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
Detox Juice Cleanse and Weight Loss — What Actually Works
Detox juice cleanses are popular but lack scientific evidence for sustainable weight loss. While marketing claims suggest rapid results, most weight lost is water, not fat. If you're looking for genuine weight management in the UK, prescription medications like Mounjaro and Wegovy offer evidence-based alternatives. These are available through the NHS and private prescribers for eligible adults. Let's explore what the science actually says and what medically-supported options exist for weight loss in the UK.
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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-Licensed Prescription Weight Loss Options
If detox cleanses aren't delivering results, prescription weight management medications are available in the UK for eligible adults. The most commonly prescribed options are:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist. In clinical trials, participants lost an average of 15–21% of their body weight alongside a reduced-calorie diet and increased physical activity. Doses range from 2.5 mg to 15 mg, injected once weekly.
- Wegovy (semaglutide) — A GLP-1 receptor agonist. Clinical trials showed average weight loss of around 15% of body weight. Maximum dose is 2.4 mg, also injected once weekly.
- Saxenda (liraglutide) — Another GLP-1 option, but requires a daily injection rather than weekly.
All three are prescription-only and require clinical assessment to determine eligibility. Results vary significantly between individuals, and medications work best when combined with dietary changes and increased physical activity — not as a standalone solution.
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.
Who Can Access Weight Loss Medication in the UK
Eligibility for prescription weight loss medication depends on your BMI and health profile. Use our free BMI calculator to check your personal BMI instantly. Adults with a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea), may qualify. For South Asian, Chinese, Black African, or Black Caribbean adults, the NHS recommends lower thresholds due to higher health risks at the same BMI. Access routes include NHS specialist weight management services (referral from your GP, variable waiting times by region) or private online prescribers following a clinical assessment. Your GP can discuss which option is most appropriate for your situation.
- 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 cleanses actually help with weight loss?
Detox juice cleanses may produce rapid initial weight loss, but this is primarily water loss, not sustainable fat loss. There's no scientific evidence that cleanses remove toxins — your liver and kidneys already do this naturally. Most people regain weight quickly after finishing a cleanse. The NHS does not recommend cleanses for weight management.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1-only medication. Both are once-weekly injections and have similar clinical efficacy (around 15–20% average weight loss). Mounjaro tends to produce slightly higher average weight loss in trials. The choice depends on individual health factors and prescriber assessment.
Can I get prescription weight loss medication through the NHS?
Yes, prescription weight loss medications are available through NHS specialist weight management services. You'll need a referral from your GP to tier 3 or tier 4 services. Availability and waiting times vary significantly by region. Private online prescribers also offer these medications following a clinical assessment if you prefer faster access.
How much weight can I expect to lose with Mounjaro or Wegovy?
Clinical trials show average weight loss of 15–21% of body weight with Mounjaro and around 15% with Wegovy — but individual results vary considerably. Some people lose more, others less. These medications work best alongside a reduced-calorie diet and increased physical activity. Your GP or prescriber can discuss realistic expectations for your situation.
What's the safe rate of weight loss?
The NHS recommends losing no more than 0.5–1 kg (1–2 lbs) per week for sustainable, healthy weight loss. This typically requires a calorie deficit of around 500 kcal per day. gradual weight management can cause muscle loss and nutrient deficiencies. Try our free weight loss calculator to estimate realistic timelines based on different approaches.
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.