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 Detoxifying Water Help With Weight Loss?
Detoxifying water — often called "detox water" or infused water — is promoted as a weight loss aid, but the evidence is limited. While staying hydrated is essential for health and can support weight management, adding lemon, cucumber, or other ingredients doesn't magically "detoxify" your body or burn fat. Your kidneys and liver already detoxify naturally. However, drinking more water and less sugary drinks can genuinely help with weight loss. If you're serious about losing weight in the UK, understanding realistic strategies — including NHS guidance, prescription weight loss options, and our BMI calculator — will serve you far better than detox water alone.
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.
What Does "Detoxifying Water" Actually Do?
Detoxifying water is simply water infused with fruits, vegetables, or herbs — typically lemon, cucumber, mint, or berries. Marketing claims suggest it "flushes toxins", boosts metabolism, or increases fat burning. The reality is more modest.
Your body has natural detoxification systems: your liver filters waste, your kidneys remove it through urine, and your lymphatic system manages fluid balance. No special water formula improves these processes. However, drinking adequate water does support weight management in several genuine ways:
- Drinking water before meals can help you feel fuller, reducing overall calorie intake
- Water has zero calories, so replacing sugary drinks with water creates a calorie deficit
- Proper hydration supports metabolism and energy levels for physical activity
- Sometimes thirst is mistaken for hunger — drinking water can reduce unnecessary snacking
The weight loss benefit comes from the water itself and lifestyle changes, not from any "detoxifying" properties of added ingredients.
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.
Evidence-Based Weight Loss: What Actually Works
If you're aiming for sustainable weight loss in the UK, the NHS recommends losing 0.5 to 1 kg per week through a combination of dietary changes and increased physical activity. This means a calorie deficit of around 500 kcal per day.
For some adults, prescription weight loss medication may be appropriate. Weight management injections like GLP-1 medications are available through the NHS or private prescribing if you meet eligibility criteria (BMI 30 or above, or 27+ with weight-related health conditions). These work alongside diet and exercise — not as standalone solutions. Try our GLP-1 weight loss calculator to estimate potential results, and use our BMI calculator to understand where you stand. Drinking plenty of water supports any weight loss plan, but it works best combined with real dietary changes and professional guidance.
- 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 water better than regular water for weight loss?
No. Regular water and detox water are equally hydrating. The weight loss benefit comes from drinking water instead of sugary drinks and feeling fuller — not from added ingredients. Plain water is just as effective, cheaper, and simpler.
Can lemon water boost metabolism and burn fat?
There's no scientific evidence that lemon water significantly boosts metabolism or burns fat. While lemon adds vitamin C and flavour, it doesn't have a metabolic effect. Staying hydrated supports your body's natural functions, but that's true of plain water too.
What's the real connection between water and weight loss?
Drinking adequate water helps weight loss by reducing calorie intake (water has no calories), increasing satiety before meals, preventing thirst-hunger confusion, and supporting physical activity. These benefits apply to any water — no special ingredients needed.
Should I drink detox water instead of following NHS weight loss advice?
No. Detox water is a minor support at best. The NHS recommends realistic dietary changes, increased physical activity, and a calorie deficit of around 500 kcal per day. If you need additional support, your GP can refer you to weight management services or discuss prescription options.
Are there any risks to drinking detox water daily?
Detox water itself is safe for most people. However, be cautious with large amounts of lemon (acidic — can erode tooth enamel) or herbs like comfrey. Always brush teeth after acidic drinks. Focus on sustainable habits: balanced diet, regular exercise, adequate water, and professional guidance from your GP if needed.
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.