How to use the Mounjaro (tirzepatide) hidden-needle pen: inspect, place flat on the skin, unlock, and press until the second click. Not medical advice.
Pre-injection checklist
- ✓Check the label: right medication, right dose, not expired.
- ✓Inspect the solution through the window. It must be clear and colorless to slightly yellow. Do not use a pen with cloudy or discolored liquid or with particles.
- ✓Wash your hands with soap and water.
- ✓Let a refrigerated pen reach room temperature for a short while before use, a cold dose stings more.
Step-by-step guide
- 1
Inspect and unlock the pen
Take the pen out of the carton, check the label and the solution in the window, and only just before injecting pull off the gray base cap. Turn the lock ring to the unlocked position as the Eli Lilly Instructions for Use describe.
Pro tipAlways check the fluid is clear and colourless before injection. - 2
Choose and clean a site
Pick the abdomen or front of the thigh (upper arm caregiver-only), rotating from last week, wipe with an alcohol pad, and let it air-dry.
Pro tipAlways check the fluid is clear and colourless before injection. - 3
Place the pen flat on the skin
Set the clear end flat and firmly against the cleaned skin. The needle is hidden and only triggers when you press.
Pro tipAlways check the fluid is clear and colourless before injection. - 4
Press and hold until the second click
Press the purple injection button. You will hear a first click as it starts. Keep holding the pen firmly against the skin until a second click sounds and the gray plunger fills the window to show it is finished, usually about 10 seconds.
Pro tipAlways check the fluid is clear and colourless before injection. - 5
Lift away and dispose
Lift the pen straight off the skin. The needle retracts. Press gauze gently if there is bleeding, do not rub, and drop the whole pen straight into an FDA-cleared sharps container.
Pro tipAlways check the fluid is clear and colourless before injection.
After the injection
- Record the site used so the next dose moves to a different area.
- Store unopened pens refrigerated per the Instructions for Use.
Common mistakes
- Difficulty breathing, swelling of the face, throat, or tongue, or hives, signs of a serious allergic reaction, call emergency services.
- Severe, persistent abdominal pain, pancreatitis is listed in the Mounjaro Important Safety Information.
- A site that becomes progressively red, warm, or swollen over 24 to 48 hours, possible infection.
Frequently asked questions
How do I use the Mounjaro pen step by step?+
Inspect the pen, unlock it and pull the cap, clean a rotated site, place the clear end flat on the skin, press the button and hold until the second click (about 10 seconds), then lift straight off and dispose of the whole pen. The Eli Lilly Instructions for Use describe each step. See also how to inject Mounjaro and where to inject Mounjaro.
What do the two clicks on the Mounjaro pen mean?+
The first click means the injection has started. The second click, together with the gray plunger showing in the window, means the full dose has delivered. Keep the pen pressed firmly to the skin between the two clicks.
How long do I hold the Mounjaro pen against my skin?+
Hold the pen pressed until the second click sounds and the gray plunger fills the window, usually about 10 seconds. Check the exact direction in your pen's Instructions for Use.
Do I need a separate needle for the Mounjaro pen?+
No. The Mounjaro single-dose pen has a fixed, hidden needle that retracts after the injection. You only choose a separate pen needle if you dose from a vial with a syringe. See the pen needle size guide.
Sources
- Eli Lilly. Mounjaro (tirzepatide) Instructions for Use, single-dose pen.
- Eli Lilly. Mounjaro (tirzepatide) Prescribing Information.
- FDA. Drugs@FDA, Mounjaro labeling.
- Frid AH et al. 2016. New Insulin Delivery Recommendations. Mayo Clinic Proceedings 91(9):1231-1255.
- FDA. Best Way to Get Rid of Used Needles and Other Sharps.
