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
Exercise Programme For Weight Loss And Toning
A structured exercise programme is one of the most effective ways to support weight loss and build muscle tone. However, for many people in the UK, combining regular physical activity with evidence-based weight management support—including prescription options—can accelerate results and improve overall health outcomes. This guide covers how exercise works for weight loss, and explores the prescription weight loss options available to eligible UK adults alongside a fitness routine.
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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.
UK-Licensed Prescription Weight Loss Options
If you're struggling to lose weight through exercise and diet alone, prescription weight loss medication may be available to you through the NHS or private prescribing in the UK. Three GLP-1 receptor agonist medications are currently licensed for weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 agonist administered once weekly. Clinical trials showed average weight loss of 15–21% of body weight when combined with lifestyle changes.
- Wegovy (semaglutide) — a GLP-1 agonist given once weekly, with average weight loss of approximately 15% in clinical trials.
- Saxenda (liraglutide) — a daily GLP-1 injection, with evidence supporting modest weight loss alongside exercise.
All are prescription-only medicines requiring clinical assessment. You may be eligible if your BMI is 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our GLP-1 weight loss calculator to explore potential weight loss projections 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.
Getting Started: NHS Vs Private Prescription
Access to prescription weight loss medication in the UK depends on your route:
- NHS route: Your GP can refer you to a specialist tier 3 weight management service, where eligibility is assessed and medication prescribed if appropriate. Waiting times and availability vary significantly by region.
- Private route: You can access prescription weight loss treatment through a GPhC-registered online prescriber without an NHS referral. A clinical assessment is required; if approved, medication is dispensed by a registered pharmacy.
Either way, prescription weight loss medication works best when combined with a structured exercise programme, a balanced reduced-calorie diet, and behavioural support. Speak to your GP about whether this approach is right for you and check your eligibility for NHS support in your area.
- 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.
Can I use exercise alone to lose weight without medication?
Yes, exercise combined with a calorie deficit can support weight loss. The NHS recommends 150 minutes of moderate activity weekly plus strength training. However, if you've found this difficult or progress has stalled, prescription medication alongside exercise may help. Your GP can advise what's right for you.
How much weight can I expect to lose with prescription weight loss medication?
Clinical trials show average weight loss of 15–21% of body weight over several months with Mounjaro or Wegovy, alongside exercise and diet changes. Individual results vary significantly. Use our weight loss calculator to estimate potential outcomes at different doses.
What is the NHS eligibility criteria for prescription weight loss treatment?
You may be eligible if your BMI is 30 or above, or 27 or above with a weight-related health condition. Your GP or a specialist weight management service will assess your individual circumstances and health history.
How long does prescription weight loss medication take to work?
Most people notice reduced appetite within the first 1–2 weeks. Measurable weight loss typically begins within 4 weeks, with ongoing loss over several months. Results are best when combined with consistent exercise and dietary changes.
Can I combine exercise with weight loss injections?
Yes—in fact, prescription weight loss medication works best alongside regular exercise and a reduced-calorie diet. The medication helps manage appetite while you build the habit of regular physical activity and healthy eating.
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.