Switching from Wegovy to Mounjaro

Prescription weight-loss medications have changed how obesity and metabolic health are managed, particularly for people who have struggled to lose weight through lifestyle changes alone. As newer weight loss treatments emerge, it’s natural for patients to ask whether switching medications could improve results or reduce side effects.

One of the most common questions GPs now hear is whether switching from Wegovy to Mounjaro makes sense. While both medications are injectable treatments designed to support weight loss, they are not identical, and switching between them requires careful medical consideration.

This article explains what Wegovy and Mounjaro are, why someone might consider switching, who may be eligible, and how a New Zealand doctor can help manage the transition safely.

What are Wegovy and Mounjaro?

Wegovy contains semaglutide, a medication that mimics a naturally occurring hormone called GLP-1 (glucagon-like peptide-1). GLP-1 helps regulate appetite, slows stomach emptying, and increases feelings of fullness. Wegovy is approved in New Zealand for weight management through private prescription pathways.

Mounjaro contains tirzepatide, which works slightly differently. It targets two hormone receptors instead of one: GLP-1 and GIP (glucose-dependent insulinotropic polypeptide). By acting on both pathways, tirzepatide can have a stronger effect on appetite regulation and blood-sugar control in some people.

Although both medications aim to support weight loss, they are not interchangeable without medical oversight.

Why switch from Wegovy to Mounjaro?

There are several reasons a person may ask about switching medications, but it’s important to understand that switching is not automatically better or necessary.

Some common reasons patients explore switching include:

• Limited weight loss response after several months on Wegovy

• Weight-loss plateau, despite good adherence to treatment

• Side effects that remain problematic even after dose adjustments

• Metabolic considerations, such as insulin resistance or type 2 diabetes

• Emerging clinical evidence suggesting alternative options may be suitable

It’s also worth noting that individual response to weight-loss medication varies significantly. Some people respond very well to semaglutide, while others may not experience the same degree of appetite suppression or weight change.

A GP’s role is to help determine whether switching is medically appropriate, rather than driven by expectations alone.

Who can switch from Wegovy to Mounjaro?

Not everyone taking Wegovy would be a suitable candidate for switching medications.

Eligibility depends on factors such as:

• Current Wegovy dose and duration of use

• Weight-loss progress and overall health outcomes

• History of side effects or intolerance

• Other medical conditions (such as pancreatitis or gallbladder disease)

• Other medications being taken

Switching should only be considered after a structured review with a doctor who understands your full medical history and treatment goals.

How to switch safely

Switching between injectable weight-loss medications is not as simple as stopping one and starting another at full dose.

A safe transition typically involves:

• Completing your last scheduled Wegovy dose

• Allowing an appropriate gap before starting a new medication

• Beginning at a low starting dose of the new treatment

• Gradually increasing the dose over time

This approach reduces the risk of gastrointestinal side effects such as nausea, vomiting, reflux, or dehydration. Starting too high or overlapping medications can increase discomfort and reduce adherence.

Medical guidance ensures the switch is structured and tailored to your body’s response.

Medical guidance and monitoring

Ongoing monitoring is a key part of any weight-loss treatment, particularly during medication changes.

Your GP may monitor:

• Weight and body-composition trends

• Appetite and eating behaviours

• Side effects and tolerance

• Energy levels and hydration

• Blood-sugar markers, where relevant

Follow-up appointments allow your doctor to adjust treatment early if issues arise and to confirm whether the new medication is meeting expectations.

At Pocket Lab, our online GPs provide structured reviews and ongoing support for patients considering switching from Wegovy to Mounjaro, ensuring decisions are evidence-based and patient-specific.

Frequently asked questions

Will switching guarantee better weight loss?

No. While some people respond better to one medication than another, results vary.

Do I need a break between medications?

Yes. A short gap is usually recommended to reduce side-effect risk.

Can I switch on my own?

No. Switching without medical supervision is not recommended.

Is switching common?

It’s becoming more common as new medications emerge, but it should always be GP-led.

Availability in New Zealand

Wegovy and Mounjaro are now both currently available in NZ for weight-loss treatment.

Final note for NZ patients

Switching weight-loss medications should never be rushed or self-directed. The safest outcomes come from personalised GP care, realistic expectations, and ongoing monitoring.

Mounjaro and Wegovy are now both available in NZ — you can take this FREE eligibility quiz to see if it is right for you.

Check Your Eligibility