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 Does "Weighted Body" Mean for Your Health?
A "weighted body" typically refers to carrying excess body weight above what's considered healthy for your height and age. This UK health guide explains what excess weight means for your health, how to assess it, and what weight management options are available through NHS guidance and evidence-based approaches. Understanding your current weight in relation to your height is the first step toward better health outcomes.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Body Weight and Health Risk
Excess body weight increases the risk of several serious health conditions, including type 2 diabetes, high blood pressure, heart disease, and certain cancers. The NHS uses BMI (body mass index) as a screening tool to assess whether your weight is in a healthy range for your height. A healthy BMI is between 18.5 and 24.9 for most UK adults, though lower thresholds apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage.
Even modest weight loss can make a real difference: losing just 5–10% of your body weight can reduce blood pressure, improve blood sugar control, and lower cholesterol. Use our free BMI calculator above to check your personal BMI instantly, and our weight converter to see your weight in stone, pounds, and kilograms side by side.
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.
Weight Management Options Available in the UK
The NHS supports weight management through multiple tiers, from self-help resources and digital tools to specialist services and prescription medications. For adults with a BMI of 30 or above, or 25–29.9 with weight-related health conditions, prescription weight loss treatments may be appropriate following clinical assessment. These include GLP-1 receptor agonist medications such as semaglutide (Wegovy) or tirzepatide (Mounjaro), which may help reduce appetite and support sustainable weight loss alongside dietary changes and physical activity.
Your GP can refer you to specialist weight management services, or you can access private prescribing options. Try our GLP-1 weight loss calculator to explore projected outcomes at different medication doses.
- 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's the difference between "weighted body" and being overweight?
A weighted body simply means carrying more weight than ideal for your height. The NHS classifies this as "overweight" (BMI 25–29.9) or "obese" (BMI 30+). Both terms are clinical descriptors used to assess health risk, not judgments about appearance or worth.
How do I know if my weight is healthy for my height?
Calculate your BMI using our free BMI calculator on this page—it takes your height and weight and shows you where you fall on the NHS scale. A healthy BMI is 18.5–24.9 for most UK adults. Lower thresholds apply for South Asian and other heritage groups. Your GP can also provide personalised guidance.
Can excess weight be managed without medication?
Yes. The NHS recommends lifestyle changes first: a balanced diet with a modest calorie deficit (around 500 kcal per day), regular physical activity, and behaviour change support. Many people achieve sustainable weight loss through these approaches alone. Medication is considered when lifestyle changes alone haven't been effective.
How fast is it safe to lose weight?
The NHS recommends losing weight at a rate of 0.5–1 kg (1–2 lbs) per week for sustainable, healthy weight loss. Faster loss is possible with medical support but carries increased risks. Use our free progress tracker to log your journey and monitor steady progress over time.
What weight loss medications are available on the NHS in the UK?
The NHS can prescribe tirzepatide (Mounjaro), semaglutide (Wegovy), and liraglutide (Saxenda) for weight management in eligible adults. Access is through specialist tier 3 weight management services. Clinical assessment determines suitability. Private prescribing is also available through licensed UK prescribers.
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.