weight loss
∙6 minute read
If you’ve been reading the news lately, you’ll know that switching from Mounjaro to Wegovy has sparked a lot of discussion. Some people are worried about side effects, others are anxious about losing progress, and plenty of myths are flying around about how the switch works.
Let’s break down the five biggest myths and clear up the facts.
There has been talk about taking weeks off before starting Wegovy, but this isn’t always necessary.
The truth is that whether you need a break or not depends on your individual situation, and your clinician will guide you through that decision. In many cases, it’s perfectly safe to move straight across, starting on a dose that suits your history and how well you’ve tolerated treatment so far.
What really matters isn’t following someone else’s schedule, but sticking to a plan that’s tailored specifically to you.
At Numan, we don’t typically advise having a washout period to help protect your progress. A break in treatment isn't typically recommended. However, if you had non-severe side effects, a break may be considered to let these subside before starting you on your new treatment.
It’s true that more people report nausea, bloating, or even vomiting when taking Wegovy, especially if they jump in at too high a dose.1 But that doesn’t mean everyone will struggle.
However, when it comes to side effects, it’s important to remember that your body often just needs time to adapt. Many people notice that symptoms like nausea or bloating improve after the first few weeks of treatment.
One of the best ways to make the transition smoother is by starting on a lower dose and building up gradually, rather than rushing the process. Your clinician may recommend this approach to give your system the chance to adjust at a comfortable pace.1
And while anecdotal evidence can sometimes make it sound like side effects are inevitable or worse with Wegovy, that’s not always the case. Everyone responds differently, and plenty of people find that, once they’ve settled in, Wegovy feels no harder to tolerate than Mounjaro (according to what people say). Your clinician and health coach can support you through the transition to ensure you understand why you may be feeling a certain way and provide you with tips to help keep side effects to a minimum.
A common complaint online is that Wegovy feels “weaker” or less powerful than Mounjaro. Some even worry they’ll undo all their progress by making the switch.
Wegovy has been on the market for longer than Mounjaro, which means there’s already a wealth of real-life experience from people using it around the world.2 Both medicines are supported by strong clinical trial evidence showing significant weight loss when paired with lifestyle changes, but it’s worth remembering that day-to-day results can vary depending on how well you stick to your treatment plan or maintain healthy habits.2,3
Some people notice their weight loss slows after switching to Wegovy, but this isn’t always down to the medication itself. Because there have been very few head-to-head trials comparing Mounjaro and Wegovy, it’s hard to say for certain how they stack up against each other.
What we do know is that Wegovy is not only effective for weight management but also carries the added benefit of reducing the risk of heart disease in people with obesity, something Mounjaro isn’t yet licensed for in the UK.4
It’s no secret that the rising cost of Mounjaro has encouraged many people to look at alternatives. But price isn’t the only factor driving the switch.
Wegovy is available on the NHS for those who meet specific eligibility criteria, making it more accessible for some patients. Others choose it because of its proven heart health benefits, or simply because it’s more widely available, reducing the risk of supply gaps that could interrupt treatment. So while cost plays a part, there are plenty of other valid reasons why someone might opt for Wegovy instead.
Many people worry that moving from Mounjaro to Wegovy will undo all their hard work, as though they’re “back at square one.” But that’s not the case. The lifestyle changes you’ve already made, like improving your eating habits, getting more active, and building healthier routines, don’t disappear just because your medication changes. With the right support, most people transition smoothly and keep moving forward.
According to anecdotal evidence, it’s normal for your weight to fluctuate a little during the switch, but this is often temporary. What really makes the difference is consistency, sticking to your plan around diet, exercise, and treatment. That’s where coaching comes in. Having a coach gives you a framework to protect your progress, not just during your treatment, but for at least 12 months after.
Research shows it takes around 66 days to form a habit, and with coaching, you’ll have support to keep those habits in place.5 No matter which medication you’re on, you’ll be guided to keep the weight off and continue making progress, even if things feel uncertain during the changeover.
Switching from Mounjaro to Wegovy can feel unsettling, especially when online forums are full of mixed experiences. But every journey is individual. Your response to treatment will depend on your body, your health history, and how closely you follow the plan set out with your clinician. What’s most important is remembering that these medications are tools and the biggest drivers of long-term success are the habits you build around them.
Clinical Review. Canadian Agency for Drugs and Technologies in Health; 2022.
Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, et al. Once-weekly semaglutide in adults with overweight or obesity. The New England journal of medicine. 2021;384(11): 989–1002.
Ard J, Lee CJ, Gudzune K, Addison B, Lingvay I, Cao D, et al. Weight reduction over time in tirzepatide-treated participants by early weight loss response: Post hoc analysis in SURMOUNT-1. Diabetes, obesity & metabolism. 2025;27(9): 5064–5071.
Lincoff AM, Brown-Frandsen K, Colhoun HM, Deanfield J, Emerson SS, Esbjerg S, et al. Semaglutide and cardiovascular outcomes in obesity without diabetes. The New England journal of medicine. 2023;389(24): 2221–2232.
Singh B, Murphy A, Maher C, Smith AE. Time to form a habit: A systematic review and meta-analysis of health behaviour habit formation and its determinants. Healthcare (Basel, Switzerland). 2024;12(23): 2488.
Written by Hassan Thwaini
Clinical Pharmacist and Copywriter, Master of Pharmacy (MPharm)
