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Tirzepatide is injected under the skin once a week, not into a vein or muscle. Approved tirzepatide products, including Mounjaro and Zepbound, can be injected into the abdomen or thigh. Another person can inject into the back of the upper arm. Rotate the injection site each week.

The steps depend on whether you use a single-dose pen, KwikPen, or vial. Follow the instructions for your specific device and prescribed dose.

Tirzepatide Injection at a Glance

Detail Instructions
Route Under the skin, or subcutaneously
Frequency 1 injection per week
Injection sites Abdomen, thigh, or the back of the upper arm when injected by another person
Food Can be injected with or without food
Site rotation Use a different spot within the same general area each week
Needle Use a new needle for every vial or KwikPen injection
Disposal Place used needles and syringes in a sharps container

Before Injecting Tirzepatide

  1. Confirm the medicine and dose. Check that the name, strength, and expiration date match your prescription.
  2. Inspect the solution. Do not use tirzepatide if it is frozen, cloudy, discolored, or contains particles. Approved tirzepatide should be clear and colorless to slightly yellow.
  3. Gather your supplies. Depending on the device, you may need the pen or vial, a new needle and syringe, an alcohol swab, gauze, and a sharps container.
  4. Wash your hands with soap and water.
  5. Choose a healthy injection site. Do not inject into skin that is bruised, tender, hard, scarred, thickened, lumpy, scaly, or damaged. Do not use the exact site used for another medicine.

How to Inject a Single-Dose Tirzepatide Pen

Mounjaro and some Zepbound pens are single-dose, prefilled pens. You do not draw the medicine into a syringe.

  1. Remove the pen from the refrigerator. Check the label, expiration date, and solution.
  2. Choose an injection site on the abdomen or thigh. Another person should inject into the back of the upper arm.
  3. Remove the protective base cap when you are ready to inject.
  4. Place the clear base flat against your skin.
  5. Unlock the pen according to the device instructions.
  6. Press and hold the injection button. Keep the pen against your skin until the injection is complete and the second click occurs, as directed in the product instructions.
  7. Remove the pen and place the entire used pen in an appropriate sharps container. Do not reuse or share it.

Single-dose pens can differ by product. Follow the printed Instructions for Use supplied with your Mounjaro or Zepbound pen.

How to Inject a Tirzepatide KwikPen

A KwikPen contains four fixed weekly doses and requires a compatible disposable pen needle.

  1. Remove the pen cap and check the label and medication.
  2. Wipe the red inner seal with an alcohol swab.
  3. Attach a new pen needle.
  4. Remove the inner needle shield. Keep the outer shield for later.
  5. Prime the KwikPen before each weekly injection according to the Instructions for Use. Priming releases a small drop of medication into the air.
  6. Choose an injection site on the abdomen or thigh. If you use the abdomen, stay at least 2 inches from the belly button.
  7. Turn the dose knob all the way until the full-dose symbol appears. Do not count clicks to measure the dose.
  8. Insert the needle into the skin.
  9. Press the dose knob fully and hold it while slowly counting to five.
  10. Remove the needle. A small drop of medication on the needle tip can be normal.
  11. If blood appears, gently press the site with gauze. Do not rub.
  12. Replace the outer needle shield, unscrew the needle, and place it in a sharps container.
  13. Replace the pen cap. Do not store the KwikPen with a needle attached.
  14. Discard the KwikPen after four doses, including any medication left inside. Do not transfer leftover medication into a syringe.

How to Inject Tirzepatide From a Vial

Use only the syringe size and dose measurement provided by your prescriber or pharmacist.

  1. Remove the vial from the refrigerator.
  2. Check the vial label, expiration date, and medication appearance.
  3. Wash your hands.
  4. Remove the protective vial cap and wipe the rubber stopper with an alcohol swab.
  5. Use a new sterile syringe and needle.
  6. Draw up the dose exactly as instructed. For an approved single-dose vial, the official instructions involve injecting air into the vial, turning the vial upside down, drawing up the medication, removing air bubbles, and aligning the plunger with the prescribed dose line.
  7. Inject the medication under the skin of the abdomen or thigh. Another person may inject into the back of the upper arm.
  8. Keep the needle in the skin for at least five seconds after pressing the plunger.
  9. Remove the needle without recapping it. Place the syringe and needle directly into a sharps container.

Important Warning About Compounded Tirzepatide

Do not assume that a compounded tirzepatide vial uses the same concentration, volume, syringe markings, or expiration instructions as Mounjaro or Zepbound.

Never convert milligrams to "units" without confirmation from the prescribing clinician or dispensing pharmacist. FDA has reported dosing errors and adverse events involving compounded injectable GLP-1 medicines. Compounded drugs are not FDA-approved and are not reviewed by FDA for safety, effectiveness, or quality before marketing.

What Should You Do If You Miss a Weekly Dose?

For FDA-approved Zepbound and Mounjaro, take the missed dose within 4 days, or 96 hours, if possible. If more than four days have passed, skip the missed dose and take the next dose on your regular day. Do not take two doses within 72 hours of each other.

When Should You Contact a Healthcare Professional?

Contact your prescriber promptly if you have severe or persistent vomiting, diarrhea, dehydration, or significant abdominal pain. Seek emergency help for symptoms of a serious allergic reaction, including trouble breathing, facial or throat swelling, or widespread hives.

Tell healthcare professionals that you use tirzepatide before surgery or deep sedation. Tirzepatide can slow stomach emptying and may affect anesthesia planning.

Tirzepatide is contraindicated for people with a personal or family history of medullary thyroid carcinoma or Multiple Endocrine Neoplasia syndrome type 2.

If you are injecting tirzepatide for the first time, ask your prescriber, nurse, or pharmacist to demonstrate your device before you use it yourself.