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
Can You Stop Taking Mounjaro?
Yes, you can stop taking Mounjaro (tirzepatide), but it's important to do so safely and with guidance from your prescriber. Unlike some medications, Mounjaro does not require a gradual taper in most cases — you can typically stop at any time. However, understanding what happens after you stop, how to maintain weight loss, and your access options in the UK will help you make an informed decision about 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.
What Happens When You Stop Mounjaro
When you stop taking Mounjaro, your body gradually returns to its normal appetite regulation over several weeks. Most people experience increased appetite within 1–4 weeks of stopping, as the GIP and GLP-1 receptor effects wear off. This doesn't mean the weight will immediately return — weight regain depends on diet, activity level, and whether you've maintained lifestyle changes alongside the medication.
Clinical evidence suggests that without ongoing lifestyle support, some weight regain is common. The amount varies significantly between individuals. Your GP or prescriber can discuss what to expect based on your personal health situation. If you're thinking about stopping, discuss your reasons first — whether it's side effects, cost, or concerns about dependency — as there may be alternative solutions, such as dose adjustment or switching to a different weight loss medication like Wegovy (semaglutide).
- Appetite typically increases within 1–4 weeks
- Weight regain is not automatic but requires ongoing lifestyle management
- Always inform your prescriber before stopping
- Some people restart treatment; others maintain loss through diet and exercise alone
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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.
Accessing Mounjaro: NHS vs Private Routes in the UK
NHS access: Mounjaro is available through NHS specialist tier 3 weight management services, but access is limited and varies significantly by region. Many areas have waiting lists of several months or longer. Your GP can refer you to a local specialist service, though not all GPs will do so routinely — ask specifically about referral to weight management services.
Private access: Mounjaro is available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. This route typically costs between £129–£320 per month depending on your dose, with faster access than NHS routes. You do not need an NHS referral. When you decide to stop, you simply stop purchasing — there's no requirement to continue if it's no longer right for you.
Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, helping you weigh up whether treatment aligns with your health goals before starting or continuing.
- 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 you need to taper off Mounjaro gradually?
No — most people can stop Mounjaro immediately without tapering. Unlike some medications, there's no medical requirement to reduce your dose slowly. However, always inform your prescriber before stopping so they can discuss what to expect and provide post-treatment support.
Will you gain all the weight back after stopping Mounjaro?
Not automatically. Weight regain depends on your diet, activity, and whether you've maintained lifestyle changes learned during treatment. Clinical data shows variable outcomes — some people maintain most of their loss, others regain gradually. Your GP can advise based on your individual situation.
Can you restart Mounjaro after stopping it?
Yes, you can restart Mounjaro if you and your prescriber decide it's appropriate. You'd typically begin again at the starting dose (2.5 mg) and titrate upwards over several weeks, even if you've previously taken higher doses.
What's the cost difference between NHS and private Mounjaro in the UK?
NHS access is free if you qualify through specialist services, but waiting lists are often long and vary by region. Private access typically costs £129–£320 monthly depending on dose. Private routes offer faster access but require payment.
Is Mounjaro better than Wegovy for weight loss?
Both are effective prescription weight loss injections in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show similar average weight loss. Choice depends on individual response, side effects, cost, and prescriber assessment. Your prescriber can advise which is more suitable for you.
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.