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 Loss Coffee and UK Prescription Medication Options
While weight loss coffee claims to boost metabolism, the evidence for coffee's weight management effects is modest. For more significant weight loss, UK-licensed prescription medications like Mounjaro and Wegovy are available for eligible adults. These GLP-1 and dual-action medications, prescribed alongside lifestyle changes including diet and exercise, may help with weight loss uk more effectively than supplements alone. Understanding your BMI and eligibility is the first step—use our free BMI calculator above to check where you stand, then speak with your GP about prescription weight management options.
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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 Prescription Weight Loss Medications
Three prescription-only medications are currently licensed in the UK for weight management in adults:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks when combined with reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — GLP-1 receptor agonist, once-weekly injection. Average weight loss of approximately 15% body weight in clinical trials (STEP-1) over 68 weeks alongside lifestyle changes.
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection. Approved for weight management with similar evidence base to Wegovy.
All three require a prescription and are only prescribed following clinical assessment by a licensed healthcare professional. Individual results vary significantly.
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 Eligibility
In the UK, you can access prescription weight loss medication through NHS specialist services or private prescribing. NHS access requires referral to a tier 3 weight management service from your GP, though availability varies by region and waiting times can be lengthy. Private access is available through UK-licensed online prescribers following an online clinical assessment—no NHS referral needed. Eligibility for both routes includes: BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply due to increased health risks at lower weights. Speak with your GP first to discuss which route suits your situation.
- 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 help with weight loss?
Coffee contains caffeine, which may slightly boost metabolism and can reduce appetite temporarily. However, the effect is modest—typically contributing to minimal weight loss on its own. For sustainable weight management uk, coffee alone is insufficient. Diet and physical activity changes, potentially combined with prescription medication for eligible adults, are far more effective long-term.
Who is eligible for Mounjaro or Wegovy in the UK?
You may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Lower thresholds apply for certain ethnic backgrounds. A GP or licensed prescriber will assess your individual eligibility following a clinical consultation.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections for weight management, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) acts only on GLP-1. Clinical trial data suggests Mounjaro may produce slightly higher average weight loss (15–21% vs 15%), but individual results vary. Your prescriber will recommend which is most suitable for you.
Can I get Mounjaro or Wegovy on the NHS?
Yes, both are available through NHS tier 3 specialist weight management services. However, you typically need a GP referral, and availability varies significantly by region with potential waiting times of several months. Private access through UK-licensed online prescribers is an alternative, available without NHS referral.
How do I find out if weight loss medication is right for me?
Start by calculating your BMI using our free BMI calculator on this page—this helps you understand your current weight category. Then book an appointment with your GP to discuss weight management options. If eligible, your GP can refer you to NHS specialist services or discuss private prescribing options. A licensed prescriber will conduct a full clinical assessment before any medication is prescribed.
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.