Mounjaro®

Mounjaro is a medicine containing the active substance tirzepatide. It is used for two medical purposes:

1. Weight loss and weight maintenance in adults with obesity (BMI ≥ 30) or overweight (BMI 27–30) with weight-related health issues, such as high blood pressure, sleep apnea, or elevated cholesterol.
2. Treatment of type 2 diabetes in adults when diet and exercise alone are insufficient to control blood sugar.

Source: EMA SmPC Mounjaro (NL, 2023).

Below is concise usage information for the pen. Always read the package leaflet or consult your doctor/pharmacist for guidance.

Important Information About the Pen

• Each pen contains one fixed dose.
• You can inject 4 times with one pen (once per week).
• After 4 injections, the pen locks automatically.
• Some residual liquid remains; this is not a full dose.

Check Before Each Injection

1. Attach a new needle to the pen.
2. Turn the back of the pen 2 clicks until the first line appears in the window.
3. Press the back until a ‘0’ appears in the display.
4. If a drop appears at the needle, the pen is ready for use.
5. If no drop appears, repeat the steps; if this persists after 2 attempts, replace the needle and repeat the check.
6. If a drop appears, turn the pen fully until ‘1’ shows in the display and administer the dose.

Storage

• Store in the refrigerator (2–8 °C), do not freeze, and protect from light.
• After opening: can be stored at room temperature (max. 30 °C) for up to 30 days.

Source: Mounjaro Package Leaflet (NL, 2023).

Tirzepatide is the active substance in Mounjaro, produced by Eli Lilly. It is an incretin mimetic, activating both the GIP and GLP-1 receptors. These receptors play a role in insulin release after meals, reducing glucagon secretion, and influencing appetite and satiety. Through this combined action, tirzepatide helps regulate blood sugar and supports weight loss and maintenance for the appropriate indications. Source: SmPC §5.1.

Mounjaro contains tirzepatide, a substance that mimics two natural hormones in your body: GIP and GLP-1. These hormones are produced in the intestines after meals and help the body utilize sugar from food effectively. They prompt the pancreas to produce more insulin when blood sugar rises and reduce the amount of sugar released by the liver into the blood.

Summary of Action

• Lowering blood sugar levels when they are too high;
• Slowing gastric emptying, so food stays in the stomach longer;
• Providing a feeling of fullness, leading to reduced food intake;
• Supporting weight loss and weight maintenance in obesity or overweight.

The effect builds gradually during treatment. Mounjaro only lowers blood sugar when it is too high. Source: SmPC §5.1.

Results After 12 Months (SURPASS-3)

The table below shows the average weight change and the percentage of participants achieving at least 5%, 10%, or more than 15% weight loss after 52 weeks of Mounjaro treatment, alongside diet and exercise.

Source: SmPC §5.1, Table 6.

Mounjaro is a prescription-only medicine. It is not available over the counter and can only be dispensed with a doctor’s prescription. Dispensing occurs through a pharmacy. Online purchase without a prescription or outside a pharmacy is not permitted. Source: SmPC §4.1.

The price of Mounjaro is determined by the pharmacy and may vary depending on strength and dosage. For current costs, contact your pharmacy. (The SmPC does not contain pricing information.)

Mounjaro can be prescribed to adults with:

• BMI ≥ 30 (obesity), or
• BMI 27–30 (overweight) with at least one weight-related condition (e.g., hypertension, dyslipidemia, or sleep apnea),

and to adults with type 2 diabetes when diet and exercise alone are insufficient. Source: SmPC §4.1.

Mounjaro is available only by prescription. A BIG-registered doctor assesses whether you meet the medical criteria and can then issue a prescription. Source: SmPC §4.1.

Mounjaro may be reimbursed in some cases for the treatment of type 2 diabetes when other treatments are insufficiently effective. For weight loss, Mounjaro is usually not covered by the basic insurance package. Check with your health insurer or pharmacy. (The SmPC does not contain reimbursement information.)

Mounjaro contains tirzepatide, a substance similar to the hormones GIP and GLP-1, which are released after a meal. They help the body utilize sugar from food effectively. They prompt the pancreas to produce more insulin when blood sugar rises and reduce the amount of sugar released by the liver into the blood.

Summary of Action

• Lowering blood sugar levels when they are too high;
• Slowing gastric emptying (food stays in the stomach longer);
• Providing a feeling of fullness (less appetite);
• Supporting weight loss and weight maintenance.

The effect builds gradually; Mounjaro only lowers blood sugar when it is too high. Source: SmPC §5.1.

Mounjaro is a pre-filled pen with a fixed strength per pen. Below is the composition as stated in the official product information.

• Active substance: tirzepatide.
• Other excipients: sodium chloride, dibasic sodium phosphate heptahydrate, and water for injection.

Source: SmPC.

Mounjaro is administered as a subcutaneous injection (under the skin). Below, you can read where to inject and what to consider during first use.

• Do not inject into a vein or muscle.
• Suitable injection sites:
  • Front of the thigh
  • Abdomen (front center)
  • Upper arm
• Have your doctor or nurse demonstrate how to use the pen before first use.

Source: Package Leaflet (NL, 2023).

Always use Mounjaro as explained by your doctor or pharmacist and read the package leaflet. Practical instructions:

• Administer the injection once a week, preferably on the same day.
• Rotate injection sites (abdomen, thigh, upper arm).
• Missed dose: administer within 4 days; otherwise, skip and continue as scheduled. Do not take a double dose.
• Storage: in the refrigerator (2–8 °C), do not freeze; after opening, can be stored at room temperature (max. 30 °C) for up to 30 days.

Source: Package Leaflet (NL, 2023).

Mounjaro and Zepbound both contain tirzepatide and are produced by Eli Lilly.

Application

Mounjaro: weight loss/weight maintenance and type 2 diabetes. Zepbound: weight loss/weight maintenance.

Active Substance and Class

Both: tirzepatide (GIP + GLP-1 receptor agonist).

Dosage/Administration Frequency

Both: once weekly (titration per SmPC).

Registration Status/Availability

• Mounjaro: available in the Netherlands/EU.
• Zepbound: not available in the Dutch market.

Sources: SmPC Mounjaro, EMA.

Application

Mounjaro: weight loss/weight maintenance and type 2 diabetes. Saxenda: weight loss/weight maintenance.

Active Substance and Class

Mounjaro: tirzepatide (GIP + GLP-1). Saxenda: liraglutide (GLP-1).

Dosage/Administration Frequency

• Mounjaro: 1× per week (2.5–15 mg; titration).
• Saxenda: 1× per day (0.6–3 mg; titration).

Sources: SmPC Mounjaro, EMA.

Application

Mounjaro: weight loss/weight maintenance and type 2 diabetes. Ozempic: type 2 diabetes (not registered for weight loss).

Active Substance and Class

Mounjaro: tirzepatide (GIP + GLP-1). Ozempic: semaglutide (GLP-1).

Dosage/Administration Frequency

Both: 1× per week (titration per SmPC).

Sources: SmPC Mounjaro, EMA.

Application

Mounjaro: weight loss/weight maintenance and type 2 diabetes. Wegovy: weight loss/weight maintenance.

Active Substance and Class

Mounjaro: tirzepatide (GIP + GLP-1). Wegovy: semaglutide (GLP-1).

Dosage/Administration Frequency

Both: 1× per week (titration per SmPC).

Sources: SmPC Mounjaro, EMA.

Possible Side Effects

• Nausea
• Diarrhea
• Decreased appetite
• Vomiting
• Constipation
• Abdominal pain
• Indigestion (heartburn)
• Flatulence or belching
• Reflux (backflow of stomach acid)
• Fatigue
• Injection site reactions (itching, redness, or pain)

Other Reported Side Effects

• Dizziness
• Rapid heartbeat (tachycardia)
• Pancreatitis (inflammation of the pancreas)
• Gallbladder disorders (e.g., gallstones)
• Changes in kidney function due to dehydration
• Hypersensitivity reactions such as rash
• Angioedema (sudden swelling of skin or mucous membranes)
• Anaphylactic reaction (severe allergic reaction)
• Worsening of diabetic retinopathy with rapid blood sugar improvement

Serious Side Effects – Contact Your Doctor Immediately

• Persistent severe abdominal pain with or without vomiting (possible pancreatitis)
• Severe or prolonged nausea, vomiting, or diarrhea (risk of dehydration or kidney damage)
• Swelling of face, lips, tongue, or throat (possible allergic reaction)
• Pain in the upper right abdomen or jaundice (possible gallbladder or liver issue)
• Sudden vision deterioration (diabetic retinopathy)

Sources:
SmPC § 4.8 (EMA 2023);
Mounjaro Package Leaflet (NL 2023).

Mounjaro must not be used in the following situations:

• If you are allergic to tirzepatide or any of the other ingredients of this medicine (such as sodium chloride, sodium phosphate, or water for injection);
• If you have severe stomach or intestinal problems leading to delayed gastric emptying, such as gastroparesis;
• If you have severe liver or kidney problems, as there is insufficient experience with safe use;
• In children and adolescents under 18 years (safety and efficacy have not been established).

Additionally, Mounjaro should be used with caution alongside insulin or other blood sugar-lowering agents, as this may increase the risk of low blood sugar (hypoglycemia).

Sources:
SmPC §4.3 and §4.4 (EMA 2023);
Mounjaro Package Leaflet (NL 2023).

Mounjaro must not be used during pregnancy. There are no data on its use in pregnant women. Animal studies have shown harm to the unborn animal at high doses. Women planning to become pregnant should stop using Mounjaro at least one month before pregnancy, as the medicine remains active in the body for a long time.

It is unknown whether tirzepatide (the active substance) passes into breast milk. Therefore, the use of Mounjaro during breastfeeding is not recommended.

There is no evidence that Mounjaro affects fertility in humans.

Source: SmPC §4.6 (EMA 2023).