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
Does Drinking Tea Help with Weight Loss?
While drinking tea—particularly green and black varieties—may offer modest metabolic benefits, it's not a standalone weight loss solution. Tea contains compounds like catechins and caffeine that may slightly increase fat burning, but the effect is small. For meaningful weight management in the UK, most people benefit from a combination of dietary changes, physical activity, and sometimes prescription medication. Our free BMI calculator can help you understand your current weight category, and if you're eligible, your GP can discuss evidence-based treatment options available through NHS services or private providers.
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.
Prescription Weight Loss Options Available in the UK
For adults struggling with weight management, several prescription weight loss medications are licensed in the UK and have strong clinical evidence behind them. These are far more effective than dietary supplements or tea alone.
Three main options are available:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist. Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks when combined with diet and exercise.
- Wegovy (semaglutide) — A GLP-1 receptor agonist. The STEP trials demonstrated average weight loss of approximately 15% body weight at the maximum dose.
- Saxenda (liraglutide) — A daily GLP-1 injection. Evidence shows average weight loss of 5–10% body weight depending on dose.
All three are prescription-only medicines requiring a clinical assessment. Our GLP-1 weight loss calculator can help you explore potential outcomes at different doses, though 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 Eligibility and How to Access Weight Loss Treatment
You may be eligible for prescription weight loss treatment through the NHS or private providers 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 sleep apnoea. Use our free weight converter and BMI calculator to check your current category.
NHS access is through specialist tier 3 weight management services (your GP can refer you), though waiting times vary by region. Private online prescribing is also available in the UK following a consultation with a licensed prescriber. Either way, your eligibility and suitability will be assessed individually. If you're interested in exploring medication options, have a conversation with your GP about which route suits your situation best.
- 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 green tea actually help you lose weight?
Green tea contains catechins and caffeine, which may modestly increase metabolism and fat burning. Studies show the effect is small—typically an extra 50–100 calories burned per day. Combined with diet and exercise, it may contribute to weight loss, but it's not significant on its own. It's best viewed as a healthy beverage rather than a weight loss tool.
What's more effective for weight loss—tea or prescription medication?
Prescription weight loss medications like Mounjaro and Wegovy are far more effective than tea. Clinical trials show these medications help people lose 15–21% of body weight when combined with lifestyle changes. Tea alone has a negligible effect. If you're eligible for prescription treatment, your GP or a licensed prescriber can discuss whether it's appropriate for you.
Can I lose weight with just tea and diet changes?
You can lose weight with dietary changes alone through a calorie deficit, but adding physical activity makes it more sustainable. Tea won't accelerate this process meaningfully. If you've tried diet and exercise without success, prescription weight loss treatment may be worth discussing with your GP, especially if you have a BMI over 30 or weight-related health conditions.
How do I know if I'm eligible for NHS weight loss medication?
NHS eligibility typically requires a BMI of 30 or above, or 27–29.9 with comorbidities like diabetes. You'll also be assessed for other health factors. Your GP can help determine eligibility and refer you to specialist weight management services. Alternatively, private online prescribing is available if you prefer faster access.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are prescription GLP-1-based medications licensed for weight management in the UK. Mounjaro is a dual GIP/GLP-1 agonist with slightly higher average weight loss (15–21%). Wegovy is a GLP-1 agonist alone (approximately clinically studied weight loss). Both are once-weekly injections. A prescriber will assess which is more suitable for your individual circumstances.
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.