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
NHS Weight Loss Services — How to Access Support in the UK
The NHS offers a structured approach to weight management through its four-tier system, from self-help tools to specialist prescription medication and bariatric surgery. Access to NHS weight loss services depends on your BMI, health conditions, and local availability. Understanding how these services work can help you find the right support for your weight loss journey in the UK.
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.
How the NHS Weight Loss Pathway Works
The NHS uses a four-tier weight management pathway to support adults with excess weight. Tier 1 focuses on self-help and digital tools — this is where services like MyWeightCheck's free BMI calculator and weight converter help you understand your starting point. Tier 2 provides primary care-based support through your GP, including behaviour change programmes like the NHS Weight Loss Plan and referral to community weight management services. Tier 3 offers specialist multidisciplinary support — this is where prescription weight loss medication, including GLP-1 weight loss injections, may be considered. Tier 4 is reserved for severe obesity with significant health complications, where bariatric (weight loss) surgery may be an option. Most people start at Tier 1 or 2, with progression based on individual health needs and response to initial interventions.
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 Through the NHS
Access to prescription weight loss medication through the NHS typically happens at Tier 3 services following specialist assessment. NICE has approved tirzepatide (Mounjaro) and semaglutide (Wegovy) for weight management in NHS settings. However, NHS availability varies significantly by region — some areas have established specialist services with shorter waiting times, whilst others have lengthy waiting lists or limited capacity. Your GP can refer you to your local tier 3 weight management service, but eligibility and waiting times depend on your BMI, health conditions, and regional NHS commissioning decisions. Use our free GLP-1 weight loss calculator to understand how prescription medication might support your individual goals.
- 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 access NHS weight loss services?
Contact your GP and ask for a referral to your local weight management service. Your GP will assess your BMI, health conditions, and eligibility. Tier 1 (self-help) is available to everyone; higher tiers require progression through the pathway based on individual need and response to earlier interventions.
What is the difference between Tier 2 and Tier 3 weight loss services?
Tier 2 is primary care-based, offered by your GP or local community services, focusing on behaviour change and lifestyle support. Tier 3 is specialist services delivered by multidisciplinary teams (dietitians, psychologists, doctors) where prescription medication and more intensive support are available.
Can I get Wegovy or Mounjaro on the NHS?
Potentially, yes — both are NICE-approved for NHS use. However, access is through specialist Tier 3 services and varies significantly by region. Some areas have waiting lists of many months. Ask your GP about specialist services in your local NHS area (your Integrated Care Board).
What happens if I'm not eligible for NHS weight loss services?
Private options are available. You can access prescription weight loss medication through private online prescribing services following a clinical assessment. Costs vary by medication and dose but typically range from £129–£320 per month depending on your chosen treatment.
Will the NHS cover the cost of weight loss medication?
If prescribed through NHS Tier 3 services, the medication is free on the NHS (you only pay standard prescription charges if eligible). Private prescribing requires payment. Cost varies by medication, dose, and provider — ask your prescriber for pricing details before starting treatment.
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.