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
If I'm Overweight — What UK Health Guidance Says
If you're concerned about being overweight, the NHS provides clear guidance to help you understand your health and explore manageable options. Being overweight is common in the UK — around 63% of UK adults fall into the overweight or obese category — and there are evidence-based approaches that can help. This UK health guide covers healthy weight ranges, how to use BMI to assess your health, and practical weight management strategies. Understanding where you stand and what options are available is the first step toward making informed health decisions.
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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.
Understanding Healthy Weight in the UK
NHS guidance defines healthy weight using BMI (Body Mass Index), calculated from your height and weight. According to NHS health advice, a healthy BMI range is 18.5 to 24.9. If your BMI falls between 25 and 29.9, you're classified as overweight; 30 and above is obese.
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recommends lower thresholds — a healthy BMI starts at 18.5 and ends at 22.9, because these groups face higher health risks at lower weights.
- Use our free BMI calculator to find your current BMI
- Calculate your healthy weight range using our weight converter
- Remember that BMI doesn't account for muscle mass — it's a screening tool, not a complete picture
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.
Steps You Can Take Now
If you're overweight, the NHS recommends starting with small, sustainable changes rather than drastic measures. A healthy weight loss rate is 0.5 to 1 kg per week, achieved through a calorie deficit of around 500 kcal daily alongside increased physical activity.
- Speak to your GP — they can assess your individual health and discuss weight management options
- Try the NHS Weight Loss Plan, a free 12-week digital programme
- Consider NHS tier 3 specialist weight management services if you need additional support
- Track your progress using our free progress tracker to stay motivated
Even losing 5–10% of your body weight can improve blood pressure, blood sugar control, and overall health.
- 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.
What counts as overweight according to NHS guidance?
The NHS classifies adults with a BMI between 25.0 and 29.9 as overweight. BMI is calculated by dividing your weight in kg by your height in metres squared. Use our free BMI calculator for instant results. For people of South Asian or Black African heritage, overweight starts at a BMI of 23.
How much weight should I aim to lose per week?
The NHS recommends losing 0.5 to 1 kg per week for sustainable, healthy weight loss. This typically requires a calorie deficit of around 500 kcal daily. Faster weight loss can lead to muscle loss and is harder to maintain long-term.
Should I see my GP if I'm overweight?
Yes. Your GP can assess your individual health, check for weight-related conditions like type 2 diabetes or high blood pressure, and discuss weight management options including NHS Weight Loss Plans and specialist services. This ensures your approach is safe for your specific health profile.
What weight loss options are available through the NHS in the UK?
The NHS offers tiered support: self-help digital programmes (tier 1), GP-led behaviour change programmes (tier 2), specialist multidisciplinary weight management services (tier 3), and bariatric surgery for severe obesity (tier 4). Ask your GP about availability in your area.
Can prescription weight loss medications help if I'm overweight?
Prescription medications like Mounjaro and Wegovy may be available through NHS specialist services or private prescription if you meet eligibility criteria (typically BMI 30+, or 27+ with weight-related conditions). These work alongside diet and exercise, not instead of them. Your GP or a licensed prescriber can assess suitability.
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.