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Mounjaro Side Effects Explained

While Mounjaro is effective for weight loss, it can cause side effects. Here is a complete guide on what to expect and how to manage them.

Like all medications, Mounjaro (Tirzepatide) can cause side effects, although not everyone gets them. Most side effects are mild to moderate and typically occur when you first start treatment or when your dose is increased.

Key Fact: Most side effects subside within a few weeks as your body adjusts to the medication.

Very Common Side Effects

These may affect more than 1 in 10 people:

Nausea (Feeling Sick)

The most common side effect. Usually improves with time.

Tip: Eat smaller, more frequent meals.

Diarrhoea

Can cause dehydration.

Tip: Drink plenty of water and avoid fatty foods.

Vomiting

Less common than nausea but can happen.

Tip: Avoid lying down immediately after eating.

Constipation

Due to slower digestion.

Tip: Increase fibre intake and stay hydrated.

Other Common Side Effects (Up to 1 in 10)

  • Abdominal pain
  • Indigestion (Dyspepsia)
  • Fatigue (Tiredness)
  • Injection site reactions (redness/itching)
  • Decreased appetite
  • Bloating
  • Reflux or heartburn
  • Burping (Eructation)

Serious Side Effects

Serious side effects are rare but require immediate medical attention. Stop using Mounjaro and contact your doctor or call 111 immediately if you experience:

Severe Stomach Pain (Pancreatitis)

Severe pain in your stomach area that will not go away, with or without vomiting. The pain may radiate to your back.

Allergic Reactions

Swelling of your face, lips, tongue or throat, problems breathing or swallowing, severe rash or itching.

Gallbladder Problems

Pain in your upper stomach (right side), fever, yellowing of skin or eyes (jaundice), or clay-colored stools.

How to Manage Side Effects

1

Hydrate, Hydrate, Hydrate

Dehydration makes nausea and constipation worse. Aim for 2-3 litres of water daily.

2

Adjust Your Diet

Avoid fried, greasy, or very sweet foods. Eat smaller portions and eat slowly. Stop eating when you feel full.

3

Don't Rush the Dose

Follow the titration schedule (2.5mg → 5mg etc.). Moving up too fast increases side effect risks significantly.

Mounjaro Resources

Compare PricesWhat is Mounjaro?Dosage Guide

Need Medical Advice?

If you are concerned about side effects, always consult your prescriber or GP.

Visit NHS 111 Online

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