inhibitor available on NHS prescription and over the counter, does not typically cause heartburn but has different gastrointestinal side effects related to fat malabsorption. Newer agents such as tirzepatide (a dual GLP-1/GIP receptor agonist) may become available in the UK for weight management subject to MHRA authorisation and NICE appraisal.
Non-pharmacological weight management approaches should always be emphasised as foundational, regardless of medication use. Referral to specialist weight management services, dietetic support, psychological interventions for eating behaviours, and structured exercise programmes all play crucial roles. NICE guidance on obesity (CG189) recommends multicomponent interventions addressing diet, physical activity, and behaviour change as first-line management, with pharmacotherapy as an adjunct rather than standalone treatment.
Ultimately, if heartburn significantly impairs quality of life despite all reasonable adjustments, discontinuation of Wegovy may be necessary. This decision should be made collaboratively, with a clear plan for alternative weight management strategies to maintain any achieved weight loss and continue progress towards health goals.
Yes, proton pump inhibitors such as omeprazole can be taken alongside Wegovy to manage heartburn symptoms. These are available over the counter at lower doses or by prescription, and a typical initial trial lasts 4 weeks under healthcare provider guidance.
Most patients experience mild to moderate heartburn that improves as the body adapts to Wegovy, particularly after the initial 12–16 week titration phase. Additionally, as weight loss progresses, some patients find reflux symptoms improve due to reduced abdominal adiposity.
Do not stop or adjust Wegovy without consulting your prescriber. Severe or persistent heartburn warrants medical evaluation, and your healthcare provider can recommend management strategies, dose adjustments, or alternative treatments whilst maintaining your weight management goals.
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