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
Is Coffee Good for Weight Loss?
Coffee may have a modest effect on metabolism and appetite, but it's not a weight loss solution on its own. Whilst caffeine can provide a small metabolic boost, sustainable weight management in the UK requires a combination of dietary changes, physical activity, and for eligible adults, prescription medication may be considered. If you're struggling with your weight, understand what options are available to you through the NHS and private prescribing pathways.
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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 Available in the UK
For adults looking to lose weight, the UK offers several prescription weight loss medications that are clinically proven to support more significant results than dietary changes alone. These include:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks, alongside a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a GLP-1 receptor agonist. Evidence from clinical trials demonstrated average weight loss of around 15% of body weight.
- Saxenda (liraglutide) — a once-daily GLP-1 injection, approved for weight management in UK adults.
All are prescription-only medicines requiring clinical assessment. Weight management through nhs weight loss services or private prescribing involves a comprehensive approach combining medication with lifestyle support. Use our free GLP-1 weight loss calculator above to explore potential results at different doses, and check your current status with our BMI calculator.
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: How to Access Weight Loss Medication
In the UK, weight loss medication nhs access occurs through specialist tier 3 weight management services, usually requiring a GP referral. However, waiting lists can be lengthy in many areas. Alternatively, prescription weight loss uk is available privately through online consultations with UK-licensed prescribers, often with faster access.
To find out if you're eligible: adults with 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, may qualify. Your GP can advise on NHS options, or you can explore private prescribing. Either way, medication works best alongside dietary changes and increased physical activity. Our weight converter can help you check your weight in different units, and our progress tracker lets you monitor your journey.
- 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.
Does coffee actually boost weight loss?
Caffeine may slightly increase metabolism and suppress appetite for a short period, but the effect is modest — typically only 3–11% increase in calorie burn. Coffee alone won't cause meaningful weight loss. For more significant results, UK adults can access prescription weight loss medications like Mounjaro or Wegovy through NHS specialist services or private prescribing.
What's the difference between Mounjaro and Wegovy in the UK?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials showed Mounjaro achieved slightly higher average weight loss (15–21% vs 15%). Both are prescription-only and require clinical assessment. Your prescriber will determine which is more suitable for you.
Can I get weight loss medication through the NHS in the UK?
Yes. Weight loss medication is available through NHS specialist tier 3 weight management services, usually following a GP referral. However, availability and waiting times vary significantly by region. Your GP can discuss whether you're eligible and what options are available locally.
What's the eligibility for prescription weight loss medication in the UK?
Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (diabetes, high blood pressure, sleep apnoea, cardiovascular disease), may be eligible. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply. A GP or licensed prescriber will assess your individual circumstances.
How quickly will I lose weight on GLP-1 medication like Mounjaro or Wegovy?
Clinical trials showed average weight loss of around 0.5–1 kg per week at higher doses, though individual results vary significantly. Weight loss medication is most effective when combined with a reduced-calorie diet and increased physical activity. Use our free GLP-1 weight loss calculator to see projected results based on current clinical data.
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.