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 Tea For Weight Loss At Night — What Actually Works
While herbal teas like green tea and chamomile may offer modest metabolic benefits, they're not a solution for weight loss on their own. If you're looking for effective weight management in the UK, prescription medications like Mounjaro and Wegovy are available through NHS specialist services or private online prescribing following clinical assessment. This guide explains how prescription weight loss medication works, who's eligible, and how to start a conversation with your GP about your weight management options.
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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 adults looking for genuine prescription weight loss medication in the UK, three options are currently licensed: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Mounjaro and Wegovy are once-weekly injections; Saxenda is a daily injection. In clinical trials, Mounjaro helped participants lose an average of 15–21% of their body weight, while Wegovy showed average weight loss of around 15%. These are not quick fixes — they work alongside a reduced-calorie diet and increased physical activity. You can use our free GLP-1 weight loss calculator to estimate potential weight loss at different doses. Who is eligible? Adults with a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease may qualify for prescription weight loss treatment.
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 Access
NHS access: Ask your GP for a referral to a specialist weight management service (tier 3). Availability varies significantly by region, and waiting lists can be lengthy. Private access: Available through GPhC-registered online pharmacies following an online clinical assessment — no NHS referral needed. The prescriber will assess whether medication is suitable for you based on your health history. Either route requires a proper prescription and clinical judgment. Use our free BMI calculator to check your current BMI and understand where you stand. Starting a weight management journey also works better with tracking — our free progress tracker helps you log your results over time.
- 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.
Can tea or supplements cause significant weight loss?
No. While some teas contain compounds that may slightly boost metabolism, evidence shows they have minimal impact on weight. Sustainable weight loss requires a calorie deficit, lifestyle changes, and in many cases, medical support. Prescription medications like Mounjaro and Wegovy have robust clinical evidence behind them.
Am I eligible for prescription weight loss medication on the NHS?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like diabetes or high blood pressure. South Asian, Black African, Caribbean, and Chinese adults may qualify at lower BMI thresholds. Ask your GP for a referral to specialist weight management services in your area.
How much weight can I expect to lose with Mounjaro or Wegovy?
Clinical trials show average weight loss of 15–21% with Mounjaro and around 15% with Wegovy — but individual results vary significantly. Results depend on dose, adherence, diet, and exercise. Our GLP-1 weight loss calculator can help you understand projected outcomes.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), while Wegovy (semaglutide) activates one (GLP-1). Both are once-weekly injections. Mounjaro typically shows slightly higher average weight loss in trials, but results vary by individual. Your prescriber will advise which is suitable for you.
Can I get prescription weight loss medication privately if I don't qualify for NHS treatment?
Yes. Private online prescribing is available through GPhC-registered pharmacies. You'll have an online consultation with a UK-licensed prescriber who will assess eligibility based on your health. This route doesn't require an NHS referral and can be faster, though it involves private costs.
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.