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
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How the NHS Can Help With Weight Loss
If you're struggling with your weight, the NHS offers a structured pathway to help. From free digital tools and community programmes to specialist medication like GLP-1 injections, support is available at different levels depending on your needs and circumstances. This guide explains what the NHS can offer and how to access weight management help across the UK.
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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.
The NHS Four-Tier Weight Management Pathway
The NHS provides weight loss support through a four-tier system designed to meet different needs:
- Tier 1: Self-help and community support. This includes the NHS Weight Loss Plan (a free 12-week digital programme), local weight management groups, and apps. You can access this without a GP referral.
- Tier 2: Primary care-based interventions. Your GP can refer you to structured behaviour change programmes, often delivered locally by community services. These typically focus on diet, physical activity, and lifestyle change.
- Tier 3: Specialist multidisciplinary weight management services. This is where prescription weight loss medications are considered, including GLP-1 injections like semaglutide (Wegovy) and tirzepatide (Mounjaro). You need a GP referral to access this level.
- Tier 4: Bariatric (weight loss) surgery. Reserved for people with severe obesity and significant health complications. Requires assessment through a specialist centre.
Most people start at Tier 1 or 2. Your GP can advise which tier is appropriate for your situation.
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.
Prescription Weight Loss Medication on the NHS
The NHS now recognises GLP-1 receptor agonist medications as part of weight management treatment. Tirzepatide (Mounjaro) and semaglutide (Wegovy) are both licensed for weight management in UK adults and may be prescribed through NHS Tier 3 specialist services.
You may be eligible if you have a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes, high blood pressure, or sleep apnoea. However, NHS access varies significantly by region — some areas have very long waiting lists. Your GP can discuss whether you meet the criteria and refer you to your local specialist weight management service. Use our free BMI calculator above to check your current BMI and understand where you sit on the NHS eligibility scale.
Accessing NHS weight loss medication can involve significant waiting times in many areas. If you meet the eligibility criteria and want faster access, prescription weight loss treatment is also available through private online prescribing services with UK-licensed prescribers, following a clinical assessment. However, the NHS remains a free option if you're willing to navigate referral and waiting lists. Track your weight loss progress using our free progress tracker to monitor changes as you pursue whatever pathway you choose.
- 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.
How do I get NHS help with weight loss?
Start by talking to your GP. They can advise which tier of the NHS pathway is appropriate for you, refer you to local services, or discuss whether prescription medication is suitable. You can also access Tier 1 support (like the NHS Weight Loss Plan) without a GP referral by visiting the NHS Every Mind Matters website or searching for local community weight management groups.
What is the NHS Weight Loss Plan?
The NHS Weight Loss Plan is a free, 12-week digital programme available to all UK adults. It provides weekly videos, tips on healthy eating and physical activity, and behaviour change support. It's delivered through the NHS Every Mind Matters platform and can be accessed online without a GP referral. It's a good first step if you're looking to lose weight.
Can I get GLP-1 weight loss injections on the NHS?
Yes, GLP-1 medications like Wegovy (semaglutide) and Mounjaro (tirzepatide) are now available through NHS specialist weight management services. However, you need a GP referral and must meet eligibility criteria (BMI 30+, or 27+ with weight-related health conditions). Availability and waiting times vary significantly by region — your GP can explain what's available locally.
What is a healthy rate of weight loss according to the NHS?
The NHS recommends losing weight at a rate of 0.5 to 1 kg (1 to 2 lbs) per week. This sustainable pace reduces muscle loss and helps establish long-term healthy habits. Faster weight loss is possible with medical support but should only be pursued under professional supervision.
Will my GP prescribe weight loss medication?
Your GP can discuss weight loss medication options, but prescription medications are typically initiated and managed by specialist weight management services (Tier 3) rather than general practice. Your GP will refer you if they believe medication is appropriate for you. The decision depends on your BMI, health conditions, and local service availability.
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.