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 Body Detox Actually Help With Weight Loss?
Body detoxes are heavily marketed for weight loss, but the scientific evidence doesn't support most claims. Your body has its own detoxification system — your liver and kidneys already filter waste and toxins without needing special products. However, some detox-related lifestyle changes (like reducing processed foods or drinking more water) can support weight management. For sustained, evidence-based weight loss, the NHS recommends a combination of dietary changes, increased physical activity, and in some cases, prescription weight loss medication alongside lifestyle adjustments. Understanding what actually works is key to avoiding fad approaches that don't deliver results.
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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 Do "Body Detox" Products Actually Do?
Detox teas, supplements, and juices claim to flush toxins, boost metabolism, or "cleanse" your system. Scientific evidence shows these claims are largely unproven. Your liver and kidneys are highly efficient at removing waste — they don't need external products to work better. Many detox products contain high amounts of sugar (especially juices), caffeine, or herbs that can cause side effects like stomach upset or electrolyte imbalances.
- Detox diets: Often very restrictive, leading to short-term water weight loss but no sustainable fat loss. Once you stop, weight typically returns.
- Detox supplements: No regulatory requirement to prove they work. Some may interact with medications or cause adverse effects.
- Colon cleanses: Not recommended by the NHS — your colon self-regulates and unnecessary cleanses can disrupt gut bacteria.
The real value of "detox" thinking comes from what it encourages: eating more whole foods, drinking more water, and reducing processed items. These habits support weight loss — but it's the dietary change itself, not any special detoxifying effect.
Clinically BackedWeight Loss
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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
For sustainable weight management in the UK, the NHS recommends: a calorie deficit (around 500 kcal/day for approximately 0.5 kg per week loss), increased physical activity, and behaviour change support. For adults meeting specific criteria — such as a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes — prescription weight loss medication may be appropriate. GLP-1 weight loss injections like Wegovy (semaglutide) work by reducing appetite and food cravings, not by "detoxifying." Use our free BMI calculator to check where you stand, and our GLP-1 weight loss calculator to explore potential results with evidence-based medication. Your GP can assess whether prescription options suit your health profile.
- 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.
Are detox teas safe for weight loss?
Detox teas may contain caffeine and herbs that cause dehydration or digestive upset, creating temporary water weight loss. This isn't fat loss and the weight returns when you rehydrate. The NHS does not recommend detox teas for weight management. Sustainable loss comes from reducing calorie intake and increasing activity.
Can detox supplements boost metabolism?
No robust evidence supports detox supplements boosting metabolism significantly. Your metabolic rate is primarily determined by age, body composition, and genetics. Weight loss happens through calorie deficit, not metabolic "boosts." Always check with your GP before taking any supplement, as some interact with medications.
What's the difference between detox and actual weight loss?
Detox products target "toxins" (unproven for most claims), whereas weight loss requires creating a calorie deficit. Your liver and kidneys already detoxify efficiently. Real weight loss is fat loss — which requires reducing calorie intake, moving more, and ideally, sustained behaviour change over weeks and months.
Does the NHS recommend detox for weight loss?
No. The NHS recommends a calorie deficit of around 500 kcal/day, increased physical activity, and behaviour change support. For eligible adults, prescription weight loss medication (like Wegovy or Mounjaro) may be prescribed alongside lifestyle changes — not detox products.
What should I do instead of trying a detox?
Focus on eating more whole foods (fruits, vegetables, lean protein, whole grains), reducing processed items, drinking more water, and moving more regularly. If you need structured support, ask your GP about NHS weight management services, or use our BMI calculator and progress tracker to monitor your journey.
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.