Burping, Reflux and Indigestion on GLP-1 Medication

Burping, sulphur or "eggy" burps, heartburn, acid reflux and indigestion are common side effects of GLP-1 medicines such as Mounjaro (tirzepatide) and Wegovy (semaglutide). The UK product information for both lists burping (eructation), indigestion (dyspepsia) and gastro-oesophageal reflux disease as common side effects. They are thought to be linked mainly to slower stomach emptying, which keeps food in the stomach for longer. For most people, these symptoms are worst after starting treatment or increasing the dose and ease with time. Simple changes to how and when you eat often help, and pharmacists can advise on short-term remedies.

Understanding the different symptoms

These symptoms often overlap, but it helps to know what each term means, because they can respond to slightly different measures.

The NHS notes that reflux can also cause a recurring cough or hiccups, a hoarse voice, bad breath, bloating and feeling sick. Symptoms are often worse after eating, when lying down and when bending over.

How common are these symptoms?

The UK Summaries of Product Characteristics (SmPCs) group side effects by how often they occurred in clinical trials.

"Common" means these effects were reported in between 1 in 100 and 1 in 10 people. Frequency categories can change as product information is updated, so check the current SmPC or patient leaflet for your medicine. Oral GLP-1 medicines can cause similar symptoms; see our guide to oral GLP-1 side effects.

Why GLP-1 medicines cause burping and reflux

Slower stomach emptying

GLP-1 medicines slow the rate at which food leaves the stomach. This is part of how they help you feel full and eat less, but it also means:

• Food stays in the stomach longer, so you may feel full, heavy or bloated
• A fuller stomach puts more pressure on the valve at the top of the stomach, making reflux more likely
• Gas produced during digestion may be released by burping rather than passing further along the gut

Sulphur burps

Sulphur burps smell of rotten eggs because of sulphur-containing gases, particularly hydrogen sulphide. A plausible explanation, often given by clinicians, is that food sitting longer in the stomach and upper gut, especially protein-rich food, is broken down in ways that release more of these gases. Changes in gut bacteria may also play a part. However, this explanation has not been well studied, and sulphur burps are not listed under that name in the SmPCs.

Eating patterns

Eating too quickly, eating past fullness, or eating large meals when your stomach is emptying slowly can all make symptoms worse. Many people find that a portion they used to eat comfortably now causes discomfort.

Other factors

The NHS lists several factors that can cause or worsen heartburn and indigestion in anyone, including:

• Coffee, tomatoes, alcohol, chocolate, and fatty or spicy foods
• Being overweight
• Smoking
• Stress and anxiety
• Some medicines, such as anti-inflammatory painkillers like ibuprofen
• A hiatus hernia
• A stomach ulcer or stomach infection

These can combine with the effects of a GLP-1 medicine.

When symptoms tend to happen

Many people notice a pattern:

• In the first one to three days after a weekly injection, when gastrointestinal effects often peak
• After each dose increase, as the body adjusts to a higher dose
• After large, rich or late meals
• At night or when lying down, as stomach contents can move up more easily

The Wegovy SmPC notes that indigestion, burping, reflux, bloating and wind were mainly seen during the dose escalation period. Many people find symptoms settle once they reach a stable dose.

Practical ways to ease symptoms

These self-care measures draw on NHS advice for heartburn and indigestion, adapted for life on a GLP-1. They are not a substitute for advice from your prescriber or pharmacist.

How you eat

• Eat smaller, more frequent meals. The NHS recommends this for heartburn, and it suits the reduced appetite many people have on GLP-1 medicines.
• Eat slowly and chew well. Put your cutlery down between mouthfuls.
• Stop as soon as you feel full. Fullness signals can arrive later than you expect.
• Avoid drinking large volumes with meals, which can increase stomach fullness. Sip fluids between meals instead.
• Stay upright after eating for at least an hour or two. A gentle walk may help.

When you eat

• Avoid eating within 3 to 4 hours of going to bed, as the NHS advises. This is particularly important on a GLP-1 because food stays in your stomach longer.
• Make your evening meal your lightest, if this suits you.

What you eat and drink

Common triggers include:

• Fatty, fried or very rich food
• Large portions of red meat or eggs, which some people link to sulphur burps
• Cruciferous vegetables such as broccoli, cabbage and cauliflower, and beans, which can increase gas
• Fizzy drinks, including sparkling water
• Alcohol
• Coffee and strong tea
• Spicy food, tomatoes, citrus and chocolate
• Sugar alcohols in sugar-free products, which can cause bloating and wind
• Some protein shakes and bars

You do not need to cut all of these out. Keep a simple food and symptom diary for two or three weeks to spot your own triggers. Our guide to foods that can worsen GLP-1 side effects goes into more detail, and what to eat on GLP-1 medication offers balanced meal ideas.

Protein without the burps

Protein is important during weight loss, but protein-heavy meals are sometimes linked to sulphur burps. Spreading protein across the day in smaller amounts, choosing leaner sources, and trying different types (for example, fish, poultry, Greek yoghurt, tofu or lentils) may help. See our guide to protein on GLP-1 medication.

At night

• Raise the head of your bed by around 10 to 20cm using sturdy blocks or books under the legs, as the NHS suggests. Extra pillows are not recommended because they can increase pressure on your belly.
• Sleeping on your left side is suggested by some clinicians for reflux, although evidence is limited.
• Avoid tight clothing around your waist.

Other lifestyle factors

• Stop smoking, if you smoke.
• Keep alcohol within recommended limits or avoid it.
• Find ways to manage stress.
• Avoid ibuprofen and aspirin unless prescribed, as the NHS notes these can make indigestion worse.

Pharmacy treatments

A pharmacist can recommend medicines for heartburn and indigestion. According to the NHS, options include:

The NHS advises that antacids and alginates should ideally be taken with food or soon after eating, and should not be taken regularly for long periods. If you find you need them most days, see your GP.

Always tell the pharmacist that you take a GLP-1 medicine and list all your other medicines. Bismuth-containing products, sometimes suggested for sulphur burps, are not suitable for everyone, so seek advice before using them.

Treatment from your GP or prescriber

If self-care and pharmacy medicines are not enough, your GP may:

• Prescribe a PPI such as omeprazole or lansoprazole, usually for four or eight weeks, as the NHS describes
• Suggest an H2 receptor antagonist such as famotidine if a PPI does not help
• Test for Helicobacter pylori, a stomach infection that can cause indigestion
• Refer you for a gastroscopy if you have warning signs or symptoms do not improve

Your GLP-1 prescriber may consider slowing your titration or reducing your dose. The Wegovy SmPC states that in case of significant gastrointestinal symptoms, prescribers can consider delaying dose escalation or lowering to the previous dose. Do not change your dose without speaking to them. Our guides to the Mounjaro dosing schedule and Wegovy dosing schedule explain the usual steps.

Reflux, slow stomach emptying and anaesthesia

Because GLP-1 medicines slow stomach emptying, the SmPCs warn that cases of pulmonary aspiration (stomach contents entering the lungs) have been reported in people taking these medicines who had general anaesthesia or deep sedation. The MHRA's patient guidance also highlights this risk.

If you are having surgery, an endoscopy or any procedure under sedation, tell the team you take a GLP-1 medicine, well in advance. They may give specific instructions. Read more in our guide to GLP-1 medication, surgery and anaesthesia.

Could it be something else?

Indigestion and upper tummy discomfort on a GLP-1 are usually side effects, but sometimes symptoms point to something more serious.

Pancreatitis

In January 2026, the MHRA strengthened warnings about acute pancreatitis across all GLP-1 medicines, noting rare necrotising and fatal cases. The MHRA highlighted that early symptoms such as abdominal pain, nausea and vomiting can be mistaken for common side effects. The warning sign is severe, persistent abdominal pain that may radiate to the back. Read our guide to GLP-1 medication and pancreatitis.

Gallbladder problems

Pain in the upper right of the tummy, especially after fatty meals, sometimes spreading to the right shoulder, may suggest gallstones. Gallbladder problems are a recognised side effect of GLP-1 medicines. See our guide to GLP-1 medication and gallbladder problems.

Ulcers and other conditions

The NHS lists warning signs with indigestion that need a GP, including difficulty swallowing, being sick repeatedly, iron deficiency anaemia, a lump in your stomach, and blood in vomit or poo. Unintentional weight loss is also a warning sign, but on a GLP-1 this can be hard to judge, so mention any weight loss that seems faster than expected, or any of the other symptoms, to your GP.

Heart problems

Chest pain is not always heartburn. Pain that feels tight, heavy or crushing, spreads to the arm, jaw, neck or back, or comes with breathlessness, sweating or feeling sick could be a heart attack. Call 999.

Living with symptoms day to day

For most people, burping and reflux are manageable and improve over time. A few further practical tips:

• Carry antacid or alginate tablets if a pharmacist has said they are suitable for you
• Plan lighter meals around the days after your injection if that is when symptoms peak
• Keep sugar-free mints or chewing gum for bad breath, but watch for sugar alcohols that may cause wind
• Brush your teeth and rinse your mouth after episodes of reflux to protect tooth enamel
• If social situations involving food feel stressful, choose smaller portions and eat slowly; it is fine to leave food

Our guide to nausea on GLP-1 medication covers related symptoms.

Burping, reflux and your other medicines

GLP-1 medicines slow stomach emptying, which can affect how quickly some tablets and capsules are absorbed. For most medicines this is not important, but it is worth a conversation with a pharmacist if you take medicines where timing or blood levels matter.

Antacids can also reduce the absorption of some medicines, including certain antibiotics, iron and thyroid medicines, if taken at the same time. A pharmacist can advise on spacing doses. If you take medicines for diabetes alongside a GLP-1 and are eating much less because of indigestion, ask your diabetes team whether any adjustment is needed to reduce the risk of low blood sugar. Our guide to GLP-1 medication interactions explains more.

Finding the right support

Good follow-up makes side effects easier to manage. If you are comparing regulated online providers, our provider comparison sets out how each service handles reviews and side-effect support. We do not rank providers, and only a prescriber can decide on your treatment. For more background, see the Mounjaro side effects guide, the Mounjaro burping page, the Mounjaro indigestion page, and our hub on weight-loss injections.

Reporting side effects

If you have burping, reflux, indigestion or any other suspected side effect from a GLP-1 medicine, you can report it to the MHRA via the Yellow Card scheme, online or using the app. Your report helps regulators understand how medicines affect people in everyday use.

When to speak to a professional

Speak to a pharmacist or your prescriber if:

• Burping, reflux or indigestion is affecting your sleep, eating or quality of life
• You need antacids or alginates most days
• Symptoms flare badly after every injection or dose increase

See your GP if:

• You have heartburn most days, or lifestyle changes and pharmacy medicines are not helping
• You have difficulty swallowing or food feels stuck
• You keep being sick
• You feel a lump in your stomach, or have been told you have iron deficiency anaemia
• You are losing weight much faster than expected

Call NHS 111 or get urgent help if:

• You cannot keep fluids down or have signs of dehydration, such as dark urine, peeing less, dizziness or a dry mouth
• Your symptoms are getting rapidly worse

Call 999 or go to A&E if:

• You have severe, persistent abdominal pain, especially if it spreads to your back, with or without vomiting, which may be acute pancreatitis. Stop your GLP-1 and tell staff you take it.
• You vomit blood or material that looks like coffee grounds, or pass black, tarry stools
• You have chest pain that feels tight or heavy, or spreads to your arm, jaw, neck or back, or comes with breathlessness or sweating
• You have pain in the upper right of your tummy with a high temperature, or yellowing of the skin or eyes (jaundice)

If you are struggling with your mental health or having thoughts of suicide, call NHS 111 (option 2 for mental health in many areas), contact Samaritans free on 116 123, or call 999 in an emergency.