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 Happens After You Stop Mounjaro?
Stopping Mounjaro is a common question for people nearing the end of their treatment. After completing your Mounjaro course, your body adjusts gradually, and weight management becomes a personal responsibility again. The NHS recommends continuing the lifestyle changes — reduced-calorie diet and increased physical activity — that supported your weight loss during treatment. Some people maintain their weight loss successfully, whilst others may experience gradual weight regain. Your GP can advise on ongoing support, whether that's continued monitoring, referral to a weight management service, or consideration of alternative approaches. Understanding what to expect helps you plan ahead.
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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.
NHS Guidance on Stopping Mounjaro and Weight Regain
The NHS recognises that stopping any weight loss medication, including tirzepatide (Mounjaro's active ingredient), requires careful planning. Weight regain commonly occurs after stopping GLP-1 or dual GIP/GLP-1 medications — this is a well-documented clinical finding, not a personal failure. Clinical data shows that without continued dietary and activity changes, people often regain 30–50% of lost weight within a year of stopping treatment.
NHS tier 3 weight management services recommend:
- Continuing reduced-calorie eating patterns established during Mounjaro use
- Maintaining regular physical activity (150 minutes moderate intensity weekly, per NHS guidelines)
- Regular GP monitoring of weight, blood pressure, and metabolic health
- Behaviour change support through NHS programmes if available in your area
- Discussion about longer-term weight management strategy before stopping
Stopping abruptly without a plan significantly increases regain risk. Work with your GP or specialist service to create a maintenance strategy before your final dose.
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.
Mounjaro Dose Titration and Treatment Duration
A standard Mounjaro course involves dose titration from 2.5 mg up to your effective dose over 16–20 weeks, followed by a maintenance phase. The length of treatment varies — some people use it for 6–12 months, whilst others continue longer. Your prescriber will assess whether continuing treatment is appropriate for your individual health and weight loss goals. This decision is usually made at your regular reviews. If you're approaching the end of your course, discuss maintenance plans now. Track your progress using our free progress tracker to identify patterns in your weight and habits, which helps inform decisions about stopping 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.
Will I regain weight after stopping Mounjaro?
Weight regain is common after stopping Mounjaro without continued lifestyle changes. Clinical data shows people often regain 30–50% of lost weight within a year if they return to previous eating habits. However, sustained dietary changes and regular activity significantly reduce regain risk. Your GP can support you with ongoing monitoring and behaviour change strategies.
How long does it take to feel normal after stopping Mounjaro?
Most people notice reduced appetite suppression within 1–2 weeks of their final dose. However, adjusting mentally and emotionally to managing hunger without medication can take longer — typically 4–8 weeks. Nausea and digestive side effects usually resolve within 2–4 weeks. This transition period is normal; your GP or a dietitian can provide support.
Can I restart Mounjaro if I regain weight after stopping?
Yes, restarting is possible, but it requires a new clinical assessment and prescription. You cannot simply resume where you left off — you'll need to restart dose titration from 2.5 mg. Discuss restarting options with your GP or the NHS specialist service that prescribed it. Some people use intermittent courses rather than continuous treatment.
Should I use our GLP-1 weight loss calculator after stopping Mounjaro?
After stopping Mounjaro, the GLP-1 calculator is less relevant since you're no longer taking the medication. Instead, use our free progress tracker to log your actual weight changes and identify patterns in how your body responds post-treatment. Our BMI calculator helps monitor whether your weight sits in a healthy range (18.5–24.9, or lower thresholds for South Asian adults).
What NHS support is available after finishing Mounjaro?
NHS support depends on your local area and ICB commissioning. Many areas offer tier 2 or tier 3 weight management programmes that continue after medication stops, including dietitian support, behaviour change coaching, and ongoing monitoring. Ask your GP about availability. Weight loss clinics, community weight management programmes, and digital NHS apps are also available in most areas.
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.