If you’re new to weight loss injections or have recently switched to Mounjaro, it’s important to understand how to administer your medication safely. In this blog post we’ll cover dosage and storage instructions and most importantly, where to inject Mounjaro. 

What is Mounjaro?

Mounjaro is a MHRA-approved weight loss injection that contains the active ingredient tirzepatide. Other popular weight loss medications – Wegovy and Saxenda belong to a class of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists. This means they mimic the GLP-1 hormone that is naturally released in the gastrointestinal tract when we eat. This then tells the body to produce more insulin, which controls blood sugar levels and regulates appetite by sending signals to tell the body it’s full. This helps prevent overeating. [1]

Mounjaro is slightly different as it is both a GLP-1 and glucose-dependent insulinotropic peptide (GIP) receptor agonist. Also known as a dual agonist or ‘twincretin’. [2] Alongside the glycemic controlling benefits of the GLP hormone, mimicking the GIP receptor helps enhance insulin sensitivity, reduce hunger signals in the brain to reduce appetite, and can improve fat metabolism. [3] In clinical studies, tirzepatide has shown to help people lose up to 20% of their body weight after a year. [4]

Description of Mounjaro injection

Mounjaro is taken as a once-weekly injection and is administered using an injection pen. Mounjaro KwikPen is a disposable multi-dose single-patient-use pre-filled pen. The pen contains 4 fixed doses, one dose taken weekly. When you receive your Mounjaro medication, The Patient Information Leaflet inside the box will provide detailed instructions on how to administer your injection – but you can also get in touch with your clinical team here at MedExpress if you have any questions or concerns.  

How to use Mounjaro

You’ll take your Mounjaro medication on the same day each week, at any time of the day. If that day is no longer convenient for you to administer your medication, it is possible to switch your day. Just make sure there are at least three days (72 hours) between your last dose and your next (new weekly) one. [6]

Dosage instructions

Mounjaro is a drug that requires titration. This is a way of gradually increasing the doses each month to help you get its maximum benefits with minimal side effects.  A typical Mounjaro dosing schedule would start at 2.5 mg for weeks 1-4 before reaching 15mg from Week 21 onwards. This is also known as your maintenance dose – the maximum amount you can have without experiencing adverse effects. [5] You won’t have to work out your doses yourself – your injection pens will come pre-filled with four doses. And your dose increases will be determined by your MedExpress clinical team on an ongoing basis – you can read more about Mounjaro dosage in our comprehensive guide here. 

Preparing the Mounjaro pen

Before administering your medication, you’ll need to get the injection pen ready. First, remove it from the refrigerator, leaving the cap on until you’re ready to inject. Next read the label to check the dose and expiration date. Then check the pen to make sure it’s not damaged and the solution is not frozen or cloudy. [6]

When you’re ready to inject, you’ll need to select a new needle and check it for damages, you’ll need to do this each time you administer your medication. If you see any damage, dispose of the needle in a sharps bin as this could affect sterility.

Then you need to push the needle onto the pen and twist until it’s secure and remove both caps, disposing of the inner cap and keeping the outer cap for later to safely dispose of your medication.

Priming the Mounjaro pen

Priming removes air from the cartridge and makes sure that your pen is working correctly. Your pen has been primed if a small amount of medicine comes out of the tip of the pen needle.

You can prime your pen by slowly turn the dose knob until you hear 2 clicks and the extended line is shown in the dose window. Then, with the needle pointing upwards, tap the cartridge holder gently to collect air bubbles at the top and release some medicine into the air by pushing the dose knob in until it stops, then slowly count to 5 while holding the dose knob. 

Choosing the Mounjaro injection site

Your medication must be delivered via subcutaneous injection – under the skin. You can choose to inject it in your stomach (abdomen) or thigh or upper arm, just remember to clean the area with the alcohol swab provided before you inject. [6] Each week, rotate your injection site to help prevent inflammation of the fat tissue, scarring or injection site reactions. [7] 

Administering the injection

To administer your medication, turn the dose knob until it stops and the ‘1’ icon is shown in the dose window.

Then, position the pen at your chosen injection site and insert the needle into your skin by holding down the dose knob while you count to 5. Once the ‘0’ icon is visible in the dose window you can remove the needle from your skin. 

What to do with your injection afterwards

Injections – and injection pens – must be disposed of safely. We’ll send you a sharps container with your first Mounjaro order to put your used injection pens in. Make sure you keep your container out of the reach of children. When you’re ready to dispose of it, do not put any element in your household recycling. When your sharps bin is full you can take it to your local pharmacy to be disposed of, or it can be collected by your local council. 

What to do if a dose is missed

There might be a time when missing your usual injection day is unavoidable. If this happens, just take the missed dose as soon as possible within four days (96 hours). If it has been more than four days since the missed dose, skip that one entirely and take your next dose on the next regularly scheduled day. [6]

Find out what treatment is suitable for you on our website.

References

1.Solan M. Understanding new weight-loss drugs [Internet]. Harvard Health. 2023 [cited 2024 Jul 3]. Available from: https://www.health.harvard.edu/staying-healthy/understanding-new-weight-loss-drugs 

2. Dutta P, Kumar Y, Babu AT, Giri Ravindran S, Salam A, Rai B, et al. Tirzepatide: A Promising Drug for Type 2 Diabetes and Beyond. Cureus [Internet]. 2023 May 1;15(5):e38379. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10231274/

3. Nguyen TMD. Adiponectin: Role in Physiology and Pathophysiology. International Journal of Preventive Medicine [Internet]. 2020 Sep 3;11. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7554603 

4. Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine [Internet]. 2022 Jun 4;387(3). Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2206038

5. Mounjaro: Uses, Dosage, Side Effects & Warnings [Internet]. Drugs.com. Available from: https://www.drugs.com/mounjaro.html 

6. How to Use, Dosing & Side Effects | Mounjaro® (tirzepatide) [Internet]. mounjaro.lilly.com. Available from: https://mounjaro.lilly.com/how-to-use-mounjaro#how-to-use 

7. Hirsch LJ, Strauss KW. The Injection Technique Factor: What You Don’t Know or Teach Can Make a Difference. Clinical Diabetes : A Publication of the American Diabetes Association [Internet]. 2019 Jul 1;37(3):227–33. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6640874/