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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How to Weight Loss With Exercise — UK Approach
Exercise is a key part of sustainable weight loss, but combining physical activity with dietary changes and, where appropriate, prescription medication gives the best results in the UK. The NHS recommends a balanced approach that includes both exercise and reduced calorie intake. For many people, especially those with a BMI over 30 or with weight-related health conditions, prescription weight management options are now available alongside exercise and lifestyle changes. This guide explains how exercise fits into a comprehensive weight loss strategy, and what medication options exist in the UK.
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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 Prescription Weight Loss Options Alongside Exercise
Three prescription medications are currently licensed in the UK for weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 injection, once weekly, up to 15mg. Clinical trials showed average weight loss of 15–21% body weight when combined with diet and exercise.
- Wegovy (semaglutide) — a GLP-1 injection, once weekly, up to 2.4mg. Evidence suggests average weight loss of around 15% body weight at maximum dose.
- Saxenda (liraglutide) — a GLP-1 injection, once daily, up to 3mg. Effective for weight management when combined with lifestyle changes.
All three are prescription-only medicines. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, hypertension, or cardiovascular disease. Individual results vary significantly. These medications work best alongside a reduced-calorie diet and increased physical activity — they are not replacements for exercise and healthy eating. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses if you think you may be eligible.
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 vs Private Access and Next Steps
NHS access: Prescription weight loss medication is available through NHS specialist tier 3 and tier 4 weight management services. You will typically need a GP referral and assessment by a specialist team. Availability and waiting times vary significantly by region — some ICBs have waiting lists of several months or longer.
Private access: If you do not want to wait for NHS services, licensed UK prescribers offer online clinical assessments for weight loss medication through registered pharmacies. A consultation fee and prescription costs apply, but treatment can begin more quickly.
First step: Speak to your GP about your weight and exercise goals. They can assess whether prescription medication is suitable for you and discuss both NHS and private options. Calculate your BMI using our free tool above to understand your starting point before that conversation.
- 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 exercise alone enough for weight loss?
Exercise is essential for health and supports weight loss, but the NHS emphasises that sustainable weight loss requires both increased physical activity and reduced calorie intake. Most people lose weight more effectively when combining exercise with dietary changes. For those with a BMI over 30 or weight-related health conditions, prescription medication alongside exercise can significantly improve results.
How much weight can I lose with exercise and medication together?
Results vary considerably between individuals. In clinical trials, people taking Mounjaro or Wegovy alongside a reduced-calorie diet and exercise lost 15–21% of body weight over 6–12 months. However, some people lose more, some less. Your prescriber will discuss realistic expectations based on your individual health and circumstances.
Can I get weight loss medication on the NHS?
Yes. If you have a BMI of 30 or above, or 27 or above with a weight-related health condition like type 2 diabetes, you may be eligible for NHS prescription weight loss treatment. Ask your GP for a referral to a specialist weight management service. Waiting times and availability vary by region, so check with your local NHS integrated care board.
What is the difference between Mounjaro and Wegovy?
Both are once-weekly injections for weight management in the UK. Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), whilst Wegovy (semaglutide) activates one (GLP-1). Clinical trial data suggests slightly higher average weight loss with Mounjaro, but individual responses vary. Your prescriber will recommend which is most suitable for you.
Can I stop taking weight loss medication and keep the weight off?
Weight loss medication works best as part of ongoing lifestyle changes. When people stop taking these medicines, some weight regain is common — which is why sustained exercise and healthy eating remain essential. Talk to your prescriber about long-term plans. Some people continue medication long-term for weight maintenance, others transition to lifestyle management alone. ```
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.