Written by: Isabel Finch
Published: August 18, 2025
Alternative obesity management treatments available
Mounjaro is an effective weight loss treatment – but it’s not right for everyone. Planned Mounjaro UK price increases have left some patients concerned about the cost of the treatment. Others find the medication just doesn’t agree with them.
So, if you’re on Mounjaro, you might be thinking about switching to Wegovy, another GLP-1 weight loss medication used for weight management. But how can you do this safely?
Here, we explain what the process involves, with the help of our Lead Pharmacist Aamina Rafiq.
Wegovy and Mounjaro are both weekly injections that work in similar ways. The active ingredient in Wegovy is semaglutide. However, Mounjaro contains tirzepatide.
Both medications are known as glucagon-like peptide-1 (GLP-1) receptor agonists. They mimic the hormone GLP-1, which sends messages to your brain to let you know you are full. They also slow down the rate food leaves your stomach. So you feel fuller quicker – and for longer.
However, Mounjaro is a dual agonist. This means it targets two hormones: GLP-1 and glucose-dependent insulinotropic polypeptide (GIP).
Because Mounjaro is a dual agonist that also mimics GIP, it can have a stronger effect. In clinical trials, patients lost an average of 22.9% of their body weight after 3.5 years on Mounjaro, compared to an average of 16.7% after 2 years on Wegovy.
But some users report stronger side effects on Mounjaro. And the cost of Mounjaro is higher. Its manufacturer, Eli Lilly, has announced a 170% price rise starting 1 September, 2025.
Our Wegovy vs Mounjaro article goes into more detail about the differences between the two medications.
Yes. You can start Wegovy after Mounjaro. You’ll just need to take a short, one-week break (called a “washout period”) after stopping Mounjaro before you can start using Wegovy.
“This short pause is a really important step to make sure the switch is safe and your body has time to adjust,” explains Aamina Rafiq, Lead Pharmacist at Simple.
You need to take a short, one-week break before you start using Wegovy. So if you take your last dose of Mounjaro on a Monday, you can start Wegovy the following Monday.
This advice is the same no matter what dosage of Mounjaro you’re currently taking. This short pause is designed to reduce the risk of side effects.
“The reason we ask patients to take this break is to keep you safe,” says Aamina. “If you overlap two GLP‑1 medications, your body ends up adjusting to both at the same time. That can increase the risk of unpleasant side effects like nausea or vomiting, and in some cases, more serious complications.”
Yes. When you switch from Mounjaro, you don’t necessarily have to start Wegovy on the lowest dose. Instead, you may be able to start on a higher dose of Wegovy straight away.
Our clinical team will help you find the Wegovy dose that best suits you. We’ll base this on your current Mounjaro dosage, how well you tolerate the medication and your results so far.
The table below shows the recommended Wegovy dose, based on your current Mounjaro dose. You can also choose to start on a lower dose of the medication, if you’d prefer.
| Current Mounjaro Dose | Recommended Wegovy Dose |
| 2.5 mg | 0.25 mg |
| 5 mg | 0.5 mg |
| 7.5 mg | 1 mg |
| 10 mg | 1 mg |
| 12.5 mg | 1.7 mg |
| 15 mg | 1.7 mg |
Most patients find they experience similar side effects on different GLP-1 medications. However, you might notice that side effects, like nausea and fatigue, get better when they switch to Wegovy. But every person responds to the treatment differently.
Some people notice changes in side effects when their dose increases or when their dosing schedule is adjusted.
“If you’re concerned about your weight loss progress, it’s worth remembering weight care isn’t always a straight line,” says Aamina.
“Small changes or plateaus are completely normal. What matters is that you keep building healthy routines with your food, movement, and daily habits, while letting the medication support you along the way.”
It’s really important to know that you’re not alone in making your decision. And no matter what medication you decide to use, we can support you throughout your journey. Our clinical team can help tailor your dosing schedule and support long-term weight management. If you need guidance, call our team on 0141 774 5023 or contact us here.
“Our role is to make this process as simple as possible for you,” says Aamina. “When you switch with us, you’ll receive guidance from our clinical team, reminders when it’s time to reorder, and access to resources designed to help you stay on track.
“We also know medication is only one part of the picture. That’s why we provide advice articles on nutrition, exercise, and building the mindset that supports lasting results. Patients who combine medication with these lifestyle habits often feel more confident and in control of their journey.”
You can visit our online doctor weight loss clinic to see what weight loss options are available to you.
[elementor-template id=”7540″]Wilding, J.P.H., Batterham, R.L. and Calanna, S. (2021). Once-Weekly Semaglutide in Adults with Overweight or Obesity.The New England Journal of Medicine, [online] 384(11), pp.989–1002. doi: https://doi.org/10.1056/NEJMoa2032183.
Fick, M. (2025) Eli Lilly to hike UK price of Mounjaro weight-loss, diabetes medicines by 170%, Reuters. Available at: https://www.reuters.com/business/healthcare-pharmaceuticals/eli-lilly-hike-uk-price-mounjaro-weight-loss-diabetes-medicines-by-170-2025-08-14/ [Accessed: 14 August 2025].
Editor’s note: This article was originally published on 14 August, 2025 . It has been updated to reflect new clinical guidance on appropriate Wegovy dosage when switching from Mounjaro. Previous advice was to start on the lowest dose of Wegovy, regardless of your last Mounjaro dose. Updated clinical guidance now states that patients may be able to switch to a higher dose of Wegovy straight away.
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