Does Mounjaro interact with other medications?

Mounjaro (tirzepatide) can interact with other medicines primarily by slowing stomach emptying, which may change how quickly some oral drugs are absorbed. This matters most for medicines with a narrow therapeutic index (for example, warfarin or digoxin), so extra monitoring may be needed when starting or changing tirzepatide doses in the UK.

Combining Mounjaro with insulin or sulfonylureas can increase the risk of hypoglycaemia (low blood sugar). Clinicians often reduce doses of these diabetes medicines and advise closer blood glucose monitoring.

Contraception: UK guidance advises people using oral contraceptive pills to use condoms for 4 weeks after starting tirzepatide and for 4 weeks after each dose increase, or consider a non-oral method, because absorption may be reduced. Vomiting or severe diarrhoea can further reduce pill effectiveness, so follow missed-pill guidance and consider backup contraception.

Many common medicines (e.g., metformin, statins, blood pressure tablets) can be used alongside Mounjaro, but individual checks and monitoring are advised due to possible absorption changes and patient-specific risks. Always tell your prescriber about all medicines and supplements you take.

• Mounjaro can delay absorption of other oral medicines; consider monitoring for drugs like warfarin and digoxin.
• Risk of hypoglycaemia increases if taken with insulin or sulfonylureas; doses may need adjustment and glucose monitoring.
• UK contraception advice: use condoms for 4 weeks after starting tirzepatide and after each dose increase, or choose a non-oral method.
• Vomiting or severe diarrhoea while on tirzepatide can reduce the effectiveness of oral contraception; follow missed-pill guidance.
• Many medicines can be taken with Mounjaro (e.g., metformin), but check for side effects and consider monitoring when starting or changing doses.

Sources

• EMA – Mounjaro (tirzepatide) EPAR: Product Information
• FSRH – GLP-1 agonists and contraception (patient information)
• Coventry & Warwickshire – Medicines Safety Spotlight: Tirzepatide
• BOB ICB – Tirzepatide (Mounjaro) Initiation Guide
• MHRA Drug Safety Update – GLP-1 receptor agonists: safety reminders