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
Can You Lose Weight Easily? What the Evidence Actually Shows
Weight loss doesn't happen easily for most people — but there are evidence-based strategies that make it more manageable. The NHS confirms that sustainable weight management combines dietary changes, physical activity, and sometimes prescription support. This guide explains what realistic weight loss looks like, how your BMI fits into the picture, and the options available to you in the UK, including prescription medications like GLP-1 injections that may help support your efforts alongside lifestyle changes.
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.
What Does "Easy" Weight Loss Really Mean?
The idea of "easy" weight loss is often misleading. Most people find weight management challenging because it requires sustained behaviour change. However, evidence shows that certain approaches work better than others. The NHS recommends losing 0.5 to 1 kg per week for sustainable results — this typically requires a calorie deficit of around 500 kcal daily. While this might seem gradual, it prevents muscle loss and is more likely to be maintained long-term.
Prescription weight loss medications like Wegovy (semaglutide) and Mounjaro (tirzepatide) can support weight management when combined with diet and exercise. In clinical trials, these GLP-1 medications helped participants lose an average of 15–21% of body weight over several months — though individual results vary significantly. They work by helping regulate appetite and supporting a reduced-calorie diet, not by doing the work for you. Calculate your current BMI using our free BMI calculator above to understand where you stand, then explore whether prescription support might be appropriate 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.
What Makes Weight Loss Easier?
Several factors make weight loss more achievable:
- Structured support — whether through NHS weight management services, dietitian guidance, or online programmes
- Realistic goals — aiming for 5–clinically studied weight loss has proven health benefits without requiring extreme restriction
- Combined approach — diet and physical activity together are more effective than either alone
- Medical support — prescription weight loss medication may help some people achieve results when prescribed following clinical assessment
Our free progress tracker helps you log your weight journey and visualise progress over time. Even small, consistent losses compound into meaningful health improvements. If you're exploring prescription weight loss options like GLP-1 medication, our weight loss calculator can help estimate potential results at different doses — though always discuss eligibility with your GP or a licensed prescriber first.
- 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.
Is weight loss easily possible without medication?
Yes, weight loss is possible through diet and exercise alone, but it requires consistent calorie deficit and lifestyle change. Many people find it challenging without support. The NHS offers free weight management programmes and your GP can refer you to specialist services. Results vary based on individual factors including metabolism, medical history, and adherence.
Can GLP-1 injections like Wegovy make weight loss easier?
Wegovy (semaglutide) is a prescription medication that may help support weight loss by reducing appetite and supporting a lower-calorie diet. Clinical trials showed average weight loss of 15% body weight — but individual results vary. Medication works alongside, not instead of, dietary and lifestyle changes. You must be assessed by a prescriber to determine eligibility.
What's the difference between Wegovy and Ozempic for weight loss?
Both contain semaglutide, but Wegovy is specifically licensed for weight management in the UK, whilst Ozempic is approved for type 2 diabetes. Ozempic should not be used off-label for weight loss. Wegovy is the correct licensed option if your prescriber recommends semaglutide for weight management.
How do I access weight loss medication through the NHS?
Prescription weight loss treatment is available through NHS specialist tier 3 weight management services. Ask your GP for a referral. Availability varies by region and waiting times can be lengthy. Private prescribing is also available through GPhC-registered online pharmacies following clinical assessment with a UK-licensed prescriber.
What does a healthy weight loss rate look like?
The NHS recommends 0.5–1 kg per week for sustainable weight loss. This typically requires a 500 kcal daily deficit through diet and exercise. Faster loss risks muscle loss and is difficult to maintain. Use our free weight converter to track progress between stone, lbs, and kg, and our progress tracker to monitor weekly changes.
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.