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
Best Detox Weight Loss Tea — What Works in the UK?
Detox weight loss teas are popular but have limited scientific evidence for sustainable weight management. If you're looking for effective weight loss support in the UK, prescription medications like Mounjaro and Wegovy offer clinically proven options for eligible adults. This guide explains how prescription weight management works alongside lifestyle changes, and how to find out if you qualify for NHS or private treatment.
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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
If you're interested in medically supported weight loss in the UK, three prescription-only medications are licensed for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All are GLP-1 or GIP/GLP-1 receptor agonists that work differently from dietary supplements or teas.
- Mounjaro: Once-weekly injection, dual GIP and GLP-1 action, maximum dose 15 mg. Clinical trials showed average weight loss of 15–21% of body weight.
- Wegovy: Once-weekly injection, GLP-1 action only, maximum dose 2.4 mg. Average weight loss approximately 15% of body weight in clinical trials.
- Saxenda: Daily injection, GLP-1 action, maximum dose 3 mg. Less commonly prescribed than Mounjaro or Wegovy.
All require a prescription from a qualified healthcare professional and are used alongside a reduced-calorie diet and increased physical activity. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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 — How to Get Started
In the UK, prescription weight loss medication is available through two routes: the NHS or private prescription services. NHS access requires referral to a specialist tier 3 or 4 weight management service through your GP; availability varies significantly by region and waiting lists can be lengthy. Private access is available through online GPhC-registered pharmacies following a clinical assessment with a UK-licensed prescriber, with no NHS referral needed.
To find out if you're eligible, start by speaking with your GP about weight management options, or explore private assessment if NHS waiting times are long in your area. Calculate your BMI using our free BMI calculator above to understand your current weight category and discuss options with a healthcare professional.
- 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.
Is detox tea effective for weight loss?
Detox teas have very limited scientific evidence for weight loss. While some ingredients may have mild diuretic effects, any weight loss is usually temporary water loss, not sustainable fat loss. For evidence-based weight management, prescription medication or structured dietary changes are more reliable than supplements or teas.
Who is eligible for prescription weight loss medication in the UK?
Adults with a BMI of 30 or above, or 27 or above with weight-related health conditions (type 2 diabetes, high blood pressure, heart disease), may be eligible. Eligibility is assessed individually by a healthcare professional based on your health and medical history. Your GP can discuss whether treatment is appropriate for you.
How much weight can I expect to lose with Mounjaro or Wegovy?
Clinical trials showed average weight loss of 15–21% of body weight with Mounjaro and approximately 15% with Wegovy — though individual results vary significantly. Weight loss is achieved alongside a reduced-calorie diet and increased physical activity. Always discuss realistic expectations with your prescriber.
Can I get weight loss injections through the NHS?
Yes, Mounjaro and Wegovy are available through NHS specialist weight management services, but access varies by region and waiting lists are often long. Private access is available through GPhC-registered online pharmacies following a clinical assessment. Speak to your GP about both options.
Are prescription weight loss medications safe?
Mounjaro, Wegovy, and Saxenda are licensed, regulated medicines with established safety profiles. Common side effects include nausea and digestive changes, which usually improve over time. Serious side effects are rare but possible — your prescriber will assess your suitability and monitor your health throughout treatment.
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.