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
Can Coffee Help With Weight Loss?
Coffee is often promoted as a weight loss aid, but the reality is more nuanced. While caffeine may offer modest metabolic benefits, it's not a reliable standalone weight loss solution. If you're interested in effective weight management in the UK, prescription options like Mounjaro and Wegovy are available for eligible adults. This guide explores what coffee can realistically do for weight loss and how evidence-based medication can support your weight management journey.
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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 Options
For meaningful weight management in the UK, prescription medications approved for weight loss may be more effective than dietary supplements or foods alone. Three main options are currently licensed:
- Mounjaro (tirzepatide) — a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist. Clinical trials showed an average weight loss of 15–21% of body weight when combined with reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical trials demonstrated approximately 15% average body weight loss at the maximum dose.
- Saxenda (liraglutide) — a daily GLP-1 injection, an alternative if once-weekly doses don't suit you.
All three are prescription-only medicines. Eligibility is based on BMI and health status. Use our free BMI calculator above to check where you fall on the NHS weight categories, and our GLP-1 weight loss calculator to explore potential outcomes if you're interested in medication.
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 Access and Next Steps
Access to prescription weight loss medication through the NHS varies by region and typically requires referral to a specialist tier 3 weight management service. Waiting times can be lengthy in many areas. Alternatively, private prescribing is available through GPhC-registered online services following an online clinical assessment — this route is often faster and doesn't require an NHS referral.
To explore whether you might be eligible, start by calculating your BMI using our free tool on this page. If your BMI is 30 or above (or 27+ with weight-related health conditions), speak with your GP about prescription weight loss medication as part of your overall weight management strategy. They can advise on NHS options or discuss private routes if that suits you better.
- 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 caffeine actually help with weight loss?
Caffeine may have minor metabolic effects — it can increase energy expenditure slightly and may suppress appetite temporarily. However, these effects are modest and don't lead to significant weight loss on their own. For meaningful, sustained weight loss, dietary changes and lifestyle factors are far more important than coffee alone.
What's the difference between Mounjaro and Wegovy for weight management?
Both are once-weekly injections for weight management, but they work differently. Mounjaro uses dual GIP and GLP-1 action, whilst Wegovy uses GLP-1 alone. Clinical trial data shows both can support significant weight loss when combined with lifestyle changes. A prescriber can advise which might suit you better based on your individual health.
How do I find out if I'm eligible for prescription weight loss medication in the UK?
Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea). Use our free BMI calculator to check your category. Then discuss options with your GP, who can assess your full health picture and advise on NHS or private routes.
Can I get weight loss injections through the NHS, or do I need to go private?
Both options exist in the UK. NHS access is through specialist tier 3 weight management services — you typically need a GP referral and may face waiting lists. Private prescribing is faster and available without an NHS referral, though costs vary. Your GP can discuss both routes with you.
Should I rely on diet changes like drinking more coffee, or should I explore medication?
Coffee and diet are important foundations for weight management. However, if you've struggled with diet and exercise alone, prescription weight loss medication may help — especially if you're overweight or obese. The most effective approach often combines medication, reduced-calorie diet, and increased physical activity. A GP or prescriber can help you decide what's right for you.
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.