What is the golden dose of Mounjaro & why you shouldn't use it

If you've finished the four injections in your Mounjaro KwikPen and can still see some liquid inside, you might wonder whether you're throwing away usable medicine. Online, this leftover liquid is often called the "golden dose" or "5th dose".

However, there is no official fifth dose of Mounjaro. Each KwikPen is designed to provide four fixed 0.6ml doses, with some additional solution needed for priming the pen (1). Any medicine left after your fourth dose should be discarded rather than injected.

Trying to extract it yourself could mean taking an incomplete or inaccurate dose and involves using the pen in a way it was not designed for (1,2).

In this article:

• What is the golden (5th) does of Mounjaro?

• How much is in the golden dose of Mounjaro?

• How do you get the golden dose of Mounjaro?

• Is the 5th dose of Mounjaro safe?

• Risks of using golden dose of Mounjaro

• Can you use the golden dose of Mounjaro?

What is the golden (5th) does of Mounjaro?

The "golden dose" is an unofficial name for the liquid that may remain inside a Mounjaro KwikPen after you have taken all four prescribed doses. It is leftover medicine, not an intended fifth dose.

Each KwikPen is designed to deliver 4 doses only. Each individual dose has a volume of 0.6ml. This volume remains the same regardless of which strength of Mounjaro you’re taking. What changes between strengths is the amount of Tirzepatide contained in that 0.6 mL.

You should discard the pen and any remaining solution once all your doses have been delivered, even if there is still liquid inside.

Why is there liquid left in my Mounjaro pen?

Mounjaro KwikPens contain some additional liquid because the pen needs to be primed before each injection to check that the pen and needle are working correctly (1,2). As a result, you may still see some medicine inside the pen after taking your fourth dose.

Newer Mounjaro KwikPens have been redesigned to leave less medicine behind after the fourth dose, so you may notice much less leftover liquid than with an older version of the pen (2). Both versions still provide the same four 0.6ml doses and are used in the same way.

Whichever version you have, any medicine remaining after your four doses is not an intended fifth dose and should be discarded with the pen.

How much is in the golden dose of Mounjaro?

There is no set number of mL in the Mounjaro "golden dose", and Eli Lilly’s new pens are designed to leave less medicine behind than the original KwikPen version.

Each Mounjaro KwikPen provides 2.4ml of medicine across four 0.6ml doses, plus some extra solution to allow it to be primed (1,2). But the exact amount left after your fourth dose depends on how much solution was used when priming it and which version of the pen you’re using.

How do you get the golden dose of Mounjaro?

Some people online describe forcing the pen mechanism or using a separate syringe to withdraw the remaining liquid and inject the golden dose.

Normally, Mounjaro KwikPens have a dialling mechanism to make sure you get exactly 0.6ml with every injection. After all four prescribed doses have been given, you cannot use it to dial another full dose, so accessing the remaining medicine means using the pen outside its intended instructions.

As neither method is approved by the manufacturer, we won’t provide instructions for extracting the golden dose and advise against these techniques.

Is the 5th dose of Mounjaro safe?

No, it is not safe to use the 5th or "golden" dose of Mounjaro. It is not one of the four measured doses the KwikPen is designed to provide, and the manufacturer specifically advises against using the pen after the four doses have been delivered. (3).

Trying to make each pen last longer may seem like a way to make an expensive weight loss treatment last a bit longer. But doing so means bypassing the device designed to measure your dose accurately and moving away from the licensed and tested administration instructions.

Risks of using golden dose of Mounjaro:

The main problem with using the Mounjaro golden dose is that you can no longer rely on the pen to measure how much medicine you're taking. Potential risks include:

Taking the wrong amount of Mounjaro

If you withdraw the golden dose using a syringe, you have to measure the leftover medicine yourself rather than relying on the KwikPen to do this for you. Accurately measuring such a small volume can be difficult, so you may inject too much or too little.

Forcing or breaking the pen mechanism also bypasses its normal dose measurement. Because the pen was not designed or tested to deliver a fifth dose, you cannot rely on it to deliver the same measured 0.6ml volume as one of the four intended doses.

Disrupting your Mounjaro dosing schedule

Your Mounjaro dose and weekly dosing schedule are designed to keep treatment consistent from one week to the next. Taking more or less Mounjaro than prescribed can disrupt this schedule.

Because a normal injection is only 0.6ml, even a small difference in the volume of liquid you inject can change how much Tirzepatide you receive. The higher the strength of your pen, the more Tirzepatide each 0.1ml contains and the more you could disrupt dosing.

• If you receive too little, you may have less medicine in your body than intended, which could affect how well your treatment works. Returning to your usual dose the following week may also create a larger change between doses, potentially making treatment harder to tolerate.

• If you take too much, you may be more likely to experience side effects of Mounjaro, particularly gastrointestinal symptoms such as nausea, vomiting or diarrhoea. You have to increase the Mounjaro dose gradually to help prevent this from happening (1).

If you're unsure how much you've taken, it can also be difficult to know what to do when your next weekly dose is due.

Contamination and injection injury risks

Some methods of extracting the golden dose involve withdrawing the medicine from the pen and injecting it with a separate syringe. If you're used to giving yourself Mounjaro with a KwikPen, using a syringe is a different way of giving an injection and may be unfamiliar to you.

It also introduces additional handling and injection steps, which may increase the opportunity for contamination or accidentally hurting yourself with the needle.

Can you use the golden dose of Mounjaro?

You should not use the golden dose of Mounjaro, even if there appears to be enough medicine left in your pen. The only safe way to use Mounjaro is exactly as prescribed: four measured doses from each KwikPen, followed by a new pen for your next scheduled injection.

We understand that throwing away medicine can feel wasteful, particularly when Mounjaro is an expensive treatment. However, the liquid left in the pen is not an extra measured dose, so using it to make your prescription last longer could mean receiving the wrong amount of Mounjaro.

What should you do instead of using the Mounjaro golden dose?

Once you have taken four weekly doses from your Mounjaro KwikPen, dispose of the pen as instructed and start your next prescribed pen when your next dose is due (1,2).

If the cost of continuing treatment is becoming difficult to manage, speak to your prescriber or pharmacy rather than trying to stretch each pen beyond its four intended doses. They can discuss your treatment with you and help you understand the options available.

You can also read our guide to finding the cheapest Mounjaro in the UK for advice on comparing treatment costs safely.

For more advice on using your treatment correctly, read our Mounjaro dosage guide.

References

• Eli Lilly and Company Limited. Mounjaro KwikPen 10mg solution for injection in pre-filled pen - Summary of Product Characteristics (SmPC) - (emc) [Internet]. Electronic Medicines Compendium.

• Eli Lilly and Company Limited. Troubleshooting common Mounjaro (tirzepatide) KwikPen questions. Lilly Medical UK. 2025.

• Eli Lilly and Company Limited. How to use the Mounjaro (tirzepatide) KwikPen. Lilly Medical UK. 2025.