Mounjaro Side Effects

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Answer the side-effect intent for mounjaro without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.

Part of diabetes & weight management side effects.

What is Mounjaro?

Mounjaro contains the active ingredient Tirzepatide.

• Active ingredient — Tirzepatide
• Registration number — 57/21.13/0821; 57/21.13/0822; 57/21.13/0823; 57/21.13/0824
• Registration holder — Eli Lilly (S.A.) (Pty) Ltd

It is approved for:

• on its own when you can’t take metformin (another diabetes medicine)
• with other medicines for diabetes when they are not enough to control your blood sugar levels. These other medicines may be medicines taken by mouth and/or insulin given by injection. MOUNJARO is also used together with diet and exercise for weight loss and to help keep the weight under control in adults, who have:
• a BMI of 30 kg/m² or greater (obesity) or
• a BMI of at least 27 kg/m² but less than 30 kg/m² (overweight) and weight-related health problems (such as prediabetes, type 2 diabetes, high blood pressure, abnormal levels of fats in the blood, breathing problems during sleep called ‘obstructive sleep apnoea’ or a history of heart attack, stroke or blood vessel problems) BMI (Body Mass Index) is a measure of your weight in relation to your height. It is important to continue to follow the advice on diet and exercise given to you by your doctor, pharmacist or nurse

Common side effects of Mounjaro

Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.

Reported side effects

• Inflamed pancreas (acute pancreatitis) which could cause severe pain in the stomach and back which does not go away. You should see a doctor immediately if you experience such symptoms
• These are all serious side effects. You may need urgent medical attention. Tell your doctor if you notice any of the following: Very common (may affect more than 1 in 10 people)
• Feeling sick (nausea)
• Diarrhoea
• Stomach (abdominal) pain reported in patients treated for weight management
• Being sick (vomiting) reported in patients treated for weight management
• Constipation reported in patients treated for weight management These side effects are usually not severe. They are most common when first starting MOUNJARO but decrease over time in most patients
• Low blood sugar (hypoglycaemia) is very common when MOUNJARO is used with medicines that contain a sulphonylurea and/or insulin. If you are using a sulphonylurea or insulin for type 2 diabetes, the dose may need to be lowered while you use MOUNJARO. Symptoms of low blood sugar may include headache, drowsiness, weakness, dizziness, feeling hungry, confusion, irritability, fast heartbeat and sweating. Your doctor should tell you how to treat low blood sugar. Common (may affect up to 1 in 10 people)
• Low blood sugar (hypoglycaemia) when MOUNJARO is used for type 2 diabetes with both metformin and a sodium-glucose co-transporter 2 inhibitor (another diabetes medicine)
• Allergic reaction (hypersensitivity) (e.g., rash, itching, and eczema)
• Dizziness reported in patients treated for weight management
• Low blood pressure reported in patients treated for weight management
• Feeling less hungry (decreased appetite) reported in patients treated for type 2 diabetes
• Stomach (abdominal) pain
• Being sick (vomiting) – this usually goes away over time
• Indigestion (dyspepsia)
• Constipation
• Bloating of the stomach
• Burping (eructation)
• Gas (flatulence)
• Reflux or heartburn (also called gastroesophageal reflux disease – GERD) – a disease caused by stomach acid coming up into the tube from your stomach to your mouth
• Hair loss reported in patients treated for weight management
• Feeling tired (fatigue)
• Injection site reactions (e.g. itching or redness)
• Fast pulse
• Increased levels of pancreatic enzymes (such as lipase and amylase) in blood. Uncommon (may affect up to 1 in 100 people)
• Low blood sugar (hypoglycaemia) when MOUNJARO is used with metformin for type 2 diabetes
• Gallstones
• Inflammation of the gallbladder
• Weight loss reported in patients treated for type 2 diabetes
• Injection site pain
• Increased calcitonin levels in blood

Serious side effects and warning signs

This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.

General warning signs that apply to any medicine

How long can side effects last?

How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.

• Settling effects — mild effects that ease over the first days or weeks of use
• Ongoing effects — effects that continue while the product is being used and improve after stopping
• Persistent effects — effects that continue after stopping and need medical review
• Delayed effects — effects that appear after weeks or months rather than immediately

Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.

Factors that may affect side effects

The approved leaflet identifies the following cautions and factors.

Do not use it at all if

• are allergic to tirzepatide or to any of the other ingredients of MOUNJARO (listed in section 6)
• or any of your family have ever had a type of thyroid cancer called medullary thyroid carcinoma (MTC) or if you have an endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2)

Use with care, and tell your doctor, if

• you or any of your family have ever had a type of thyroid cancer called medullary thyroid carcinoma (MTC) or if you have an endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2)
• you have severe problems with food digestion or food remaining in your stomach for longer than normal (including severe gastroparesis)
• you have ever had pancreatitis (inflammation of the pancreas which may cause severe pain in the stomach and back which does not go away)
• you have a problem with your eyes (diabetic retinopathy or macular oedema)
• you are using a sulphonylurea (another diabetes medicine) or insulin for your diabetes, as low blood sugar (hypoglycaemia) can occur. Your doctor may need to change your dose of these other medicines to reduce this risk. When starting treatment with MOUNJARO, in some cases you may experience loss of fluids/dehydration, e.g. due to vomiting, nausea and/or diarrhoea, which may lead to a decrease in kidney function. It is important to avoid dehydration by drinking plenty of fluids. Contact your doctor if you have any questions or concerns. Children and adolescents MOUNJARO should not be given to children and adolescents under 18 years of age because it has not been studied in this age group

Pregnancy and breastfeeding

• If you are pregnant or breastfeeding your baby, please consult your doctor, pharmacist or other healthcare professional for advice before taking MOUNJARO
• Pregnancy If you are pregnant, think you may be pregnant or are planning to have a baby, ask your doctor for advice before using MOUNJARO
• MOUNJARO should not be used during pregnancy as the effects on an unborn child are not known
• Therefore, it is recommended to use contraception while using this medicine
• Breastfeeding You should not breastfeed your infant when taking MOUNJARO
• It is unknown whether tirzepatide passes into breast milk

Interactions and medicines to check

The approved leaflet names these interactions.

• Tell your doctor, pharmacist or nurse if you are using, have recently used or might use any other medicines
• (this includes complementary or traditional medicines)

What to do if you experience side effects

If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.

If the symptom is severe or frightening

Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.

If the symptom is mild but bothering you

• Write down what the symptom is, when it started, and how it relates to when you take the product
• Check the leaflet that came with the product to see whether the symptom is listed
• Speak to your pharmacist — for many questions this is the fastest route to a useful answer
• Contact the prescriber if the symptom is affecting your daily life or is not settling

You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.

When to seek urgent medical help

Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.

Get same-day medical advice if you have

• A high fever, or a rash together with feeling generally unwell
• Yellowing of the eyes or skin, or unusually dark urine
• Unusual bruising or bleeding that you cannot explain
• Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
• A sudden change in mood, or thoughts of harming yourself
• Any symptom that is rapidly getting worse

How to report a suspected side effect in South Africa

South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.

Who can report

Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.

What to have ready

• The name of the product, its strength and form, and the batch number if you have it
• Why it was being used, and when it was started and stopped
• What the suspected reaction was, when it began, and how long it lasted
• Any other medicines, supplements or remedies being used at the same time
• Basic details about the person affected — age and sex are usually enough

How to report

SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.

• SAHPRA Health Products Vigilance — the main vigilance and reporting hub
• SAHPRA e-Services — current adverse reaction reporting access

For a fuller walkthrough see how to report an adverse drug reaction.

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