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
Weight Loss Medication Available on the NHS
Weight loss medication is available through the NHS for eligible UK adults, though access varies significantly by region. The NHS offers prescription weight management treatments through specialist tier 3 services, requiring referral from your GP. Eligibility depends on your BMI and weight-related health conditions. GLP-1 medications like Wegovy and Mounjaro are now approved for NHS use, though waiting lists and regional availability differ. Understanding how the NHS weight management pathway works can help you explore whether prescription medication is right for your situation.
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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.
NHS Weight Management Pathway and Eligibility
The NHS uses a four-tier weight management pathway. Tier 1 includes self-help resources and community programmes. Tier 2 involves primary care-based interventions like behaviour change support. Tier 3 is where prescription weight loss medication is typically initiated — this is a specialist multidisciplinary weight management service requiring GP referral. Tier 4 covers bariatric surgery for severe obesity with significant health complications.
To access NHS weight loss medication, you generally need a BMI of 30 or above, or 27–29.9 with weight-related health conditions. Eligible conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or history of cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply due to higher health risks. Use our free BMI calculator above to check your starting point. Access is through referral to your regional tier 3 service — your GP can provide this referral.
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.
GLP-1 Medications Now Available on the NHS
Tirzepatide (Mounjaro) and semaglutide (Wegovy) are now approved for NHS use following NICE approval. These are GLP-1 and GIP/GLP-1 receptor agonist medications that may help with weight management alongside reduced-calorie diet and increased physical activity. In clinical trials, these medications helped participants lose an average of 15–21% of body weight, though individual results vary significantly.
NHS access involves a specialist assessment at tier 3, which determines whether prescription medication is suitable for you. Regional variation is substantial — some areas have established services while others face long waiting lists. Our GLP-1 weight loss calculator can help you understand potential outcomes at different doses. Your GP can discuss tier 3 referral options and expected timelines in your area.
- 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 the difference between NHS and private weight loss medication access?
NHS access requires tier 3 specialist referral from your GP with potential waiting lists. Private access is through online clinical assessment with UK-licensed prescribers without NHS referral, available immediately but at personal cost. Both routes require prescription and clinical assessment.
How long does it take to get weight loss medication through the NHS?
Timelines vary significantly by region and service availability. Some areas offer appointments within weeks; others have waiting lists of months to over a year. Contact your GP for referral and ask about expected waiting times in your locality.
Can I use Ozempic for weight loss on the NHS?
Ozempic contains semaglutide but is licensed for type 2 diabetes management only, not weight loss. Wegovy is the NHS-approved weight management version of semaglutide. Using Ozempic for weight loss would be off-label and is not routinely available for this purpose.
What happens if I don't meet NHS eligibility criteria?
If you don't meet NHS criteria, you can explore private prescription routes through online clinical assessment. Lifestyle changes including calorie deficit, increased physical activity, and behaviour change remain effective. Discuss options with your GP.
Do I need to use the weight converter or BMI calculator to apply for NHS weight loss medication?
Your GP will assess your weight and BMI as part of the referral process. Using our free BMI calculator and weight converter can help you understand your baseline and track progress, but formal NHS assessment uses clinical measurements.
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.