Yes, Mounjaro (tirzepatide) should ideally be refrigerated to maintain its effectiveness.
According to Eli Lilly, the manufacturer, you should store your Mounjaro pens in the refrigerator at a temperature between 36°F and 46°F (2°C to 8°C). Proper storage ensures the drug remains chemically stable and safe to inject until its expiration date.
While refrigeration is ideal, Mounjaro can safely remain at room temperature for a limited time. You can keep your pens unrefrigerated at temperatures up to 86°F (30°C) for a maximum of 21 days. This flexibility is helpful if you are traveling or accidentally leave a pen out of the fridge.
However, if a pen has been out of the refrigerator for longer than 21 days, it should be discarded, even if there is still medication inside. It is also vital to keep the pens in their original carton to protect the medicine from light.
Never freeze Mounjaro. If a pen becomes frozen, do not use it — even if it thaws later — as extreme cold can break down the active proteins in the drug.
If Mounjaro is exposed to temperatures higher than 86°F or direct sunlight, the medication may begin to degrade.
When tirzepatide (Mounjaro’s active ingredient) breaks down, the drug may become less effective.
Before injecting, always check the liquid inside the pen. It should be clear and colorless to slightly yellow. If you notice any cloudiness, particles, or discoloration, it’s best to consult a healthcare professional before proceeding with your dose.
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