If you are using weight loss injectables for the first time, knowing how to use your KwikPen can make the process feel much less intimidating. From taking the pen out of the fridge to choosing an injection site and completing the dose, each step matters
This step-by-step guide explains the basic process, including storage, preparation, injection sites and aftercare. Always follow the ‘Instructions for Use’ supplied with your pen and the technique demonstrated by your healthcare provider.
Key Takeaway
- Store your Mounjaro KwikPen correctly in the fridge before first use, and follow the product instructions for storage after opening.
- Prepare and prime the pen before every injection, following the manufacturer’s Instructions for Use.
- Use the recommended injection sites: the abdomen or thigh, or the back of the upper arm when administered by another person.
- Rotate injection sites weekly and avoid bruised, sore, scarred, or damaged skin.
- Follow your prescribed dose and schedule. Never increase your dose or inject more frequently without medical advice.
- Dispose of needles safely and seek professional guidance if unsure about injection technique, storage, dosage or persistent injection-site reactions.
What Are GLP-1 Weight Loss Injectables?
GLP-1 weight loss injectables are prescription medicines that act on hormones involved in appetite, digestion and blood sugar regulation. Mounjaro contains tirzepatide, which acts on both GIP and GLP-1 receptors. It is used alongside appropriate diet, lifestyle changes and physical activity as part of weight management.
Mounjaro is available in different strengths and may be supplied as a multi-dose KwikPen. The Mounjaro KwikPen is designed to deliver four weekly doses, and you should prepare and use the device according to the manufacturer’s Instructions for Use.
Because injection devices can work differently, the instructions in this guide apply specifically to the Mounjaro KwikPen.
How Should You Store Your Mounjaro KwikPen?
Unused Mounjaro KwikPen should be stored in the fridge at 2°C to 8°C. Do not freeze it.
After first use, you may store the KwikPen at room temperature up to 30°C for up to 30 days, according to the product instructions. Keep the pen protected from heat and light and follow the storage instructions supplied with your medicine.
Do not use the pen if it has been frozen, is damaged, expired, cloudy, discoloured or contains visible particles
What Should You Do Before Your Injection?
Before you inject your Mounjaro pen, wash your hands and prepare the items you need. Check the medication name, strength, prescribed dose and expiry date before use.
If you have been prescribed the KwikPen, your healthcare provider should show you the correct injection technique before your first dose and explain how to administer it.
The pen uses a new compatible needle for each injection. Needles may not be included with the pen, so check what has been supplied and ask your pharmacist or doctor if you are unsure which needle to use.
How Do You Prime the Mounjaro KwikPen?
Always follow the product instructions provided with your KwikPen when preparing and priming the pen. The Mounjaro KwikPen should be primed before every injection.
Your healthcare provider will explain how to prepare and prime your Mounjaro KwikPen before your first injection.
The priming process includes attaching a new needle, setting the pen to the prime position, holding the pen with the needle pointing upwards, and releasing a small amount of medicine into the air. Follow the manufacturer’s ‘Instructions for Use’ carefully each time you prepare the pen.
Where Are the Best Injection Sites?
The recommended injection site is under the skin of the stomach (abdomen) or thigh. Another person can administer the injection into the back of the upper arm.
When deciding where to inject:
- Abdomen: Choose an area of the stomach at least 5 cm from the belly button.
- Thigh: You can use the front or outer thigh.
- Upper arm: Have another person administer the injection into the back of the upper arm.
These areas contain subcutaneous fat, where the prescribed dose is intended to be administered.
Your healthcare provider can help you choose a suitable injection area based on the product instructions and your individual circumstances.
Should You Rotate Your Injection Site?
Yes. Rotate the injection site with each weekly injection rather than repeatedly using the same spot. You can continue using the same general area, but choose a different location within it.
For example, if you use your stomach in week 1, you can choose a different location on your thigh or another suitable site the following week.
Do not inject in the same area if the skin is sore, bruised, hardened, scarred or damaged.
Have Questions About Your Mounjaro KwikPen?
If you are unsure about your injection technique, dose or treatment, a GoMed doctor can provide personalised guidance through an online consultation.
How Do You Inject the Medication Under the Skin?
Once you have chosen your injection site and prepared the pen, administer the injection under the skin as directed in the Instructions for Use.
In general, the process involves:
- Choose and clean the injection site.
- Prepare the pen and attach a new needle.
- Prime the pen as instructed.
- Position the pen against the skin.
- Deliver the prescribed dose using the injection mechanism.
- Hold the pen in place for the required time to ensure the full dose is delivered.
- Remove the needle and dispose of it safely.
Your healthcare provider should demonstrate the technique before you administer your first injection. The exact steps can vary by pen version, so use the instructions supplied with your specific device.
What Should You Do After the Injection?
After completing the injection, remove the needle according to the Instructions for Use and dispose of it in an appropriate sharps container. Do not reuse needles.
Check the injection site to see whether there is any redness, itching or discomfort. A small amount of irritation may occur around the injection site.
If you experience persistent or worsening injection site reactions, speak with your healthcare provider.
Handle and store the pen according to the product instructions between doses.
The Mounjaro KwikPen contains four weekly doses. After the fourth dose, residual solution may remain in the pen, but do not use it as an additional dose. The pen should be discarded after the fourth dose or according to the manufacturer’s disposal instructions
What Injection Site Reactions Can Occur?
Injection-site reactions include redness, itching, minor discomfort, or pain and are usually mild and localised, although more significant reactions can occur.
To reduce irritation, change the injection site location every week and avoid injecting into irritated, bruised, or damaged skin. If the reaction becomes severe, spreads beyond the injection site or is accompanied by symptoms such as difficulty breathing or swelling of the face or throat, seek medical attention promptly.
What Is the Appropriate Dose for Weight Loss?
Mounjaro is taken once a week, and your healthcare provider determines the dose based on your response to and tolerance of the treatment. Do not inject it more frequently or in a larger amount than prescribed.
The usual starting dose of tirzepatide is 2.5mg once weekly for 4 weeks. This is an initiation dose, not a maintenance dose. The dose is generally increased to 5mg once weekly after 4 weeks, with further increases of 2.5mg after at least 4 weeks at the current dose when clinically appropriate. The maximum recommended adult dose is 15mg once weekly.
Your doctor will determine the appropriate dose based on your response and tolerance. Do not increase the dose yourself or inject more frequently than prescribed.
Do not change your dose yourself simply because your appetite suppression seems weaker or because you want faster weight loss.
What If You Are Unsure How to Use Your Mounjaro KwikPen?
If you are unsure about any part of the Mounjaro KwikPen process, do not guess. Ask your doctor or pharmacist to demonstrate the correct injection technique again.
An online doctor consultation may also help you discuss questions about your treatment. It is especially important to seek professional guidance if you are unsure about your dose, storage, injection technique or how to respond to side effects.
What Should First-Time Users Remember?
Using a Mounjaro KwikPen safely starts with understanding how to prepare, administer the correct dose and store your specific device. Always follow the product instructions and the technique your healthcare provider demonstrated, rather than relying on general guidance.
If you are unsure about how to use your Mounjaro KwikPen, speak with a healthcare professional before administering your next dose. GoMed offers doctor-led teleconsultations where you can discuss questions about your treatment, injection technique and other concerns with a licensed doctor.
References
- Health Sciences Authority, Singapore. New drug approvals – June 2025: Mounjaro KwikPen solution for injection in pre-filled pen. Singapore: HSA; 2025.
- Eli Lilly and Company. Mounjaro (tirzepatide) Prescribing Information. Revised 2026.
- Eli Lilly and Company. Mounjaro KwikPen: How to use and injection instructions. Eli Lilly; current manufacturer guidance.
- DKSH Singapore. Mounjaro Patient Information Booklet: Mounjaro KwikPen and needles – storage and disposal. Singapore; 2026.