Switching From Wegovy to Mounjaro: A Comprehensive Guide

Exploring the Landscape of Weight Loss Injections

Wegovy and Mounjaro are two drugs that were recently licensed for chronic weight management in the UK. Other weight loss medications include Saxenda (containing the active ingredient liraglutide) which was previously the only weight loss injection available in the UK.

Wegovy is the brand name for semaglutide, a medication that's also used to treat type 2 diabetes. Clinical trials have demonstrated that 85% of patients using Wegovy for 68 weeks or more lost at least 5% of their body weight.

Mounjaro is another medication that was originally used as a treatment for type 2 diabetes, but was also found to have impressive weight loss results. This injection was only licensed for weight loss at the end of 2023, but can be really effective. In scientific studies, 91% of people on the highest dose lost 5% or more of their body weight.

Active Ingredients

Semaglutide is the active ingredient in Wegovy. This drug mimics a hormone that's released when we eat: glucagon-like peptide 1 (GLP-1). GLP-1 slows down how fast the stomach empties, helps regulate blood sugar levels and sends signals to the brain.

By tricking the brain into thinking we're full, we're more likely to eat less and lose weight as a result.

Mounjaro contains the active ingredient tirzepatide, which also mimics the hormone GLP-1. However, this drug is also similar in structure to another hormone called glucose-dependent insulinotropic polypeptide (GIP).

GIP is released when food enters the gut and is also involved in blood sugar regulation and fullness signals. Tirzepatide is unique as it's the only drug that mimics both GIP and GLP-1.

Deciding to Switch: Weighing the Options

Wegovy is an effective weight loss injection, and many people experience impressive weight loss results. However, if you're experiencing side effects whilst taking Wegovy, you may be considering alternative options.

Alternatively, some people considering switching from Wegovy to Mounjaro as they think it will give them better weight loss results. This may be because the drug is newer, or because they've heard it's more effective.

Everyone's weight loss journey is different. Mounjaro and Wegovy aren't suitable for everyone, due to pre-existing medical conditions and personal circumstances. It's important to discuss your individual suitability for either medication with a healthcare professional, like the team at Quick Meds.

Mounjaro Vs. Wegovy: What to Know

While the active ingredients in Wegovy and Mounjaro are different, they act in similar ways. Both Wegovy and Mounjaro can help you lose weight, but Mounjaro achieves this by targeting two pathways (GIP and GLP-1) rather than just one (GLP-1).

Both weight loss medications are given as weekly injections under the skin - usually in the fleshy part of the stomach, front of the thigh, or underneath the upper arm. Different doses are used for each drug, though.

Mounjaro is available in 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, and 15mg dose strengths. The different doses of Wegovy are 0.25mg, 0.5mg, 1mg, 1.7mg, and 2.4mg. With Wegovy, the aim is to gradually increase the dose every 4 weeks until the maximum strength is reached. With Mounjaro, the aim is to increase the dose and maintain on either 5, 10 or 15mg therefore you may not need to ever take the higher doses.

Side effects are very similar for both Mounjaro and Wegovy, with gastrointestinal symptoms being the most common, affecting 1 in 10 people. This includes things like nausea, vomiting, diarrhoea, constipation, and abdominal pain. Generally, these symptoms improve once your body adjusts to the medication.

More serious side effects are rare, affecting fewer than 1 in 1000 people, but include things like gallstones, pancreatitis, and low blood sugar. Occasionally, these medications can cause an allergic reaction, which very rarely leads to anaphylaxis and requires emergency care.

Currently, no clinical trials have directly compared Wegovy to Mounjaro. However, some review articles have compared individual studies on each weight loss drug.

When comparing patients taking each medication, 56.7% of people taking 15mg of Mounjaro (the highest dose) lost 20% or more of their body weight. Of those on the highest dose of Wegovy (2.4mg), only 30% lost 20% or more of their body weight.

Overall, this review found that Mounjaro may be more effective at supporting weight loss than Wegovy.

Evaluating Your Current Treatment Plan

When considering how well your current Wegovy treatment plan is going, it's important to see it as just part of your weight loss journey. Any weight loss medication is only effective alongside increased physical activity and diet changes.

Research suggests that weight-loss drugs can help people lose 5-10% of their body weight in 6 months. However, everyone is different - try to set realistic goals that are achievable for you.

As with any medication, it's important to be aware of potential side effects when taking Wegovy. If you've been on the same dose for a while but are still experiencing side effects, it may be a sign that the drug is not working for you. It might help to increase the dose more slowly, try a different type of medication, or stop taking weight loss medication completely.

It's essential to work with healthcare professionals when assessing the effectiveness of your treatment and to avoid switching medications on your own. This can be risky and may lead to potential side effects.

Healthcare professionals can also provide advice on improving your lifestyle, losing weight safely, and offer psychological support if needed.

The Switching Process: What to Expect

How to Stop Wegovy

Your healthcare provider will advise you on how to safely stop taking Wegovy. For many people, there's no need to gradually reduce the dose, and they can stop taking the medication immediately.

After a week or so, any side effects from the medication should wear off. Of course, the positive effects of the drug will also wear off, and you may notice your appetite increasing.

How to Start Mounjaro After Wegovy

Before making the switch, talk to your healthcare provider to ensure that it's suitable for you. Do not stop, start, or switch any of your treatments without discussing it first.

Wegovy and Mounjaro cannot be used simultaneously. You should stop Wegovy before starting Mounjaro.

When you start Mounjaro after stopping Wegovy, you will need to begin with the lowest dose and gradually increase it. This is regardless of your current dose of Wegovy. This is an essential part of your weight loss treatment that helps to minimise side effects as your body adjusts to the new medication.

Mounjaro and Wegovy have different dosing schedules and strengths. Only Wegovy doses are increased every 4 weeks until the maximum dose (the maintenance dose) of 2.4mg is reached. Mounjaro however, can be maintained at 5mg, 10mg or 15mg therefore you may not need to go onto a higher dose if the preceding dose is working sufficiently at suppressing your appetite and helping you lose weight.

Try to remember that the body may need time to adjust to the new medication. More than 1 in 10 people experience mild side effects like constipation, nausea, and stomach pain. Individual responses vary, so it's important to be patient and communicate any concerns or changes with your healthcare provider. This is also why you will be initiated at the lowest dose.

Working closely with your healthcare provider throughout this process helps to ensure a safe and effective transition. Always follow their guidance and recommendations to manage the switch from Wegovy to Mounjaro.

Monitoring Progress and Potential Risks

Scheduling regular check-ups with your healthcare professional allows them to monitor your progress and manage any side effects you're experiencing on the new medication. They can then adjust your dosing schedule to limit any side effects going forward.

Similarly to Wegovy; nausea, vomiting, diarrhoea, constipation and indigestion are common side effects of Mounjaro. If you experience any more worrying side effects, your healthcare provider can help advise you on what to do next.

Beyond the Medications: Holistic Weight Management

Diet and exercise remain key. For sustainable and significant weight loss, it's not enough to rely on medications alone. Healthy eating and regular physical activity are also essential.

This includes a balanced, reduced-calorie diet along with exercise that raises your heart rate several times a week. Read more information on the importance of exercise and diet for weight loss here.

A healthy lifestyle doesn't just help with weight loss but helps you avoid (and improve) any weight-related health condition like type 2 diabetes, heart disease, high blood pressure and high cholesterol.

Summary

It's possible to switch from Wegovy to Mounjaro if you would like to try an alternative weight loss medication or you're experiencing side effects. However, this should only done with the help and advice of a healthcare provider and would always be started at the lowest dose, regardless of whether you have used any other weight loss treatment before.

Looking to discuss your weight loss journey with a professional from the comfort of your own home? At Quick Meds, we offer free online weight loss consultations to help you meet your weight loss goals safely. Click the button below to get started.