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
Understanding NICE Protocol and UK Weight Management Guidelines
NICE protocol refers to the guidance and recommendations issued by the National Institute for Health and Care Excellence — the UK's independent authority for health and social care standards. NICE produces evidence-based guidance on weight management, obesity, and healthy living that directly shapes NHS policy and clinical practice across England, Wales, Scotland, and Northern Ireland. This guidance helps healthcare professionals and patients make informed health decisions based on the latest clinical evidence.
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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 NICE Guidance Covers for Weight Management
NICE produces comprehensive guidance on obesity and weight management that influences how GPs and specialists approach patient care across the UK. Key NICE protocols for weight management include recommendations for healthy BMI ranges, dietary approaches, physical activity guidelines, and when prescription medications like GLP-1 injections (Mounjaro and Wegovy) should be considered.
- NICE recommends a healthy BMI range of 18.5 to 24.9 for most UK adults
- For South Asian, Chinese, Black African, and Black Caribbean adults, NICE aligns with NHS guidance recommending lower thresholds of 18.5 to 22.9
- NICE guidance emphasises that weight loss should be 0.5 to 1 kg per week for sustainable results
- NICE has approved tirzepatide (Mounjaro) for weight management within NHS specialist tier 3 and 4 services
- NICE assessment considers both BMI and weight-related health conditions like type 2 diabetes and hypertension
All NHS weight management services follow NICE protocols to ensure consistent, evidence-based care regardless of which part of the UK you live in.
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 NICE-Aligned Weight Management in the UK
If you're concerned about your weight or have been advised by your GP to lose weight, NICE guidance supports a stepped approach. Start by speaking to your GP about your health and lifestyle — they can assess your individual circumstances against NICE protocols and determine whether you'd benefit from structured weight management support, dietary advice, or prescription medication.
Many UK adults use our free BMI calculator to understand where they stand against NICE-aligned NHS healthy weight standards. Your GP can then guide you through tier 1 (self-help and community programmes), tier 2 (primary care-based support), or refer you to tier 3/4 specialist services if appropriate. NICE ensures that weight management guidance is tailored to your ethnicity, age, and existing health conditions.
- 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 is NICE protocol in UK health?
NICE (National Institute for Health and Care Excellence) is an independent UK authority that produces evidence-based guidance on health and social care. NICE protocols are the recommendations that shape NHS policy and clinical practice. For weight management, NICE guidance sets healthy BMI thresholds, recommends treatment pathways, and determines when prescription weight loss medications should be considered.
What does NICE say about healthy weight in the UK?
NICE aligns with NHS guidance recommending a healthy BMI of 18.5 to 24.9 for most UK adults. For South Asian, Chinese, Black African, and Black Caribbean adults, NICE recommends a lower threshold of 18.5 to 22.9 due to higher health risks at the same BMI. NICE also emphasises sustainable weight loss of 0.5 to 1 kg per week.
How does NICE guidance affect NHS weight management services?
All NHS weight management services across England, Wales, Scotland, and Northern Ireland follow NICE protocols. This ensures consistent, evidence-based care regardless of where you live. NICE guidance covers dietary approaches, physical activity targets, when to refer to specialists, and which prescription medications are approved for weight management within the NHS.
Can I access weight loss medication through NICE-approved NHS services?
Yes. NICE has approved prescription weight loss medications including tirzepatide (Mounjaro) for use within NHS specialist tier 3 and 4 weight management services. However, access is through referral from your GP to a specialist service in your area. Waiting times and availability vary significantly by region.
Does NICE protocol apply differently to people from different ethnic backgrounds?
Yes. NICE and NHS guidance recognises that people of South Asian, Chinese, Black African, and Black Caribbean heritage face higher health risks at lower BMI levels. NICE recommends lower BMI thresholds (18.5 to 22.9 instead of 18.5 to 24.9) for these groups. Your GP should assess you using ethnicity-appropriate thresholds.
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.