Quick Answer: Mounjaro pens come with an expiration date labelled on the pen itself. However, unrefrigeration for over 30 days, exposure to heat, as well as other storage and environmental factors can cause your medicine to expire prematurely.
Mounjaro (tirzepatide) is a popular medication in the UK for both type 2 diabetes and weight loss. If you're using Mounjaro, you may be wondering: Does it expire? Can you still use it after the expiration date? And what happens if you inject expired Mounjaro?
In this guide, we'll answer all these questions and help you understand how to store your medication properly to ensure it remains effective. We'll also cover the risks of using expired Mounjaro and best practices for storage and disposal.
Related article: How to Store Mounjaro and Does it Really Need to be Refrigerated?
Understanding Mounjaro's Expiration Date
Knowing how long Mounjaro is good for and where to find its expiration date is essential for ensuring you get the full benefits of your medication. Let's explore the key details about Mounjaro's shelf life and how to determine if your injection pens aren't out of date.
What is the expiration date of Mounjaro?
Every Mounjaro pen comes with an expiration date printed on the packaging and the pen itself. This date indicates how long the manufacturer guarantees the medication's full effectiveness and safety if correctly stored in the refrigerator and before opening.
Once past this date, the manufacturer cannot guarantee that the medication will work as intended. The injection pen is therefore considered expired and should not be used.
You'll find the expiration date on the pen itself and on the box it came in. Always check this before using Mounjaro, especially if you've had it for a while. It's a good idea to make a habit of checking the expiration date whenever you collect a new prescription to ensure you're using the freshest supply available in your fridge.
How long is Mounjaro good for?
Typically, Mounjaro has a shelf life of around 2 years from the date of manufacture. But always double check on the pen itself, as it depends on your pharmacy's stocks!
The printed expiration date assumes the injection pen has been stored correctly (more on that below). Even if the pen appears fine after, it may no longer be as effective, which could impact your treatment.
Related article: How to Travel With Mounjaro: Tips for Cold Storage, Flying and Travelling Abroad!
Can You Use Mounjaro After the Expiration Date?
As your Mounjaro pen nears or passes its expiration date, you may be wondering whether it's still safe and effective to use.
Technically, you could, but it's not recommended. Expired tirzepatide might have reduced potency, and in some cases, it could even cause unexpected side effects. Even if the pen looks fine, there's no way to tell how much of the active ingredient has degraded.
What happens if you use expired Mounjaro?
The biggest concern with using expired Mounjaro is that it may not work as effectively. Over time, the active ingredient (tirzepatide) can break down, meaning your body may not receive the full dose it needs.This can lead to uncontrolled blood sugar levels for diabetics or reduced weight loss benefits for people using Mounjaro on their weight-loss journey.
Is using expired Mounjaro dangerous?
While expired Mounjaro isn't likely to be dangerous, the biggest risk is that it won't be as effective.
Injecting expired Mounjaro could lead to uncontrolled blood sugar levels in diabetics or reduced weight loss effects. If the medication doesn't work as expected, it could cause fluctuations in glucose levels, leading to prolonged hyperglycaemia and symptoms like fatigue, excessive thirst, or dizziness.
In some cases, especially if the pen has been refrigerated for too long, there may be an increased risk of contamination or breakdown of the formula. This could introduce harmful bacteria, increasing the likelihood of infections or adverse reactions.
Additionally, using ineffective medication may result in delayed treatment progress, requiring adjustments to dosage or switching to a new prescription sooner than anticipated.
Can expire Mounjaro Make Your Sick?
Expired Mounjaro is unlikely to cause immediate illness, but there are some potential risks. If the medication has been compromised due to improper storage, bacterial contamination could occur, leading to infections or localised irritation at the injection site.
Additionally, if the drug is no longer effective, poorly managed blood sugar levels in diabetics could result in hyperglycaemia, leading to symptoms such as nausea, vomiting, or confusion. If you feel unwell after using expired Mounjaro, seek medical advice promptly.
Related article: What if Mounjaro is Delivered or Gets Warm?
How to Tell if Your Mounjaro Pen Has Expired
The first thing is naturally to check the expiration date labelled on the pen itself. If it's past that date, do not use the pen, even if the medicine inside looks fine.
But Mounjaro may expire prematurely, before its printed expiration date, especially in the following situations:
- The pen has been unrefrigerated for more than 30 days.
- The pen has been exposed to warm temperatures above 30°C.
- The pen has been accidentally frozen.
There are some visual signs that may help indicate that Mounjaro has gone bad or expired prematurely, including:
- Changes in colour or texture - If the solution looks cloudy, discoloured, or has particles floating in it, don't use it.
- Leaks or damage to the pen - A damaged pen could indicate that the medication inside is no longer stable.
However, expired tirzepatide ins't always visible to the naked eye! So, if you have doubt about whether your Mounjaro pen is still safe for use or not, ask for your doctor or pharmacist's advice before using it.
What to do if you accidentally inject expired Mounjaro?
If you've already used an expired dose of Mounjaro without knowing it, don't panic. It's unlikely to cause harm, but you may want to monitor your blood sugar levels (if you're using Mounjaro for diabetes) and contact your healthcare provider if you notice anything unusual.
Do not inject a new dose without your doctor's advice. There's no way to know how effective the expired dose was. It may have worked, it may have not, or it may have but just a little… Injecting double dose of tirzepatide can be dangerous. If you suspect reduced effectiveness, ask for your doctor's advice and consider switching to a fresh pen for your next injection.
Proper Storage to Maintain Mounjaro's Effectiveness
Ensuring that your Mounjaro pens are stored correctly is crucial for maintaining their effectiveness and extending their shelf life. Proper storage prevents tirzepatide from degrading too soon, ensuring you get the full benefit from each dose in all safety. Let's go over the best practices for keeping your Mounjaro pens safe and effective the longest possible:
- Always store Mounjaro in the fridge (between 2°C and 8°C) before you need to use it.
- Keep your injection pens in their original packaging to protect them from light and temperature fluctuations.
- Never freeze Mounjaro - frozen Mounjaro is no longer usable and must be discarded, even if it thaws afterwards. To prevent Mounjaro from accidentally freezing, do not store it near the freezer compartment of your fridge.
- If needed, Mounjaro pens can be kept at room temperature (below 30°C) for up to 30 days, but after this period, they must be used or discarded, even if their printed expiration date hasn't past yet.
- Always carry Mounjaro in a cooling case, especially when travelling our out for the day in the summer.
Can improper storage make Mounjaro expire faster?
Yes! Exposure to heat, light, or freezing temperatures can break down the medication, making it expire sooner than the printed date. Storing your pens properly will help maintain their effectiveness until the listed expiration date.
Additionally, any Mounjaro pen that's been out of the fridge for longer than 30 days is considered expired, independently of its printed expiration date.
When and where to dispose of your Mounjaro pen
Dispose of your Mounjaro pen if:
- It has passed the expiration date.
- It has been stored incorrectly (exposed to extreme heat or frozen).
- The solution inside looks cloudy or discoloured.
Unfortunately, Eli Lilly, the manufacturer of Mounjaro KwikPens do no have a recylcing program (yet!). Meanwhile, you can throw your empty or expired pens in a sharps container or in your household trash (after removing the needle). The needle itself must always be disposed of in sharps containers.
Related article: Can You Use Expired Insulin or Will it Make You Sick? How to Dispose of it?
Can Mounjaro cause allergic reactions?
Yes, some people may experience allergic reactions to Mounjaro, such as skin rashes, itching, or swelling. If you notice severe symptoms like difficulty breathing or swelling of the face or throat, seek medical help immediately.
Final Thoughts
While it might be tempting to use expired Mounjaro to avoid waste, it's not worth the risk. The medication may not be as effective, which could impact your treatment. Always check the expiration date, store it correctly, and when in doubt, ask your pharmacist or doctor. Keeping your medication fresh and potent is key to ensuring it works as intended.
We'd Love to Hear Your Thoughts!
Got more questions about Mounjaro, its storage conditions and expiration dates? Drop them in the comments, and we'll be happy to help!
