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
Flat Stomach Detox Juice Recipes For Weight Loss
While detox juice recipes are popular for digestive health and feel-good nutrition, there's limited evidence that juice alone creates lasting weight loss. If you're looking for structured weight management in the UK, prescription options like Mounjaro and Wegovy are available for eligible adults. This guide covers both juice-based nutrition approaches and the evidence-backed medication alternatives your GP can discuss with you.
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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 Available Now
If you're struggling with weight management in the UK, prescription weight loss medications are available through both NHS and private prescribing. The three main UK-licensed options are:
- Mounjaro (tirzepatide) — a once-weekly injection that works on two appetite hormones. Clinical trials showed an average weight loss of 15–21% body weight.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Average weight loss in trials was around 15% body weight.
- Saxenda (liraglutide) — a daily injection option for those preferring more frequent dosing.
You're eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Calculate your BMI using our free BMI calculator above to check where you stand. All three medications work alongside diet and increased physical activity — they're not replacements for lifestyle change.
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, you have two main routes to prescription weight loss medication:
- NHS route: Ask your GP for a referral to a tier 3 specialist weight management service. Availability and waiting times vary significantly by region — some areas have shorter waits than others.
- Private route: Online prescribing through a GPhC-registered pharmacy. You'll have an online clinical assessment with a UK-licensed prescriber. This route is faster but involves a private cost, typically £129–£320 per month depending on dose.
If lifestyle changes alone haven't worked, or if you have weight-related health complications, have a conversation with your GP. They can assess your individual eligibility and discuss which option suits you best. Track your progress with our free progress tracker as you work towards your weight management goals.
- 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.
Do detox juice recipes actually help with weight loss?
Detox juices can support hydration and provide nutrients, but there's no strong scientific evidence that they cause lasting weight loss. Weight loss requires a calorie deficit. For sustainable results, the NHS recommends a structured approach combining diet and activity alongside, if eligible, prescription support.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) activates two appetite hormones — GIP and GLP-1 — and showed slightly higher average weight loss in trials (15–21% vs 15% for Wegovy). Wegovy (semaglutide) uses GLP-1 only. Both are once-weekly injections. Individual results vary. Your prescriber can advise which suits you.
How much weight can I expect to lose with prescription medication?
Clinical trials showed average weight loss of 15–21% body weight with these medications over several months, alongside reduced-calorie diet and increased activity. However, individual results vary significantly. Some people lose more, some less. A prescriber will discuss realistic expectations for your situation.
Can I get weight loss injections on the NHS?
Yes, Mounjaro and Wegovy are available on the NHS through specialist tier 3 weight management services. You'll need a GP referral. Availability varies by region — some areas have shorter waiting times than others. Your GP can advise on local pathways.
Is prescription weight loss medication right for me?
Eligibility depends on your BMI and health conditions. Use our free BMI calculator above to check your starting point, then speak to your GP. They can assess whether medication is appropriate for you based on your medical history and weight management goals.
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.