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 In Weight Loss?
Coffee can play a small supportive role in weight management — it contains caffeine, which may boost metabolism slightly and reduce appetite temporarily. However, coffee alone won't lead to meaningful weight loss. For adults in the UK with excess weight, the most effective approach combines lifestyle changes like diet and activity with evidence-based prescription weight loss medication if eligible. This guide explains how coffee fits into weight loss, and what medically-approved options are available through the NHS or privately.
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
If you're looking to lose weight in the UK, prescription weight loss medications are available to eligible adults alongside lifestyle changes. Three main options are licensed in the UK:
- Mounjaro (tirzepatide) — a once-weekly GLP-1 injection with dual hormone action. Clinical trials showed participants lost an average of 15–21% body weight.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Evidence from clinical trials demonstrated average weight loss of around 15% body weight.
- Saxenda (liraglutide) — a daily GLP-1 injection. Results are comparable to Wegovy.
All three are prescription-only medications requiring clinical assessment. Eligibility is based on your BMI and health profile. Use our free GLP-1 weight loss calculator to estimate potential outcomes at different doses, and our BMI calculator to check where you fall on the NHS scale.
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 — Which Route Is Right?
NHS route: Available through specialist tier 3 weight management services following GP referral. Waiting lists vary significantly by region (ICB) — some areas offer rapid access, others have waits of months or longer.
Private route: Available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. No NHS referral needed, though costs range from approximately £130–£320 monthly depending on dose.
To find out if you're eligible, speak to your GP about your weight management goals. They can assess whether prescription medication is appropriate for you and discuss whether the NHS pathway or private route is most suitable.
- 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 in coffee speed up weight loss?
Caffeine may boost metabolism slightly and reduce appetite temporarily, but the effect is modest — typically burning only 80–100 extra calories per day. Coffee alone won't lead to meaningful weight loss. For sustainable results, combine lifestyle changes (diet and activity) with prescription weight loss medication if eligible.
Can I drink coffee while taking Mounjaro or Wegovy?
Yes, coffee is generally safe while taking GLP-1 medications like Mounjaro or Wegovy. However, if you experience nausea or stomach sensitivity (common side effects), you may want to limit coffee initially. Always check with your prescriber about your specific situation.
How much weight can I realistically lose with prescription weight loss medication in the UK?
Clinical trials show average weight loss of 15–21% body weight with Mounjaro and around 15% with Wegovy, achieved over 12–18 months alongside a reduced-calorie diet and increased physical activity. Individual results vary significantly — some people lose more, some less. Your prescriber can discuss realistic outcomes based on your health profile.
What's the difference between NHS and private weight loss medication in the UK?
The medication is the same — NHS and private prescriptions contain identical active ingredients. The main difference is access route and timeline. NHS access requires GP referral and specialist assessment (variable waiting times); private access is faster but involves out-of-pocket costs. Both require a clinical assessment.
Am I eligible for prescription weight loss medication on the NHS?
Eligibility depends on your BMI and health. Generally, you may qualify if your BMI is 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. Use our free BMI calculator to check your BMI, then discuss eligibility with your GP.
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.