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 Detox For Weight Loss — What Actually Works
The term "detox" is widely used in weight loss discussions, but what does it actually mean for your health? In the UK, the NHS and medical professionals focus less on "detoxes" and more on sustainable weight management through calorie deficit, balanced nutrition, and increased activity. If you're looking to lose weight effectively, evidence-based approaches—including prescription weight loss medication when appropriate—are far more reliable than commercial detox products. This guide explains what works and what doesn't, based on NHS guidance and clinical evidence.
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.
Understanding "Detox" and Weight Loss
The word "detox" often implies your body contains toxins that need removing. However, your liver and kidneys are designed to filter waste naturally—you don't need a special detox to do this. Many commercial detox products (teas, supplements, cleanses) lack strong scientific evidence and can be expensive or ineffective.
What actually helps with weight loss:
- Creating a calorie deficit of around 500 kcal per day for approximately 0.5 kg (1 lb) loss per week
- Eating whole foods: vegetables, lean proteins, whole grains, and healthy fats
- Staying hydrated—drinking water naturally supports metabolism and reduces hunger
- Increasing physical activity through walking, strength training, or other exercise
- Getting adequate sleep and managing stress
The NHS Weight Loss Plan offers free support for sustainable weight management. You can also use our free BMI calculator to assess where your current weight sits and track progress with our weight loss tracker as you make changes.
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.
Prescription Weight Loss Options in the UK
If lifestyle changes alone aren't sufficient, prescription weight loss medications are available in the UK for eligible adults. Wegovy (semaglutide) and Mounjaro (tirzepatide) are GLP-1 receptor agonist injections that help reduce appetite and support weight management when combined with diet and exercise.
Eligibility: Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions, may be prescribed these medications following clinical assessment. These are prescription-only medicines—you cannot buy them over the counter.
In clinical trials, Wegovy helped people lose an average of 14.9% of their body weight, and Mounjaro showed results of 15–21%. However, individual results vary significantly. Our GLP-1 weight loss calculator can help you estimate potential outcomes at different doses.
- 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 a detox tea or cleanse effective for weight loss?
Most commercial detox teas and cleanses lack strong scientific evidence. They may cause temporary water loss (not fat loss) and are often unnecessary since your body naturally detoxifies through your liver and kidneys. Weight loss requires a calorie deficit and sustainable lifestyle changes, not detox products.
What's the fastest safe way to lose weight in the UK?
The NHS recommends losing 0.5–1 kg (1–2 lbs) per week through a balanced diet and exercise. Very gradual weight management can lead to muscle loss and nutritional deficiency. If you need faster results, your GP can refer you to a specialist weight management service where prescription medications may be considered.
Can I use Wegovy or Mounjaro without a prescription?
No. Both Wegovy and Mounjaro are prescription-only medicines licensed in the UK. You cannot buy them over the counter. You'll need a clinical assessment from a licensed prescriber to determine if they're suitable for you, whether through NHS specialist services or private prescribing.
What counts as a healthy calorie deficit for weight loss?
A deficit of approximately 500 kcal per day typically results in losing around 0.5 kg per week. This can be achieved through eating less, moving more, or a combination of both. Very low-calorie diets (under 800 kcal/day) should only be followed under medical supervision.
Do I need to "detox" before starting weight loss medication?
No. If you're eligible for prescription weight loss treatment like Mounjaro or Wegovy, you can start directly after your clinical assessment. No pre-treatment detox is needed. These medications work best alongside a healthy diet and increased physical activity—which naturally support your body's functions. ```
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.