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
How to Boost Your Weight Loss: Evidence-Based UK Guide
Boosting your weight loss means combining proven strategies that work with your lifestyle and health needs. Whether you're managing your weight through diet and exercise, considering prescription weight loss medication, or accessing NHS support, understanding what actually works is essential. This guide covers the most effective approaches for UK adults, aligned with NHS guidance and clinical evidence. Your starting point matters — calculating your BMI and current weight in stone or kg helps you track progress accurately and set realistic goals.
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.
Key Strategies to Boost Weight Loss Sustainably
Create a sustainable calorie deficit: The NHS recommends losing weight at a rate of 0.5 to 1 kg per week for long-term success. This typically requires a daily calorie deficit of around 500 kcal, achieved through a combination of dietary changes and increased physical activity. Crash dieting or extreme restriction leads to muscle loss and rebound weight gain.
- Aim for whole foods, lean proteins, and plenty of vegetables
- Track your intake using a food diary or app
- Combine with regular activity — even 30 minutes of walking daily helps
Consider prescription weight loss medication: For those with a BMI of 30 or above (or 27+ with weight-related health conditions), GLP-1 weight loss medication may support your efforts. Prescription weight loss injections like Mounjaro (tirzepatide) and Wegovy (semaglutide) work by helping regulate appetite and promote feeling fuller. Clinical trials showed these may help achieve average weight loss of 15–21% body weight when combined with lifestyle changes. Use our free GLP-1 weight loss calculator to estimate potential results at different doses.
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.
NHS Support and Prescription Options Available in the UK
The NHS offers a structured weight management pathway. Tier 1 includes self-help tools and community programmes, Tier 2 provides GP-led behaviour change support, and Tier 3 offers specialist multidisciplinary weight management services where prescription weight loss medication may be prescribed. Access varies significantly by region — ask your GP about local tier 3 services or NHS weight loss programmes available in your area.
Private prescribing is also available: GLP-1 medications can be prescribed through private online services following a clinical assessment, offering faster access if you don't meet NHS referral criteria or face long waiting lists. Either route requires a licensed UK prescriber to assess whether medication is appropriate for your health.
Track your progress with our free progress tracker to visualise weight loss over time and stay motivated.
- 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's the realistic amount of weight I can lose per week?
The NHS recommends 0.5 to 1 kg per week for sustainable weight loss. This pace allows your body to adjust, preserves muscle mass, and creates habits that stick. Faster loss is possible with medical supervision but increases muscle loss risk and isn't necessary for long-term success.
Do I need to exercise to boost weight loss?
Physical activity significantly supports weight loss by increasing calorie burn, preserving muscle, and improving health markers. However, weight loss is primarily driven by a calorie deficit — you can lose weight through diet alone, but combining both creates better, faster results and improved fitness.
How do prescription weight loss injections work?
GLP-1 medications like Wegovy and Mounjaro (a GIP/GLP-1 agonist) help regulate appetite hormones and promote feeling fuller after smaller meals. Clinical trials showed average weight loss of 14–21% body weight with these medications. They work alongside — not instead of — dietary changes and physical activity.
Can I get GLP-1 weight loss medication on the NHS?
Yes, through NHS specialist tier 3 weight management services, though availability and waiting times vary significantly by region. Your GP can refer you if you meet eligibility criteria. Private prescribing is also available through UK-licensed online prescribers, often with faster access.
What's the difference between Mounjaro and Wegovy for weight loss?
Wegovy (semaglutide) is a GLP-1 agonist with maximum dose 2.4 mg weekly. Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist with maximum dose 15 mg weekly. Clinical trials suggest Mounjaro may achieve slightly higher average weight loss, but both are prescription-only and require individual clinical assessment.
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.