Tirzepatide (Mounjaro) explained

Overview

Tirzepatide, sold as Mounjaro, is a dual GIP and GLP-1 receptor agonist. Acting on two incretin pathways generally produces greater average weight loss than a GLP-1 agonist alone.

Why it's done and who it helps

• Dual GIP/GLP-1 action; once-weekly subcutaneous injection.
• Doses step from 2.5 mg through 5, 7.5, 10, 12.5 to 15 mg.
• Each step is normally held for at least four weeks before escalation.
• Recommended by NICE for managing overweight and obesity within a specialist pathway (TA1026).

Dose escalation in practice

The 2.5 mg starting dose is a tolerability dose, not a treatment dose. We escalate only when nausea, reflux and bowel habit are settled, and we hold or step back if they are not.

Who tends to do well

People who combine the medicine with regular protein intake, resistance training and honest weekly weighing generally sustain the best results. Response is reviewed formally at 26 weeks.

Kidney considerations

Tirzepatide is not cleared primarily by the kidneys and no routine dose reduction is specified for reduced kidney function, but dehydration from vomiting or diarrhoea can cause acute kidney injury, so monitoring is tighter in CKD.

Preparing for your appointment

Is Mounjaro better than Wegovy?

On average tirzepatide produces greater weight loss in trials, but the right medicine depends on your kidney status, tolerance, other conditions and cost.

Do I stay on 15 mg forever?

No. We use the lowest dose that maintains your result and tolerability.

When to contact your care team

Contact the clinic promptly if you have any of the following:

• Vomiting or diarrhoea lasting more than 24 hours, or you cannot keep fluids down
• Passing much less urine than usual, or new swelling of the legs or face
• Severe pain in the upper abdomen that spreads to your back, with or without vomiting
• A weight change of more than 2 kg in a week that is not explained by fluid
• A missed weekly weight, a missed dose, or any hospital admission

If you are seriously unwell, contact NHS 111 or your renal unit directly rather than waiting for your next review.

Your care at KidneyWeight Clinic

Every dose change, weekly weight and kidney blood test is recorded in your clinical monitoring record, reviewed by Professor Mohammed Mahdi Althaf at six-weekly intervals and formally reassessed at 26 weeks. Booking and your initial payment are handled by professoralthaf.co.uk, medication supply by Healist Pharmacy, and follow-up appointment payments by Carebit.

References

• NICE TA1026: tirzepatide for managing overweight and obesity
• NICE TA875: semaglutide for managing overweight and obesity
• NICE CG189: obesity identification, assessment and management
• NHS: weight-loss medicines

This article is general patient information reviewed by a consultant nephrologist. It is not individual medical advice; treatment decisions are made at a face-to-face consultation.