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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How to Come Off Mounjaro Safely in the UK
Stopping Mounjaro (tirzepatide) should always be done in consultation with your prescriber, not abruptly. Most UK adults can stop at any time, but the way you stop matters for managing weight rebound and side effects. This guide covers the safest approach to discontinuing Mounjaro, what happens after you stop, and how to support sustainable weight management once you've finished treatment. Always speak to your GP or the prescriber who issued your Mounjaro KwikPen before making any changes to your treatment.
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Calculate Your BMI Instantly
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.
How to Stop Mounjaro — Medical Guidance
There is no mandatory tapering schedule for Mounjaro. Unlike some medications, you can stop tirzepatide at any dose without a formal step-down plan — your prescriber will not require you to reduce doses gradually. However, stopping suddenly may mean side effects like nausea resolve quickly, whilst appetite and food intake may increase rapidly within days.
The safest approach is to discuss your reasons for stopping with your prescriber before your next injection date. They can:
- Confirm it is safe for you to stop (especially if you have type 2 diabetes or are on other medications)
- Advise whether a gradual reduction might suit your situation
- Discuss strategies to manage weight rebound after stopping
- Help you plan next steps — whether that is Mounjaro at a lower dose, switching to Wegovy (semaglutide), or lifestyle-focused weight management
Weight regain typically begins within 1–2 weeks of stopping, so having a plan in place before you stop is important.
Clinically BackedWeight Loss
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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.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
What Happens After You Stop — Weight Rebound & Appetite
Most people experience increased appetite and food cravings within days of stopping Mounjaro, as the hormonal effects of tirzepatide wear off. Weight regain is common — clinical evidence suggests many people regain 50% or more of the weight lost within the first year of stopping, though individual experiences vary significantly.
To minimise rebound:
- Maintain calorie awareness: Use our free progress tracker to monitor intake and weight weekly
- Plan structured meals to manage hunger without relying on the medication's appetite suppression
- Increase physical activity — this is particularly important as the appetite-suppressing effect fades
- Seek structured support: Ask your GP about tier 2 or tier 3 weight management services available on the NHS
Weight loss is sustainable only with lasting lifestyle change — the medication was a tool to support that change, not a permanent solution.
- 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.
Can I just stop Mounjaro without telling my prescriber?
Technically yes — Mounjaro is not a medication you become dependent on, and there is no medical risk from stopping suddenly. However, you should always inform your prescriber. They can discuss your reasons for stopping, check whether it is safe given your health circumstances, and help you plan for weight rebound and next steps. This conversation matters.
Will I have withdrawal symptoms when I stop Mounjaro?
No. Tirzepatide does not cause withdrawal in the medical sense. However, gastrointestinal side effects like nausea usually resolve within days of stopping. More significant is the return of hunger and appetite — this is not withdrawal but the restoration of normal appetite regulation. This can be challenging to manage without a plan.
What is the best time to stop Mounjaro?
The best time is when you and your prescriber agree it is right for you. Some people stop after reaching a goal weight; others pause to assess long-term sustainability. Avoid stopping during particularly stressful periods or when support structures are unavailable. Winter months can be harder due to reduced activity and seasonal appetite changes. Plan ahead.
Should I switch to Wegovy instead of stopping completely?
Switching from Mounjaro (tirzepatide — dual GIP/GLP-1 agonist) to Wegovy (semaglutide — GLP-1 only) is possible, though individual results may differ. Some people find Wegovy equally effective; others prefer Mounjaro. Any switch must be managed by your prescriber. An approximate equivalence exists — discuss this with your doctor before making changes.
How do I access NHS weight management support after stopping Mounjaro?
Once you stop, ask your GP for a referral to tier 2 or tier 3 weight management services in your area. Tier 2 includes behaviour change programmes and community support; tier 3 offers multidisciplinary specialist services. Availability varies by region. Use our BMI calculator and GLP-1 weight loss calculator to track your progress whilst on the waiting list.
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.