Switching from Mounjaro to Wegovy

NEWS · 3 minute read

Written by Rahul PuriPharmacist, MPharm

Medically reviewed 7 October 2026

Switching from tirzepatide to semaglutide needs a prescriber’s individual plan. These medicines and their doses are not interchangeable. An online article should not be used as a universal switching schedule.

Start with the reason for changing

Cost, availability, tolerability and your response may all prompt a review. Explain the specific difficulty rather than choosing a new medicine solely from a comparison of trial percentages. Ask what alternatives are appropriate, including changes to the wider support plan.

Illustration of a private weight-management consultation — Prepare your treatment history and questions for an individual review. Illustrative image.

What information does the prescriber need?

The exact medicine, dose and date of your last injection.
How long you have used it and any interruptions.
Your weight trend, food and fluid intake, and side effects.
Other medicines, health conditions and relevant changes in circumstances.

Why is there no universal dose conversion?

Products have different instructions and treatment histories differ. The receiving plan must be agreed clinically. Do not copy a fixed waiting interval or restart schedule from another patient, and do not use two treatments together unless this has specifically been assessed and prescribed.

Ask for written instructions and a contact route if the change does not go as planned. The tirzepatide prescribing information is a reference, not a substitute for your clinician’s switching decision.

A balanced meal with protein, vegetables and grains — An individual care plan should address nutrition as well as weight change.

What results should you expect?

There is no guaranteed plateau duration, improved tolerability or weight-loss percentage after switching. Review the response over the agreed period and discuss concerns. Comparing averages from different trials cannot predict how a particular person will respond to a change.

Discuss your weight-management care

Complete Puri Pharmacy’s confidential assessment to ask about suitable support, starting care or changing provider. A clinician reviews your information before any treatment decision. This is not an urgent-care route.

Start my weight-management assessment

For the wider care pathway, read about Puri’s weight-management service.

Switching from Mounjaro to Wegovy

No, wait 7 days between your last Mounjaro dose and your first Wegovy dose.

From September 2025, Mounjaro costs between £160–£320 per pen, while Wegovy remains a more cost-effective option for many patients. However, treatment choice should be based on individual health needs, not just price.

Clinical trials show that Mounjaro may deliver slightly greater average weight loss (around 22.5%), while Wegovy achieves 15–21%. With the new 7.2mg Wegovy dose expected in late 2025, results are likely to be very similar.

Take your final Mounjaro injection.
Wait 7 days (washout period).
Begin Wegovy at 0.25mg once weekly.
Increase the dose gradually every 4 weeks (0.5mg → 1mg → 1.7mg → 2.4mg).
Higher doses up to 7.2mg may be available in late 2025.

Some patients notice a short plateau of 2–3 weeks while the body adjusts, but long-term results with Wegovy remain strong, up to 21% weight loss when used correctly.

Mounjaro: dual action on GLP-1 + GIP receptors, often stronger appetite suppression.
Wegovy: GLP-1 only, licensed in the UK for obesity and heart protection, with fewer side effects in many patients.

No. At Puri Pharmacy, we never force or recommend switching based on price alone. Every consultation is personalised, considering your medical history, treatment response, and goals.

Yes. At Puri Pharmacy, you can access Wegovy both in-person at our Southall & Hillingdon branches or via our nationwide service with secure home delivery.