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
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Best Workout For Quick Weight Loss
Exercise is crucial for weight loss, but the reality is that workouts alone produce gradual results. If you're looking for quicker weight management in the UK, prescription medications like Mounjaro and Wegovy, combined with exercise and diet, can help accelerate progress. This guide explains how different workout types support weight loss, and how prescription weight loss options can enhance your results when eligible.
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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.
Exercise, Diet, and Prescription Weight Loss — A Combined Approach
The most effective approach to quick weight loss combines three elements: calorie deficit through diet, regular physical activity, and where appropriate, prescription weight management medication.
The NHS recommends losing weight at a rate of 0.5–1 kg per week for sustainable results. While exercise burns calories and builds muscle, diet creates the calorie deficit needed for actual weight loss. For eligible adults in the UK, prescription weight loss medications can accelerate this process:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist. In clinical trials, participants lost an average of 15–21% of body weight alongside reduced-calorie diet and exercise.
- Wegovy (semaglutide) — A GLP-1 receptor agonist helping reduce appetite and support feeling fuller. Average weight loss in trials was approximately 15% of body weight.
- Saxenda (liraglutide) — A daily GLP-1 injection, with similar mechanisms to Wegovy.
These medications work by reducing appetite, supporting healthier food choices, and improving satiety — making it easier to maintain a calorie deficit. They are prescription-only and require a clinical assessment from a GP or licensed prescriber to determine eligibility.
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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.
Who Is Eligible For Prescription Weight Loss In The UK?
To access prescription weight loss medication in the UK, you must meet NHS eligibility criteria:
- BMI of 30 or above, or
- BMI of 27–29.9 with at least one weight-related health condition (type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, sleep apnoea, or cardiovascular disease history)
- For South Asian, Chinese, Black African, or Black Caribbean adults, thresholds may be lower (BMI 27.5 or above)
Use our free BMI calculator to check your personal BMI instantly. If you meet the criteria, discuss prescription weight loss options with your GP. The NHS increasingly funds these medications through specialist weight management services, though private online prescribing is also available if you prefer faster access.
- 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 best workout for gradual weight management?
No single workout is "best" — consistency matters more than intensity. Combine cardio (walking, running, cycling), strength training (builds muscle, speeds metabolism), and flexibility work. Exercise works fastest when paired with a calorie deficit through diet. For qualifying adults, prescription weight loss medication can amplify results without requiring extreme exercise.
Can I lose weight quickly with exercise alone?
Exercise alone is slow. To lose 0.5 kg per week through exercise, you'd need to burn approximately 500 extra calories daily — difficult without dietary changes. The NHS recommends combining reduced-calorie diet with 150 minutes of moderate activity weekly for optimal results.
How do GLP-1 medications support weight loss UK?
Prescription GLP-1 medications like Mounjaro and Wegovy reduce appetite, increase satiety, and slow stomach emptying. This makes it easier to eat less and maintain a calorie deficit. They're most effective alongside exercise and healthy eating — not replacements for lifestyle change.
Am I eligible for prescription weight loss in the UK?
Check your BMI using our free BMI calculator. If your BMI is 30 or above, or 27–29.9 with weight-related health conditions, you may be eligible. Contact your GP to discuss NHS access or explore private prescribing options. Individual eligibility is determined by a healthcare professional.
How quickly will I see results with Mounjaro or Wegovy?
Weight loss typically begins within 2–4 weeks. Most significant results occur after 12–16 weeks as doses are gradually increased. Results vary between individuals. Clinical trials showed average weight loss of 15–21% (Mounjaro) or 15% (Wegovy) over approximately 68–72 weeks alongside diet and exercise.
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.