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 Help — What Support Is Available?
The NHS offers structured weight management support across four tiers, from self-help tools to specialist prescription medication. If you're looking for weight loss help in the UK, your GP is the starting point. The NHS can provide lifestyle support, dietary guidance, and in some cases, prescription weight loss medication — though access varies by region. Understanding your options helps you find the right support for your situation.
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 Supports Weight Management
The NHS uses a four-tier approach to weight management support. Tier 1 includes self-help, digital tools like the NHS Weight Loss Plan, and community-based programmes — ideal if you're just starting your weight loss journey. Tier 2 involves your GP and practice nurse, offering behaviour change support and monitoring. Tier 3 is specialist multidisciplinary weight management services, where you may access prescription medications like GLP-1 injections. Tier 4 is bariatric (weight loss) surgery for severe obesity with significant health complications. Your GP will assess which tier is appropriate for you based on your BMI, health conditions, and previous weight loss attempts. Access to medication and specialist services varies significantly by region — some areas have shorter waiting lists than others. Use our free BMI calculator above to determine your current BMI category, which helps your GP decide the best tier 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 has approved prescription weight loss medication for eligible adults through specialist services. The most commonly available options are GLP-1 injections, which help reduce appetite and support weight management. You typically need a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure, to be considered. Access is through NHS tier 3 specialist weight management services rather than your standard GP practice. Waiting times can be substantial in many areas — sometimes several months. If you want to explore medication options more quickly, private online prescribing is also available in the UK following clinical assessment. Our GLP-1 weight loss calculator can help you understand potential outcomes alongside your NHS conversations.
- 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 support?
Contact your GP first. They'll assess your weight, health, and previous weight loss attempts, then refer you to the appropriate tier of NHS support. For specialist services and medication, you'll be referred to your local tier 3 weight management service.
How long are NHS weight loss waiting lists?
Waiting times vary significantly by region and NHS trust. Some areas have waiting lists of several months or longer. Private weight management services are available if you prefer faster access to medication.
What prescription weight loss medications does the NHS offer?
The NHS primarily uses GLP-1 receptor agonist injections through specialist services. Eligibility and availability depend on your BMI, health conditions, and local NHS provision.
Can I get prescription weight loss injections like Mounjaro or Wegovy on the NHS?
These medications may be available through NHS specialist weight management services if you meet eligibility criteria. However, access is limited and varies by region. Your GP can assess your eligibility and refer you if appropriate.
What if I can't get NHS weight loss medication quickly?
Private online prescribing is available in the UK through GPhC-registered pharmacies following a clinical assessment. Private options are faster but involve costs. Discuss both NHS and private options with your GP to find what works best for you.
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.