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
Walking vs Running for Weight Loss — Which Is Better?
Both walking and running can support weight loss when combined with a calorie deficit, but they differ in intensity, sustainability, and calorie burn. Running typically burns more calories per session than walking, but walking is more sustainable for many people and easier to maintain long-term. The best exercise for weight loss is the one you'll actually do consistently. However, exercise alone is rarely enough for significant weight loss — dietary changes and, for eligible adults, prescription weight loss medication can make a meaningful difference to your progress.
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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.
Exercise Alone vs Prescription Weight Management
Walking and running are both valuable for weight management in the UK, but they work best alongside dietary changes. Running burns approximately 600–900 calories per hour depending on speed and body weight, whilst walking burns 200–400 calories per hour. However, the NHS emphasises that sustainable weight loss requires a calorie deficit, which is most effectively achieved through a combination of physical activity and reduced calorie intake.
For adults who are struggling to lose weight through exercise and diet alone, prescription weight loss medication is now available in the UK. GLP-1 medications like Mounjaro and Wegovy are licensed for weight management and work by helping regulate appetite and food cravings. Clinical evidence shows these medications support weight loss of 15–21% on average when combined with lifestyle changes — far more significant than exercise or diet changes alone. You can estimate your potential weight loss with our GLP-1 weight loss calculator to understand what might be achievable with medication support.
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.
UK Eligibility and How to Access Weight Loss Support
In the UK, adults with a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea) may be eligible for prescription weight loss treatment. Eligibility is assessed on an individual basis by a GP or licensed prescriber.
You can check your personal BMI instantly using our free BMI calculator. If you're interested in exploring whether prescription weight loss medication might help you, speak to your GP about referral to specialist weight management services, or access private online prescribing through a UK-licensed prescriber following a clinical assessment. Your GP can also advise on local NHS weight loss programmes, which often include dietary support and exercise guidance tailored to your individual needs.
- 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.
Does running burn more calories than walking?
Yes — running typically burns 600–900 calories per hour compared to 200–400 for walking, depending on intensity and body weight. However, walking is more sustainable for many people and less injury-prone, making it easier to maintain long-term for consistent weight loss.
Can I lose weight through running alone without changing my diet?
Weight loss requires a calorie deficit, which is difficult to achieve through exercise alone. The NHS recommends combining physical activity with dietary changes. For significant weight loss, many people benefit from combining exercise and diet with prescription weight loss medication if eligible.
What is the difference between Mounjaro and Wegovy for weight loss?
Both are prescription-only GLP-1 medications licensed for weight management in the UK. Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist showing average weight loss of 15–21%, whilst Wegovy (semaglutide) is a GLP-1 agonist alone with average weight loss around 15%. Individual results vary, and a prescriber will assess which is suitable for you.
How do I know if I'm eligible for prescription weight loss medication in the UK?
Adults with BMI 30+ or BMI 27–29.9 with weight-related health conditions may be eligible. Eligibility is assessed individually. Use our free BMI calculator to check your BMI, then speak to your GP about specialist weight management services or private prescribing options.
Is prescription weight loss medication available on the NHS in the UK?
Yes — Mounjaro and Wegovy are available through NHS specialist weight management services (tier 3), though access varies by region and waiting lists can be lengthy. Private access through GPhC-registered online prescribers is also available, typically ranging from £129–£320 per month depending on dose.
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.