Why Mounjaro can give you heartburn and how to treat it

Mounjaro pens have quickly gained recognition for their effectiveness in promoting weight loss (1). This weight loss injection is a game-changer for many, curbing food cravings and improving overall health. But, like all weight loss medications, it’s not without side effects.

One of the most common complaints with Mounjaro is heartburn or acid reflux. While it can be frustrating, the good news is that it’s usually temporary and can be managed with simple changes or treatments. If you’re thinking of stopping Mounjaro weight loss injections because of heartburn, let us tell you what you can do to get it under control and protect that weight loss journey.

Why does Mounjaro cause heartburn?

Heartburn happens when stomach acid flows backwards along the digestive tract into the oesophagus, causing a burning sensation in the chest or throat (2). Mounjaro injections can trigger heartburn because this drug slows down how quickly food leaves the stomach (3).

This slower digestion means food hangs around in your stomach longer, so the body produces more stomach acid to help digest it. The extra acid can sometimes escape upward, causing that uncomfortable burning feeling. Delayed gastric emptying can also contribute to nausea and vomiting, two other common Mounjaro side effects (4).

How can you relieve Mounjaro heartburn?

For most people, Mounjaro heartburn improves after the first few weeks. In the meantime, here are some tried-and-tested ways to manage it:

1. Change your daily habits

Small changes can make a big difference when it comes to heartburn:

• Eat smaller, more frequent meals: The larger your meals, the longer they take to digest and the more stomach acid your body produces. Instead of three large meals, try eating smaller portions throughout the day to reduce pressure on your stomach.
• Identify and avoid trigger foods: Spicy dishes, citrus fruits, and caffeine can all make heartburn worse. If certain foods seem to set it off, try cutting them out of your diet. Mounjaro and alcohol consumption should also be limited, as it is known to worsen side effects.
• Don’t lie down right after eating: Heartburn often worsens when lying down. Stay upright for at least 2 hours after eating to give your stomach time to digest. This might mean altering your evening meal times to stop you from getting acid reflux while trying to sleep.
• Elevate your head when sleeping: If you’re still suffering from acid reflux at night, use extra pillows or a wedge pillow to keep your upper body slightly higher than your stomach. This helps prevent acid from creeping up your oesophagus while you sleep.

2. Medications for heartburn

If lifestyle changes aren’t enough, medications can help manage heartburn symptoms. Your best option is to take a short course of Omeprazole or Lansoprazole for the first 1-2 weeks after starting Mounjaro, which can give your body time to adjust to the weight loss drug.

Omeprazole and Lansoprazole are protein pump inhibitors (PPIs), which work by reducing the amount of acid your stomach produces (5). With less stomach acid, there’s a lower chance of heartburn. You can purchase Lansoprazole, Omeprazole, and other acid reflux medications through our online pharmacy, and we’ll ship the medication directly to your door.

However, these drugs may not be suitable if you are allergic to PPIs, have liver problems, or are due to have an endoscopy (6)(7). If you can’t or don’t want to take PPIs, over-the-counter antacids like Gaviscon or Rennie neutralise stomach acid for quick relief.

What if Mounjaro heartburn doesn’t go away?

Heartburn might feel like a frustrating hurdle, but it’s important to remember that it and other Mounjaro side effects are often temporary.

How long do Mounjaro side effects last? Well, most people find they settle within a few days or weeks of starting treatment, so be patient - heartburn shouldn’t be enough reason to stop taking this weight loss drug. While the initial weeks can be irritating, plenty of lifestyle changes and medical options offer relief during the initial adjustment process.

If the discomfort persists or acid reflux worsens, talk to your doctor or contact us at Oxford Onlne Pharmacy. You may need to alter your Mounjaro dose, or we can help you find the right over-the-counter products or medications to ease your symptoms.

Can you prevent heartburn when increasing your dose?

Heartburn and other Mounjaro side effects, like nausea, are often a problem when first starting treatment. However, they can also temporarily worsen if you increase your Mounjaro injection dose. This is because your stomach needs time to adjust to the changes in digestion speed.

To minimise discomfort during dose adjustments, follow these tips:

• Stay consistent with lifestyle tips: Stick to smaller meals, avoid foods that trigger heartburn, don’t mix Mounjaro and alcohol, and try to avoid lying down after eating.
• Plan ahead with remedies: Have antacids like Rennie and Gaviscon on hand before increasing your dose of Mounjaro weight loss injections.
• Give your body time: Most side effects improve within a week or two after a dose change. Be patient, and speak to a doctor or us at Oxford Online Pharmacy if symptoms worsen.

If you have concerns about managing heartburn when starting treatment or increasing your dose, contact our healthcare team for advice. You can also purchase Lansoprazole or Omeprazole through our online pharmacy to help ease the unpleasant side effects while your body adjusts to the drug.

Together, we can keep your Mounjaro weight loss journey on track—without suffering from uncomfortable Mounjaro side effects.

Citations

1. Gettman L. New Drug: Tirzepatide (MounjaroTM). The Senior Care Pharmacist [Internet]. 2023 Feb 1;38(2):50–62.
2. Schachter H. Indigestion and Heartburn [Internet]. 3rd ed. Walker HK, Hall WD, Hurst JW, editors. PubMed. Boston: Butterworths; 1990.
3. Jalleh RJ, Plummer MP, Marathe CS, Umapathysivam MM, Quast DR, Rayner CK, et al. Clinical Consequences of Delayed Gastric Emptying With GLP-1 Receptor Agonists and Tirzepatide. The Journal of Clinical Endocrinology & Metabolism [Internet]. 2024 Oct 17 [cited 2024 Nov 25]
4. Lin F, Yu B, Ling B, Lv G, Shang H, Zhao X, et al. Weight loss efficiency and safety of tirzepatide: A Systematic review. PloS One [Internet]. 2023;18(5):e0285197.
5. Proton Pump Inhibitors [Internet]. PubMed. Bethesda (MD): National Institute of Diabetes and Digestive and Kidney Diseases; 2012.
6. NHS. Who can and cannot take omeprazole [Internet]. nhs.uk. 2021.
7. NHS. Lansoprazole: medicine to lower stomach acid [Internet]. nhs.uk. 2018. ‌