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 Tips For Sustainable Results
Losing weight successfully requires a combination of approaches tailored to your lifestyle and health needs. Whether you're looking to shed a few kilograms or make a significant change, understanding the most effective weight management UK strategies can make all the difference. The NHS recommends losing weight at a rate of 0.5 to 1 kg per week for sustainable results. This guide covers practical tips, lifestyle changes, and prescription weight loss options available in the UK today.
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.
Evidence-Based Approaches to Weight Loss
The most effective weight loss strategies combine reduced-calorie eating with increased physical activity. A calorie deficit of around 500 kcal per day typically results in approximately 0.5 kg weight loss per week — this is the gold standard for sustainable loss without muscle damage. Use our free BMI calculator above to establish your current weight status and healthy weight range for your height.
- Dietary changes: Focus on whole foods, vegetables, lean proteins, and wholegrain carbohydrates. Processed foods and sugary drinks are calorie-dense and less filling.
- Physical activity: Aim for 150 minutes of moderate activity weekly (brisk walking, cycling) plus strength training twice weekly.
- Behaviour modification: Track eating patterns, manage stress, improve sleep quality, and stay hydrated — all significantly impact weight loss success.
- NHS Weight Loss Plan: Free, evidence-based 12-week programme available through NHS.uk with downloadable resources.
Even a 5% reduction in body weight can have meaningful health benefits including lower blood pressure, improved blood sugar control, and reduced joint strain.
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 in the UK
For adults who need additional support, prescription weight loss medications are now available through NHS specialist services and private prescribing in the UK. These include GLP-1 medications such as Wegovy (semaglutide) and Mounjaro (tirzepatide), which may help reduce appetite and support feeling fuller after meals. Clinical trials showed these medications help participants lose an average of 15–21% of body weight when combined with lifestyle changes — though individual results vary significantly.
Eligibility 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. All prescription weight loss medication requires a clinical assessment and must be prescribed by a registered healthcare professional. Try our free GLP-1 weight loss calculator to explore potential outcomes at different treatment levels.
- 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 safest rate of weight loss?
The NHS recommends losing 0.5 to 1 kg (1 to 2 lbs) per week. This sustainable pace preserves muscle mass, is easier to maintain long-term, and reduces health risks associated with gradual weight management. Very gradual weight management should only be pursued under medical supervision.
Can I lose weight through diet alone without exercise?
Yes, weight loss is primarily driven by calorie deficit — you can lose weight through diet alone. However, combining reduced calories with physical activity produces better results for health markers (blood pressure, cholesterol, fitness) and helps preserve muscle mass during weight loss.
How do GLP-1 weight loss injections work?
GLP-1 medications like Wegovy activate natural hormone pathways that regulate appetite and blood sugar. They may reduce food cravings, help you feel fuller after smaller meals, and slow gastric emptying. They're prescription-only and work best alongside reduced-calorie diet and increased physical activity.
Is prescription weight loss medication available on the NHS?
Yes. Tirzepatide (Mounjaro) is now approved for NHS use through specialist tier 3 weight management services. Access varies by region and may involve waiting lists. Private access is also available through GPhC-registered online pharmacies following clinical assessment.
What if I've tried diet and exercise but haven't lost weight?
Discuss with your GP — weight loss resistance can result from medical conditions (thyroid, PCOS, medication side effects), metabolic factors, or unrealistic timelines. Your GP can investigate underlying causes and discuss whether prescription weight loss treatment may help you, based on your individual circumstances.
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.