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
Free tracker included with every download this week
What Are Mounjaro Withdrawal Symptoms?
When you stop taking Mounjaro (tirzepatide), your body may experience changes as it adjusts to the absence of the medication. Unlike some medications, Mounjaro does not typically cause physical withdrawal in the clinical sense, but many people notice their appetite returns and weight loss benefits gradually reverse. Understanding what to expect when stopping—and how to access Mounjaro in the UK through NHS or private routes—helps you make informed decisions about your weight management journey.
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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.
Understanding Changes After Stopping Mounjaro
Mounjaro is not addictive, and stopping it does not cause withdrawal symptoms like those from certain other medications. However, when you discontinue tirzepatide, several changes commonly occur: appetite typically returns to normal within days or weeks, food cravings may increase, and you may feel less full after meals. Many people notice their weight begins to increase again if they do not maintain the dietary and lifestyle changes they adopted while on the medication. This is why Mounjaro works best alongside sustained reduced-calorie eating and increased physical activity—the medication supports these changes, but does not replace them. Some users report temporary changes in energy levels or mood as their body readjusts, though these are not true withdrawal effects. Your GP can discuss a tapering plan if you decide to stop, though Mounjaro does not require gradual dose reduction like some medications do. The most important step is maintaining the healthy habits you developed whilst taking the injection.
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.
NHS vs Private Access and Costs in the UK
In the UK, you can access Mounjaro through NHS specialist weight management services or via private prescription through an online GP. NHS access requires referral to a tier 3 or tier 4 weight management service, which can involve waiting lists of several months or longer depending on your region. Private prescription costs typically range from £150 to £300 per month, depending on your dose—starting doses (2.5 mg) are generally cheaper than higher maintenance doses (15 mg). Private routes involve a brief online consultation with a UK-licensed prescriber who will assess your eligibility based on your BMI and health conditions. If prescribed, your prescription is dispensed by a GPhC-registered pharmacy. Use our GLP-1 weight loss calculator to estimate potential outcomes at different doses, and our BMI calculator to check your current BMI and eligibility threshold—this helps you understand what to discuss with a prescriber.
- 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.
Do I experience withdrawal when I stop taking Mounjaro?
No, Mounjaro does not cause clinical withdrawal like some medications. However, appetite typically returns within days to weeks, cravings may increase, and weight loss benefits gradually reverse if you do not maintain lifestyle changes. Your GP can advise on stopping safely.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £150 to £300 per month depending on your dose. Starting doses (2.5 mg) are cheaper than higher maintenance doses. Prices vary slightly between private prescribers and dispensing pharmacies.
Can I get Mounjaro on the NHS in the UK?
Yes, Mounjaro (tirzepatide) is approved by NICE for NHS use through specialist tier 3 or tier 4 weight management services. Access requires GP referral and can involve waiting lists of months or longer, depending on your region and local NHS capacity.
What happens to my weight after stopping Mounjaro?
Weight typically begins to increase again if you return to previous eating habits. Mounjaro works alongside lifestyle changes—maintaining a reduced-calorie diet and physical activity helps prevent rapid weight regain after stopping the medication.
How do I know if I'm eligible for Mounjaro in the UK?
You are typically eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions like type 2 diabetes, hypertension, or sleep apnoea. Your GP or a private prescriber will assess your individual eligibility.
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.