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 Programme — Your Guide to UK Options
A weight loss programme is a structured approach to losing weight safely and sustainably. In the UK, weight loss programmes range from self-help tools and NHS-funded initiatives to prescription weight loss medication and specialist services. The NHS recommends a weight loss of 0.5 to 1 kg per week alongside dietary changes and increased physical activity. Understanding your options—from tier 1 community programmes to prescription GLP-1 injections—helps you choose an approach that fits your health needs and circumstances.
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 UK Weight Loss Programmes Work
The NHS operates a four-tier weight management pathway designed to meet people at different stages of their weight loss journey. Tier 1 provides self-help and digital tools—like our free BMI calculator and weight management resources—alongside community weight loss groups. Tier 2 involves structured programmes run by GPs, focusing on behaviour change and lifestyle adjustments. Tier 3 is specialist multidisciplinary weight management services available through NHS referral, where prescription weight loss medication may be considered for eligible adults. Tier 4 covers bariatric surgery for severe obesity with significant health complications.
To access NHS weight loss support, speak to your GP about your weight management goals. Eligibility for prescription weight loss medication typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Evidence-based dietary approaches—including the Mediterranean diet and sustained calorie deficit methods—are recommended at every tier.
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 Options Available in the UK
For adults who meet clinical criteria, prescription weight loss injections are now available in the UK. Medications like Mounjaro (tirzepatide) and Wegovy (semaglutide) are GLP-1 receptor agonists—prescription-only medicines that work by reducing appetite and helping you feel fuller after meals. Clinical trials show these medications may help users lose an average of 15–21% of body weight when combined with dietary changes and physical activity. Access is available through NHS specialist tier 3 services (with potential waiting lists) or through private prescription following an online clinical assessment.
Whichever weight loss programme you choose, tracking your progress is essential. Our free progress tracker helps you log weight changes, monitor your BMI over time, and visualise your journey. Combined with our GLP-1 weight loss calculator—which projects potential weight loss at different medication doses—you can make informed decisions about your weight management strategy.
- 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 programmes?
NHS weight loss programmes are free but may involve waiting lists and regional variation in access. Private programmes (including prescription weight loss medication) are available immediately through private consultations but cost £100–£350+ per month. Both can be effective; the choice depends on your timeline, budget, and preference for specialist oversight.
How much weight can I expect to lose on a weight loss programme?
This varies significantly by individual. Safe, sustainable loss is 0.5–1 kg per week. Clinical trials of prescription weight loss medication show average losses of 15–21% of body weight over 12–18 months alongside lifestyle changes. Use our GLP-1 weight loss calculator to estimate potential outcomes—individual results vary.
Do I need a referral from my GP to access a weight loss programme?
For NHS tier 1 and tier 2 services, you can often self-refer or ask your GP. For tier 3 specialist services (where prescription medication is considered), a GP referral is typically required. Private weight loss programmes do not require NHS referral and can be accessed directly.
What health conditions make someone eligible for prescription weight loss medication?
Adults with a BMI of 30+ are eligible. Those with a BMI of 27–29.9 may qualify if they have weight-related conditions: type 2 diabetes, prediabetes, high blood pressure, high cholesterol, or obstructive sleep apnoea. Your prescriber assesses eligibility based on your individual health profile.
Is a weight loss programme suitable for everyone?
Most adults can benefit from structured weight loss support. However, prescription medications are not suitable during pregnancy, whilst breastfeeding, or for people with certain medical conditions. Your GP or prescriber will assess whether a specific programme is right for you. Use our free BMI calculator to check your personal BMI as a starting point.
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.