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 Detox Actually Help You Lose Weight?
The idea of "detoxing" to lose weight is popular in the UK, but the science behind it is more complex than marketing claims suggest. Your body naturally removes toxins through your liver and kidneys — you don't need special detox products or extreme cleanses to do this. However, some detox-style approaches may indirectly support weight loss by encouraging healthier eating habits and increased water intake. This guide explains what the evidence actually shows about detox for weight management and explores proven alternatives.
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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.
What Does "Detox" Really Mean for Weight Loss?
"Detox" in the weight loss context typically refers to juice cleanses, fasting periods, detox teas, or commercial detox products claiming to flush toxins and kickstart weight loss. The problem: your liver and kidneys already detoxify your body continuously — you don't need external products to do this. Research shows most commercial detox products lack scientific evidence for weight loss claims.
- Juice cleanses: Often very low in calories, creating short-term weight loss that's mostly water and muscle, not fat loss
- Detox supplements: Generally unregulated and lacking clinical trial support for weight loss claims
- Fasting detox periods: May reduce calorie intake temporarily but rarely lead to sustained weight management without lifestyle changes
- Detox teas: May contain laxatives that create water loss, not true fat loss
Weight loss from detox approaches is usually regained once normal eating resumes, making them ineffective for long-term weight management in the UK health system.
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 Approaches to Weight Management
Instead of detox, the NHS recommends sustainable weight loss at 0.5–1 kg per week through reduced-calorie diet and increased physical activity. For adults with a BMI over 30, or 27–29.9 with weight-related health conditions like high blood pressure or prediabetes, prescription weight loss medication may be appropriate alongside lifestyle changes. GLP-1 weight loss injections help reduce appetite and support gradual, sustainable weight management. Use our free BMI calculator to check your current range, and our GLP-1 weight loss calculator to explore potential outcomes with medical support. Your GP can assess whether prescription weight loss options are suitable for you.
Sustainable weight management combines realistic dietary changes, regular physical activity, and behavioural support. Rather than seeking quick fixes through detox, focus on: eating whole foods, reducing processed sugar and calories, drinking adequate water (which detox culture gets right), and building consistent exercise habits. For weight management in the UK, the weight converter tool helps you track progress in stone or kilograms — whatever feels natural. Evidence shows that slow, steady progress with professional support outperforms extreme approaches every 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.
Do detox teas and supplements actually help you lose weight?
Most detox teas and supplements lack clinical evidence for weight loss. Some contain laxatives that create temporary water loss, not fat loss. Unregulated supplements may not contain what they claim. The NHS does not recommend detox products for weight management — sustainable approaches through diet and exercise are evidence-based.
What's the difference between water loss and real fat loss?
Detox approaches often cause rapid water loss, which returns when you rehydrate. Real fat loss requires a calorie deficit over weeks and months. Water loss feels dramatic but isn't sustainable. The NHS recommends aiming for 0.5–1 kg per week, which is mostly fat loss with lifestyle changes.
Why does my body need detoxing if I eat normally?
Your liver and kidneys detoxify your body continuously — you don't need special products or cleanses. These organs filter waste 24/7. Detox culture exaggerates the need for external intervention. A balanced diet, adequate water, and normal bodily function are all your body requires.
Is intermittent fasting the same as detox?
Intermittent fasting (like 16:8) is different from detox — it's a structured eating pattern that may support calorie reduction. Some people find it helpful for weight management, but results are similar to standard calorie restriction. It's not a "detox" but rather a meal timing approach. Always check with your GP before starting any fasting regimen.
What's the most effective way to lose weight sustainably in the UK?
The NHS recommends combining a reduced-calorie diet (500 kcal deficit for ~0.5 kg/week loss) with increased physical activity. For eligible adults, prescription weight loss medication alongside lifestyle changes may be appropriate. Your GP can assess your BMI and health conditions to recommend the right approach for you.
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.