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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Weight Training and Weight Loss in the UK
Weight training and weight loss often work better together. Building muscle through resistance exercise can support your body composition whilst prescription weight management options like Mounjaro and Wegovy help reduce appetite and support sustainable weight loss. This guide explores how weight training fits with weight loss medication available in the UK, eligibility criteria, and how to start a conversation with your GP about prescription options if you're 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.
UK-Licensed Weight Loss Medications
Several prescription weight loss medications are available through the NHS and private prescribing in the UK. Mounjaro (tirzepatide) is a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist, helping to reduce appetite and support feeling fuller after meals. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks — though individual results vary. Wegovy (semaglutide) is also a once-weekly GLP-1 injection, with trial data showing average weight loss around 15% of body weight. Saxenda (liraglutide) is a daily GLP-1 injection, an older option with established safety data.
All three are prescription-only medicines requiring a clinical assessment before being prescribed. You're typically eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply due to higher health risks at lower weights.
These medications work best alongside lifestyle changes — including weight training, a reduced-calorie diet, and increased physical activity. Use our free BMI calculator to check where you currently stand against NHS guidelines.
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 in the UK
NHS access: You can ask your GP for a referral to a specialist tier 3 weight management service, where a multidisciplinary team (including doctors, dietitians, and psychologists) will assess whether prescription medication is appropriate for you. However, NHS services have limited availability and waiting lists can be lengthy in many areas — access varies significantly by region.
Private access: You can access prescription weight loss medication through private online prescribing services. A UK-licensed prescriber will review your health via an online consultation and issue a prescription if appropriate, dispensed by a GPhC-registered pharmacy. This route bypasses NHS waiting lists but involves private costs, typically ranging from £129–£320 per month depending on dose.
Regardless of route, weight training combined with prescription medication and dietary changes typically produces better, more sustainable results than medication alone. Track your progress using our free progress tracker.
- 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 weight loss medication if I do weight training?
Yes. Weight training and weight loss medication work well together. Medication helps reduce appetite whilst you maintain or build muscle through resistance exercise. Always inform your prescriber about your exercise routine — they can advise on nutrition and timing to support both weight loss and muscle preservation.
How do I know if I'm eligible for weight loss medication on the NHS?
You're eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes or high blood pressure. Lower thresholds apply for South Asian and Black African/Caribbean adults. Ask your GP for a referral to your local tier 3 specialist weight management service — they'll assess you formally.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with slightly higher average weight loss (15–21%) in trials. Wegovy (semaglutide) is a GLP-1 agonist only, with average weight loss around 15%. Individual results vary — your prescriber will recommend based on your health profile.
Will weight loss medication work without exercise?
Medication can help reduce appetite and support weight loss without exercise, but results are better when combined with physical activity and dietary changes. Weight training specifically helps preserve muscle mass during weight loss, which is important for metabolism and long-term success.
How long does it take to see results with weight loss medication?
Most people notice appetite reduction within 1–2 weeks. Measurable weight loss typically becomes apparent after 4–8 weeks. Clinical trials measured results at 68–72 weeks. Results vary significantly between individuals — your prescriber can discuss realistic timelines for your situation.
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.