Key takeaways:
Mounjaro (tirzepatide) is a once-weekly injection used to treat Type 2 diabetes in adults. You can inject it beneath the skin of the stomach, thigh, or upper arm.
Mounjaro comes as a single-dose pen and vial, as well as a multi-dose vial and pen (Mounjaro KwikPen). Each form has unique injection instructions that you should review before using it.
Which injection site you choose doesn’t greatly affect how much Mounjaro your body absorbs. Just make sure to rotate the spot where you inject it if you’re using the same area of the body each week.
There are ways to save on Mounjaro. If you’re eligible, a manufacturer savings card could help you get Mounjaro for as little as $25 per prescription.
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Mounjaro (tirzepatide) is a popular medication for adults living with Type 2 diabetes. It’s available as a once-weekly injection that you can give to yourself at home.
But where should you inject Mounjaro? And how do you know if you’ve done it properly? It’s common to ask these questions whether you’re new to the medication or have been on it for a while. Below, we review how to inject Mounjaro (including Mounjaro KwikPens), plus other tips to set you up for success.
How to inject Mounjaro single-dose pens properly
You can inject Mounjaro in the stomach or thigh. If another person is administering your dose for you, they can also inject it in the back of your upper arm. Once you’ve decided on your injection site, there are five main steps to follow to properly use Mounjaro pens.
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1. Gather your supplies
Make sure you have everything needed to give yourself your injection. This includes:
A new Mounjaro pen
Alcohol swabs
Gauze pads
A needle disposal container
Mounjaro pens are best stored in the refrigerator (between 36°F and 46°F). You can take the pen you’ll be using out of the fridge about 30 minutes before your dose. This can help make the injection more comfortable.
Check your Mounjaro pen before you get started. Make sure the medication in the pen is clear, the expiration date hasn’t passed, and the pen isn’t damaged.
Mounjaro pens are single-use only and come with a needle already attached. So don’t remove the gray safety cover until you’re ready to inject your dose.
2. Clean the injection site
Before cleaning your desired injection site, wash and dry your hands. This helps prevent infection. If soap and water are unavailable, alcohol-based hand sanitizer is a good alternative.
Once your hands are dry, use an alcohol swab to clean the injection area. Allow it to fully air dry. Don’t blow on the area to help dry the alcohol. Blowing on it can contaminate the area with germs that live naturally in your mouth.
3. Remove the gray safety cover
Before removing the gray safety cover from the Mounjaro pen, make sure the pen is in the locked position. That way you won’t accidentally lose any of the medication. You can check this by looking for a closed padlock symbol on the pen by the purple injection button.
Once you’ve confirmed your pen is in the locked position, carefully remove the gray safety cover. Place the pen directly on the desired injection area. Turn the lock ring to unlock the pen (open padlock symbol). Don’t replace the gray safety cover once removed as you may damage the needle on the pen.
4. Inject your dose
Press and hold the purple injection button for at least 10 seconds. You should hear two clicks during this step. The first click happens when the injection starts. The second click happens when the injection finishes. You’ll know your injection is complete if you see a gray plunger in the medication window.
Once the injection is finished, remove the pen from your body. Be careful not to touch the needle with your fingers. It’s common to see a little blood near the injection site. Use a gauze pad to gently dab (not rub) the area. Rubbing the area could irritate the injection site.
5. Dispose of your pen
After your dose has been administered, your Mounjaro pen will be empty. You can safely throw it away in a needle disposal container. An FDA-cleared sharps container is ideal. If you don’t have a sharps container, a sturdy plastic container with a tight-fitting lid, such as a laundry detergent bottle, would be acceptable to use instead.
How to inject Mounjaro KwikPens properly
Mounjaro KwikPens contain four doses of medication in each pen. The multi-dose KwikPen device has different instructions for using it. But you can still use the same injection sites: stomach, thigh, or upper arm.
One key difference is that Mounjaro KwikPens don’t come with a needle already attached. And there are no pen needles provided inside the package. So you’ll need to purchase pen needles separately. You can ask your prescriber or pharmacist about purchasing pen needles.
Don’t share your Mounjaro KwikPen with anyone, even if you use a different pen needle. Sharing Mounjaro KwikPens can lead to infection.
The steps below explain how to use a Mounjaro KwikPen.
1. Gather your supplies
Gather the following supplies:
The Mounjaro KwikPen you’ll be using
A pen needle
Alcohol swabs
A gauze pad
A bandage
A sharps container or suitable alternative
2. Clean the injection site
Just like with Mounjaro single-use pens, you should clean your injection site with an alcohol swab. Let the area air dry. Don’t blow on your skin to try to dry it off faster.
3. Remove the gray pen cap
Pull the gray cap straight off your Mounjaro KwikPen. Check the medication cartridge. The liquid inside should be clear and colorless to slightly yellow. And be sure to check the expiration date on the pen.
Wipe the red inner seal at the end of the pen with an alcohol swab. Use a different swab than the one you used to clean your skin.
4. Attach a pen needle
Remove the paper tab from your pen needle. Push the capped pen needle onto your Mounjaro KwikPen. Twist the needle until it’s screwed on tightly.
Pull the outer needle cover off, but don’t throw it away. Place it aside for later. Then, carefully remove the inner needle shield and throw it away in your normal trash.
Make sure you always use a new pen needle for every injection. Reusing needles raises your risk of infection and injection site reactions.
5. Prime your pen (if it’s new)
If your Mounjaro KwikPen is new, you’ll need to prime it before your first injection. This will help remove extra air from the cartridge, so that you get your full dose.
To prime a Mounjaro KwikPen, turn the dose knob until you hear two clicks. There should also be an extended line in the dose window.
Hold your pen with the needle pointing up. Gently tap the cartridge with your finger to help air bubbles rise.
Push the purple injection button in until it stops. Continue holding the button in, and slowly count to 5. There should be a “0” in the dose window. A drop of liquid should come out of the needle. This means your pen is primed.
If you don’t see a drop of liquid, repeat this step up to two more times. If you still don’t see a drop, change your pen needle and repeat this step one more time. If you still don’t see a drop, don’t use the pen. Contact your pharmacy or call the manufacturer at 1-800-545-5979.
6. Dial up your dose
Turn the dose knob all the way until it stops. There should be a “1” in the dose window. This is your full weekly dose.
Don’t count clicks as you turn the knob. And don’t try to inject a partial dose.
7. Inject your dose
Insert the needle into your skin at a 90-degree angle. You don’t need to pinch your skin while giving yourself a dose. Push on the purple injector button with your thumb. Keep pushing the button until it stops. Hold the button down and slowly count to 5. If there’s a “0” in the dose window, it means your dose is complete.
Remove the needle from your skin. It’s normal for there to be a drop of liquid at the end of the needle. It’s also normal to see a drop of blood at your injection site. Gently dab (not rub) the injection site with a gauze pad. You can apply a bandage to the area if needed.
If you remove the needle from your skin and don’t see a “0” in the dose window, don’t worry. Just reinsert the needle in the same injection site and finish injecting your dose. Don’t redial the dose.
8. Dispose of your pen needle
Carefully replace the outer needle cap that you set aside in step 4. Then, unscrew the pen needle and place it in a sharps container (or suitable alternative). Place the gray pen cap back onto your Mounjaro KwikPen.
Don’t store your pen with a pen needle attached to it. This can allow medication to leak out of the pen. It can also cause air and germs to enter the medication cartridge.
If you’ve used the last dose in your Mounjaro KwikPen (or the pen has been opened for more than 30 days), it’s time to discard it. You can throw the KwikPen (without the needle) in your regular trash. You can also dispose of it in your sharps container, if you’d prefer.
How does using Mounjaro vials differ from using Mounjaro pens?
Mounjaro single-dose and multi-dose vials are available in the same doses as the pens. But if you’re using the vials, you’ll need syringes as well. Discuss with your prescriber or pharmacist which size syringe and needles would be best for you.
Similar to Mounjaro pens, you should gather your supplies and clean your injection site first. But after those steps, using the vials are a little different from using the Mounjaro pens.
1. Prepare the vial
Remove the protective cap from the top of the vial. Wipe the rubber stopper with an alcohol swab. To avoid contamination, don’t use the same alcohol swab that you used to clean your skin. Place the vial on a flat sturdy surface to prepare for the next step.
2. Prepare the syringe
Carefully remove the needle shield from your syringe. Hold the syringe with the needle pointing up, and use one hand to pull the plunger down until the plunger tip is at 0.5 mL for single-dose vials and 0.6 mL for multi-dose vials.
Turn the syringe over and push the needle straight down into the vial’s rubber stopper. Push the 0.5 mL or 0.6 mL of air into the vial. This makes it easier to draw the medication out of the vial.
3. Prepare the dose
Once you’ve pushed the air into the vial, carefully turn the vial and syringe upside down. Use one hand to hold the Mounjaro vial. With your other hand, slowly pull the plunger of the syringe down until the plunger tip is just past the syringe’s 0.5 mL or 0.6 mL line.
Gently tap the syringe to help any air bubbles rise to the top. Slowly push the plunger until the tip is at the 0.5 mL or 0.6 mL line. Turn the vial and syringe back over, and remove the syringe from the vial.
4. Inject your dose
Insert the needle into your chosen injection site, and push the plunger down to inject the dose. Leave the needle in your skin for at least 5 seconds to help you get your full dose.
5. Dispose of your syringe and vial
After 5 seconds have passed, pull the needle out of your skin and throw it away in a sharps container. Do not recap your needle. Doing this can cause you to injure yourself. Empty vials can be thrown away in your regular trash.
You should use a new needle for each dose. Using a fresh needle reduces your chances of infection and irritation of the injection site.
If you’re using a multi-dose vial and it still has doses left in it, place the vial back into the box it came in. You can store the box and vial in the fridge (between 36℉ and 46℉) or at room temperature (up to 86℉). Discard the vial after you’ve used 4 doses or it’s been opened for more than 30 days, whichever comes first.
Where can you inject Mounjaro?
You can inject Mounjaro subcutaneously (under the skin) in one of three areas of your body:
Stomach: Aim for at least 2 inches away from your belly button. Avoid using your waistline and the area around your hip bones.
Thigh: Aim for the outer thigh area. You shouldn’t inject Mounjaro on the inner thigh.
Back of the upper arm: Aim for 3 inches below shoulder or above elbow. Most people can’t reach this area when self-injecting Mounjaro. But it can be an option if another person is administering your doses for you.
Be sure to change your injection site with each dose. You can use the same area of the body, but pick a different spot for each dose. For instance, if you inject Mounjaro on the right side of your stomach one week, the next week you should use the left side. Rotating your injection sites increases your chances of getting the full dose, and decreases your risk of injection site reactions.
Does where you inject Mounjaro make a difference?
No, it doesn’t matter where you inject Mounjaro as long as you choose one of the three areas discussed above: your stomach, outer thigh, or back of the upper arm.
Clinical studies haven’t found a significant difference in how well Mounjaro is absorbed based on the injection site. All three injection sites appear to have similar levels of absorption. So the best place to inject Mounjaro is wherever you’re most comfortable.
What if you inject Mounjaro in the wrong spot?
If you inject Mounjaro into the wrong spot, contact your prescriber. Depending on where you injected it, you may need to adjust the timing of your next dose. Don’t inject a second dose to make up for the one administered incorrectly, unless your prescriber tells you to do so.
If your prescriber is unavailable, you can also contact your pharmacist or call the manufacturer at 1-800-545-5979.
When is the best time to inject Mounjaro?
The best time to inject Mounjaro is when you’re most likely to remember it. You can inject it at any time of day that works for you. Just make sure you’re injecting doses on the same day each week. This helps the medication to work consistently.
What if you miss a dose of Mounjaro?
If it’s been less than 4 days since you missed a dose of Mounjaro, inject it as soon as you remember. Return to your usual injection schedule with your next dose. But if 4 days or more have passed, skip the missed dose and inject the next one at its usual time. Don’t use two doses of Mounjaro within 3 days of each other.
For instance, if you usually inject on Saturday and remember on or before Tuesday, inject your dose as soon as you can. Then inject your next dose on Saturday like usual. But if you remember on Wednesday or later, skip the missed dose. Resume your usual injection schedule on Saturday.
Tips to make sure you receive your full Mounjaro dose
After you’ve injected Mounjaro, it’s common to wonder if you’ve injected it correctly.
The following tips can help you to receive your full dose of Mounjaro every time:
Don’t remove the gray KwikPen cap or set your Mounjaro single-dose pens to the unlocked setting until you’re ready to use it.
Make sure your Mounjaro pen or vial isn’t damaged or expired.
Rotate injection sites with every dose to prevent irritation.
Inject Mounjaro into healthy skin. Don’t use cut, swollen, or scarred skin.
Don’t use the same injection site with other injectable medications, such as insulin.
If you’re using Mounjaro KwikPens, use a new pen needle with each dose.
If you’re using Mounjaro vials, use a new syringe with each dose.
Don’t store Mounjaro KwikPens with a pen needle still attached.
Keep the needle of your injector pen or syringe in your skin for as long as directed after injecting the dose. Remember, it’s at least 10 seconds for Mounjaro single-dose pens and at least 5 seconds if you’re using Mounjaro KwikPens or the vials and separate syringes.
How to save on Mounjaro
There are ways to save on Mounjaro, which is available as a brand-name medication. If you have commercial insurance, you may be eligible to pay as little as $25 per prescription through the manufacturer’s copay savings program.
Frequently asked questions
The length of Mounjaro’s needles isn’t listed on the single-use pen’s labeling. But generally, needles used for subcutaneous injections are very short — between 4 mm and 12 mm (0.15 inches to 0.5 inches). They’re also fairly thin, with needle gauges typically ranging from 29G to 32G.
Mounjaro KwikPens are compatible with most brands of pen needles, such as BD. The following needle lengths can be used: 4 mm, 5 mm, 6 mm, 8 mm, and 12.7 mm. And the KwikPens can be used with the following pen needle gauges: 29G, 30G, 31G, 32G, 33G, and 34G.
If you inject Mounjaro into a stretch mark, your body may not absorb the medication properly. The skin may also be harder for a needle to penetrate. It’s best to inject Mounjaro into skin that’s free of cuts, bruises, and scars (including stretch marks).
Everyone’s experience with injections is different. For many people, they feel little to no pain when giving themselves under-the-skin injections, such as Mounjaro. It’s common for people to find the stomach to be the most comfortable injection site to use.
The length of Mounjaro’s needles isn’t listed on the single-use pen’s labeling. But generally, needles used for subcutaneous injections are very short — between 4 mm and 12 mm (0.15 inches to 0.5 inches). They’re also fairly thin, with needle gauges typically ranging from 29G to 32G.
Mounjaro KwikPens are compatible with most brands of pen needles, such as BD. The following needle lengths can be used: 4 mm, 5 mm, 6 mm, 8 mm, and 12.7 mm. And the KwikPens can be used with the following pen needle gauges: 29G, 30G, 31G, 32G, 33G, and 34G.
If you inject Mounjaro into a stretch mark, your body may not absorb the medication properly. The skin may also be harder for a needle to penetrate. It’s best to inject Mounjaro into skin that’s free of cuts, bruises, and scars (including stretch marks).
Everyone’s experience with injections is different. For many people, they feel little to no pain when giving themselves under-the-skin injections, such as Mounjaro. It’s common for people to find the stomach to be the most comfortable injection site to use.
The bottom line
Knowing how to inject Mounjaro (tirzepatide) helps you get the most benefit from your medication. Mounjaro comes as a single-dose pen and vial, as well as a multi-dose vial and pen (Mounjaro KwikPen). The instructions for injecting your dose varies, depending on which form you’re using.
There’s no best place to inject Mounjaro. Just make sure you’re injecting the medication into the skin of your stomach, thigh, or upper arm. Your body absorbs similar amounts of Mounjaro regardless of where you inject it. Talk to your prescriber or pharmacist if you have questions about how to inject Mounjaro.
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References
Centers for Disease Control and Prevention. (2024). About handwashing.
Eli Lilly Canada. (2026). Are pen needles included with Zepbound KwikPen? What pen needles are appropriate to use?
Eli Lilly and Company. (2024). Instructions for use: Mounjaro (tirzepatide).
Eli Lilly and Company. (2026). Mounjaro- tirzepatide injection, solution [package insert].
MedlinePlus. (2025). Subcutaneous (SQ) injections.
MedlinePlus. (2026). Tirzepatide injection.
Memorial Sloan Kettering Cancer Center. (2023). How to give yourself a subcutaneous injection using a prefilled syringe.
Schneck, K., et al. (2024). Population pharmacokinetics of the GIP/GLP receptor agonist tirzepatide. CPT: Pharmacometrics & Systems Pharmacology.
University of Texas at Austin. (n.d.). Sharps safety.
