Can you split a Mounjaro pen into smaller doses across several days?
No, you cannot safely split a Mounjaro pen into smaller doses across several days for weight loss, as the manufacturer Eli Lilly and UK healthcare providers strongly advise against it due to risks like inaccurate dosing, contamination, and reduced effectiveness. Mounjaro pens are pre-filled with 4 fixed weekly doses (starting at 2.5mg for weight loss, increasing gradually up to 15mg), designed for one injection per week over four weeks per pen, and splitting them lacks official safety data. Always follow your prescriber's advice to avoid side effects and ensure proper weight loss results.
- Official stance: The manufacturer and clinicians say no, pens are fixed-dose and splitting risks contamination, infection, and wrong amounts that slow weight loss.
- Why people consider it: To save money or stretch supplies, but it's unsafe without medical supervision.
- UK pen details: One pen gives four weekly doses; use as prescribed, consulting your doctor for any changes.
This text has been fact-checked for accuracy by Sorin Romaniuc, Pharmacist at medino.