Mounjaro side effects: a complete overview and what to do about them

GLP-1 medications like Mounjaro (tirzepatide) and Zepbound help many people lose weight and regulate their blood sugar. But like any medication, they can cause side effects — especially in the first few weeks and when increasing the dose. In this overview we list the most common side effects and give practical tips to manage them better.

Important: this article is informational and does not replace medical advice. Do you have severe or persistent symptoms? Always contact your doctor.

The most common side effects

1. Gastrointestinal complaints

Nausea, constipation, diarrhoea and a feeling of fullness are the most frequently reported side effects. They occur because GLP-1 medication slows down gastric emptying. Usually these complaints ease as your body adjusts to the dose.

• Eat smaller portions, slowly and spread throughout the day.
• Avoid fatty, fried and heavily spiced food in the first days after an injection.
• Keep enough fibre (such as psyllium) and fluids to prevent constipation.

2. Fatigue and low energy

Many users feel tired at the start. This is often due to the sharply reduced calorie intake: eating less also means fewer vitamins and minerals such as B12, magnesium and iron. Read more about fatigue on GLP-1 and what helps.

3. Hair loss

Hair loss on Mounjaro is usually not a direct effect of the drug itself, but of rapid weight loss and shortages of protein and micronutrients (telogen effluvium). It is almost always temporary. Read what exactly happens and what you can do about it.

4. Nausea

Nausea is the most common reason people stop. It is often manageable by adjusting eating and drinking habits. Don't force yourself to eat when you're full, and choose light, protein-rich food. Read our full guide on nausea on Mounjaro.

5. Muscle loss

With rapid weight loss you lose not only fat but also muscle mass. Enough protein and strength training are essential to limit this. Read more about preserving muscle on GLP-1.

Why nutrition matters so much

Many of the unpleasant side effects — fatigue, hair loss, brittle nails — are linked to the simple fact that you eat much less. As a result you take in less protein, fibre, vitamins and minerals, exactly when your body is working hard. A targeted supplement like Mayntain Daily is designed to support these gaps, with ingredients including collagen, psyllium, magnesium, B12, biotin and zinc.

When to see a doctor

Contact your doctor in case of persistent vomiting, severe abdominal pain (a possible sign of pancreatitis), signs of dehydration, or any other severe or persistent symptoms.

Food supplements are not a substitute for a varied diet, a healthy lifestyle or medical advice. When in doubt, consult your doctor or pharmacist.