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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Fitness Schedule For Weight Loss: UK Health Guide
A fitness schedule is essential for sustainable weight loss, but exercise alone is rarely enough. Most UK adults achieve better results by combining regular physical activity with dietary changes and, where appropriate, prescription weight management options. This guide explains how to structure your fitness routine, whether you're managing weight loss independently or alongside medication like Mounjaro or Wegovy. Your GP can advise on the best approach for your individual health needs.
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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.
Prescription Weight Loss Options in the UK
For adults struggling with weight management despite fitness and diet efforts, prescription medication is available in the UK through NHS specialist services or private prescribing. Three main options are currently licensed:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, injected once weekly, maximum dose 15 mg. Clinical trials showed average weight loss of 15–21% body weight over 72 weeks alongside reduced-calorie diet and exercise.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, injected once weekly, maximum dose 2.4 mg. Clinical trials showed average weight loss of approximately 15% body weight.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, injected daily, maximum dose 3 mg. Available for eligible adults but requires daily rather than weekly administration.
Eligibility: You may qualify 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 sleep apnoea. Lower thresholds apply for adults of South Asian, Chinese, Black African, or Black Caribbean heritage. Individual results vary significantly — prescription medication works most effectively alongside your fitness schedule and dietary changes, not as a replacement.
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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: Finding the Right Route for You
NHS access requires referral to a specialist weight management service (tier 3) through your GP, though availability varies significantly by region and waiting lists can be lengthy. Private access is available through GPhC-registered online prescribing services following a clinical consultation — no NHS referral needed, though costs typically range from £129–£320 per month depending on dose.
Either route requires a prescriber to assess whether medication is suitable for you. Start by speaking with your GP about your weight loss goals and fitness schedule. They can discuss whether prescription options might help alongside your exercise routine and can refer you to NHS specialist services if appropriate. Calculate your BMI using our free BMI calculator above to understand your current health category, and explore how your fitness schedule might combine with other approaches supported by professional guidance.
- 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 lose weight through fitness alone without medication?
Yes, many people successfully lose weight through fitness and dietary changes alone. The NHS recommends losing 0.5–1 kg per week through a calorie deficit of approximately 500 kcal daily. However, some people benefit from combining exercise with prescription medication if they meet eligibility criteria and have discussed options with their GP.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, showing slightly higher average weight loss (15–21%) than Wegovy's single GLP-1 mechanism (approximately 15%) in clinical trials. Both are once-weekly injections. Wegovy requires dose escalation from 0.25 mg to 2.4 mg; Mounjaro starts at 2.5 mg and escalates to 15 mg. Individual results vary and prescriber assessment is required.
How do I know if I'm eligible for prescription weight loss medication in the UK?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Lower thresholds (BMI 27.5+) apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage. Speak to your GP or use our free BMI calculator to check your category and discuss options.
Should I stop exercising if I start weight loss medication?
No — prescription weight loss medications work most effectively alongside continued fitness, physical activity, and dietary changes. Your exercise schedule remains important. Weight loss medications help reduce appetite and support feeling fuller, but are not a replacement for lifestyle changes. Your prescriber will advise on how to combine medication with your fitness routine safely.
How long does it take to see weight loss results with medication?
Clinical trials typically show measurable weight loss within 4–8 weeks at therapeutic doses. However, maximum benefit usually appears after 16–20 weeks of consistent use alongside your fitness schedule and reduced-calorie diet. Individual results vary significantly. A prescriber will monitor your progress and adjust your dose or approach if needed.
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.