What is the proper technique for injecting Mounjaro (tirzepatide) in a patient with type 2 diabetes?

How to Inject Mounjaro (Tirzepatide)

Mounjaro should be injected subcutaneously into the abdomen, thigh, or upper arm using proper technique to ensure optimal absorption and minimize complications.

Injection Site Selection

The abdomen is the preferred injection site due to fastest absorption rate, followed by arms, thighs, and buttocks. 1

• Inject into subcutaneous tissue of the abdomen (avoiding a 2-inch radius around the navel), anterior and lateral aspects of the thigh, or upper arm 1
• Truncal sites (abdomen) are preferable to limb sites, especially in leaner patients, as they have thicker subcutaneous tissue and reduce risk of inadvertent intramuscular injection 1, 2
• Avoid injecting into areas with lipohypertrophy, scars, or damaged tissue, as absorption will be unpredictable 1, 2

Proper Injection Technique

Use short needles (4-mm pen needles) and inject at a 90-degree angle for most patients to ensure subcutaneous delivery and avoid intramuscular injection. 1

• Most individuals can lightly grasp a fold of skin, release the pinch, then inject at a 90° angle 1
• Thin individuals or children should use short needles or inject at a 45° angle to avoid intramuscular injection, especially in the thigh 1
• Keep the needle embedded within the skin for 5 seconds after complete delivery of the dose 1
• Routine aspiration (drawing back to check for blood) is not necessary 1

Site Rotation Protocol

Rotate injection sites systematically within one area (e.g., different spots within the abdomen) rather than rotating to different body areas with each injection. 1

• Systematic rotation within one area decreases day-to-day variability in absorption 1
• Regular site rotation is essential to prevent lipohypertrophy, which appears as soft, smooth raised areas that cause erratic absorption and unpredictable glucose effects 1
• Patients should inspect injection sites for redness, swelling, or lipohypertrophy before each injection 1

Pre-Injection Preparation

• Ensure hands and injection site are clean before injection 1
• Mounjaro comes as single-dose prefilled pens and does not require mixing or resuspension like some insulin formulations 3
• The injection site should be visually inspected and palpated for any abnormalities before proceeding 1

Special Considerations for Mounjaro

Mounjaro follows the same injection technique principles as insulin and other GLP-1 receptor agonists, with the same risk mitigation strategies for lipohypertrophy. 1

• The risk of lipohypertrophy is considerably less with GLP-1/GIP agonists like Mounjaro compared with insulin, though subcutaneous nodules have been reported with similar medications 1
• Mounjaro can be administered on the same day as basal insulin without drug-drug interactions if combination therapy is prescribed 4
• Adverse events are primarily gastrointestinal (nausea, diarrhea, vomiting) and are generally mild to moderate in severity 3, 5

Common Pitfalls to Avoid

• Never inject into areas of lipohypertrophy, as this causes erratic absorption and increases risk of hypoglycemia and hyperglycemia 1
• Avoid intramuscular injection, which causes unpredictable absorption and variable glucose effects 1
• Do not reuse needles excessively, as needle tips can become bent or hooked, potentially lacerating tissue 1
• Avoid injecting cold medication directly from refrigerator, as this may contribute to lipohypertrophy development 1