Mounjaro Golden Dose (The Extra 5th Dose)

The “Mounjaro golden dose” (sometimes called the “fifth dose”) is a term used online to describe the small amount of liquid left in a Mounjaro pen after the four prescribed injections have been used.

This leftover medication is not an extra dose. The pen is manufactured with a small intentional overfill to ensure that each of the four injections delivers the correct, full dose. Once all four doses of Mounjaro have been taken, the pen should be disposed of.

Importantly, the remaining liquid has not been measured, tested, or approved to be used as another injection.

On platforms such as TikTok and Reddit, some users show ways to extract the leftover liquid from a Mounjaro pen using needles, syringes, or by forcing the pen mechanism.

These videos often suggest that this is a way to “save money” or “avoid wasting medication”.

However, this practice is unsafe and not recommended.

Key concerns with these methods include:

• The extraction process is not sterile
• Household needles or syringes are not designed for this purpose
• There is no reliable way to know how much medication is being drawn up
• The pen was never intended to deliver a fifth dose

This content shared online does not reflect medical guidance, pharmacy standards, or manufacturer instructions.

Using the golden dose carries several important risks:

Not sterile

Extracting medication outside of the pen’s normal mechanism increases the risk of contamination and infection.

Medication stability

Once a Mounjaro pen is in use, it should be discarded after 30 days. Any leftover liquid may no longer be sterile or stable.

Incorrect dosing

The amount left in the pen is unknown and inconsistent, which can result in:

• Underdosing (most common)
• Overdosing
• Unpredictable effects

Disrupted treatment progress

Underdosing can reduce appetite suppression and slow weight-loss progress, while overdosing dosing can increase side effects and interfere with your routine.

Outside prescribing guidance

Using leftover medication in this way is not supported by clinical trials, manufacturers, or healthcare professionals.

The Mounjaro “golden dose” is not safe, not measured, and not approved for use. The leftover liquid in the pen exists only to ensure accurate delivery of the four prescribed doses.

For your safety and to protect your progress:

• Use Mounjaro exactly as prescribed
• Dispose of the pen after all four doses are taken
• Speak to your pharmacist or prescribing clinician if your current dose does not feel effective