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 By Black Coffee: What Actually Works
Black coffee is often promoted as a weight loss aid — it contains caffeine, which may provide a small metabolic boost and reduce appetite temporarily. However, on its own, black coffee won't create the sustained weight loss most people need. If you're serious about losing weight, the NHS recommends combining dietary changes with increased activity. For eligible adults in the UK, prescription weight management options are also available. This guide explains what black coffee can and cannot do, and introduces you to evidence-based approaches that actually deliver results.
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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 Prescription Weight Loss Options
If black coffee and lifestyle changes alone aren't working, prescription weight loss medication is available in the UK for eligible adults. The most commonly prescribed options are:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. Clinical trials showed users lost an average of 15–21% of body weight over 72 weeks, alongside diet and activity changes.
- Wegovy (semaglutide) — a GLP-1 receptor agonist. The STEP-1 trial demonstrated approximately 15% average weight loss at the maximum dose.
- Saxenda (liraglutide) — a daily GLP-1 injection. Typically produces 5–clinically studied weight loss on average.
All three are prescription-only medicines. You're eligible if you have a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply. Individual results vary significantly — prescription medication works best alongside reduced-calorie diet and physical activity.
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.
Getting Started: NHS vs Private Routes
In the UK, you can access prescription weight management medication through two routes:
- NHS specialist services: Ask your GP for a referral to a tier 3 weight management service. Assessment is free, but waiting lists vary by region — some areas have significant delays. Not all regions offer the same medications.
- Private prescribing: Online consultations with UK-licensed prescribers are faster. You'll need a clinical assessment, and costs range from approximately £129–£320 per month depending on medication and dose.
Either way, a healthcare professional will assess your BMI, health history, and eligibility. If you're interested in exploring medication options, start by discussing weight management with your GP. They can refer you to specialist services or advise on private options. Use our free BMI calculator above to check your starting point, and try our GLP-1 weight loss calculator to explore potential outcomes at different medication doses.
- 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 black coffee actually help with weight loss?
Black coffee contains caffeine, which may slightly increase metabolism and reduce appetite in the short term. However, the effect is modest — typically equivalent to burning an extra 80–100 calories daily. On its own, black coffee won't create meaningful weight loss without a calorie deficit achieved through diet and activity changes. It can be part of a broader weight management approach, but it's not a solution alone.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections used for weight management in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist and typically produces slightly higher average weight loss (15–21%) compared to Wegovy (semaglutide), which is a GLP-1 agonist only (approximately 15% average loss). Both work best alongside diet and activity changes. A prescriber will assess which is more suitable for you.
Can I get weight loss medication on the NHS?
Yes, prescription weight loss medications including Mounjaro, Wegovy, and Saxenda are available on the NHS through specialist tier 3 weight management services. You'll need a referral from your GP. Eligibility requires a BMI of 30 or above (or 27–29.9 with weight-related conditions). Availability and waiting times vary significantly by region and NHS Integrated Care Board.
How much weight can I expect to lose with prescription medication?
Clinical trials show average weight loss of 5–21% of body weight depending on the medication and dose — but individual results vary significantly. Some people lose more, others lose less. Results are best when medication is combined with a reduced-calorie diet and increased physical activity. Your prescriber can give you a more personalised estimate based on your health profile.
What's the healthiest way to lose weight?
The NHS recommends losing weight at a rate of 0.5–1 kg per week through a combination of reduced-calorie diet (approximately 500 kcal daily deficit), regular physical activity, and behaviour change. For some eligible adults, prescription medication can support this process. Start by speaking with your GP about what approach suits you, and use our free BMI calculator and weight loss calculator to track your progress.
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.