The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Taking a Break From Mounjaro — What You Need to Know
If you're considering a break from Mounjaro (tirzepatide), it's important to understand what happens when you pause treatment and how this differs from alternatives like Wegovy. Taking a break from any weight loss medication should always be discussed with your prescriber first, as stopping suddenly can affect your weight management progress and how your body responds when you restart. This guide explains the key considerations and how Mounjaro compares to other GLP-1 options if you're thinking about switching or pausing your treatment.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Why Pause Mounjaro and How It Compares to Wegovy
People pause weight loss medications for various reasons: side effects, cost, reaching a goal weight, or wanting to assess whether they maintain results independently. When you take a break from Mounjaro (tirzepatide), your body gradually stops responding to the dual GIP and GLP-1 mechanisms that help suppress appetite and regulate blood sugar. Unlike Mounjaro's dual-action approach, Wegovy (semaglutide) is a GLP-1-only receptor agonist, meaning it works through a single hormone pathway rather than two.
In clinical trials, Mounjaro achieved approximately 15–21% average body weight loss at maximum dose, whilst Wegovy showed around 14.9% average weight loss. Both require a UK prescription and clinical assessment. If you're pausing Mounjaro and considering Wegovy as an alternative, your prescriber will need to evaluate your individual response and suitability — there's no automatic crossover. Some people find one medication suits them better than the other depending on side effects, weight loss response, or cost. Our GLP-1 weight loss calculator can help you explore projected outcomes at different doses if you're comparing options.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
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When to Pause and What Your Prescriber Needs to Know
Never stop Mounjaro abruptly without guidance from your prescriber. If you experience severe side effects, your GP or the prescriber managing your treatment should assess whether to reduce your Mounjaro dose titration, pause temporarily, or switch to an alternative. Some people pause for a few weeks to allow side effects like nausea or gastrointestinal symptoms to resolve, then restart at the same or lower dose.
If you're thinking about switching to Wegovy after a Mounjaro break, your prescriber will assess your eligibility separately — the two medications have different mechanisms and some individuals respond better to one than the other. Weight regain is common when any weight loss injection is paused, so maintaining the diet and exercise changes you've built is crucial. Keep track of your progress using our free progress tracker to monitor what happens during any break and help your prescriber make informed decisions about restarting or switching treatment.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
What happens to my weight if I take a break from Mounjaro?
Weight regain is common when you pause any weight loss injection because appetite-suppressing effects wear off as the medication leaves your system. The rate varies by individual and how long you've been off treatment. Your prescriber can advise on maintaining the lifestyle changes you've made whilst on Mounjaro to minimise regain.
Can I switch from Mounjaro to Wegovy if I want a break?
Potentially, yes — but this requires a new clinical assessment from your prescriber. Wegovy (semaglutide) is a single GLP-1 mechanism rather than Mounjaro's dual GIP+GLP-1 approach, so suitability is individual. Some people find Wegovy has fewer side effects; others prefer Mounjaro's dual action. Your prescriber will determine if switching is appropriate for you.
How long can I safely take a break from Mounjaro?
This depends on your individual situation and should be discussed with your prescriber. Short breaks of a few weeks are sometimes used to manage side effects, whilst others pause for months. There's no universal safe duration — your GP or prescriber will advise based on your health, weight management goals, and any comorbidities.
Will I need to restart Mounjaro at the same dose after a break?
Not necessarily. Your prescriber may restart you at a lower dose and titrate up gradually if you've been off treatment for a long time, or restart at your previous maintenance dose if the break was brief. This decision depends on how your body responds and any changes in your health since you paused.
What's the difference between pausing Mounjaro and switching to Wegovy?
Pausing means stopping all treatment temporarily; switching means moving to a different medication. Mounjaro uses dual GIP+GLP-1 mechanisms whilst Wegovy uses GLP-1 only. Switching requires a new clinical assessment and may be prescribed if you had side effects on Mounjaro or want to try an alternative approach to weight management.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.