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
Weight Loss Exercises at Home — And When to Consider Medication
Regular exercise at home is an effective way to support weight loss when combined with dietary changes. However, for many UK adults struggling with excess weight, home workouts alone may not be enough. This guide covers practical home exercises for weight management alongside prescription options now available through the NHS and private prescribers for eligible adults with a BMI of 30 or above, or 27 or above with weight-related health conditions.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Prescription Weight Loss Options — Mounjaro, Wegovy, and Saxenda
If you're looking to lose weight in the UK, prescription medications are now available alongside lifestyle changes like home exercise. Mounjaro (tirzepatide) is a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist, helping regulate appetite and support feeling fuller. Wegovy (semaglutide) is another once-weekly option that activates the GLP-1 pathway. Saxenda (liraglutide) is a daily injection also approved for weight management.
In clinical trials, these medications helped participants lose an average of 15–21% of their body weight alongside reduced-calorie diets and increased physical activity. Individual results vary significantly. All three are prescription-only and require a clinical assessment to determine eligibility. Access is available through NHS specialist weight management services or private prescribers following an online consultation with a UK-licensed healthcare professional.
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 — How to Find Out If You're Eligible
To explore prescription weight loss medication through the NHS, ask your GP for a referral to your local tier 3 specialist weight management service. NHS access is free but availability varies by region and waiting lists can be lengthy in many areas. Private access is available immediately through GPhC-registered online pharmacies with a clinical assessment — costs typically range from £129–£320 per month depending on the medication and dose.
Eligibility is generally the same: BMI of 30 kg/m² or above, or 27 kg/m² or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our free BMI calculator above to check your starting point. Your GP can provide personalised advice about what's most appropriate for you.
- 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 with home exercises alone?
Yes, home exercise combined with a calorie deficit and balanced diet can support sustainable weight loss. The NHS recommends losing 0.5–1 kg per week. However, if you have a BMI over 30 or weight-related health conditions, your GP may suggest additional support including prescription medication alongside exercise.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Both are once-weekly injections. Clinical trials showed Mounjaro resulted in slightly higher average weight loss (15–21%) compared to Wegovy (around 15%), though individual results vary considerably.
How do I get prescription weight loss medication on the NHS?
Ask your GP for a referral to your local tier 3 specialist weight management service. You'll be assessed for eligibility and, if appropriate, prescribed medication. Alternatively, you can access private prescribing through an online consultation with a UK-licensed prescriber without an NHS referral.
Are prescription weight loss injections safe?
Prescription weight loss medications like Mounjaro and Wegovy have been through rigorous clinical trials and are approved by the MHRA for use in the UK. Side effects are typically mild (nausea, diarrhoea) and often improve over time. Always discuss risks and benefits with your prescriber.
Can I use the GLP-1 calculator to see potential weight loss?
Yes. Our free GLP-1 weight loss calculator on this page can help you estimate potential weight loss at different medication doses, based on clinical trial averages. Remember that individual results vary and the calculator provides projections, not assures.
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.