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
Glucomannan and Chromium Weight Loss Reviews — What Works in the UK?
Glucomannan and chromium are widely promoted as natural weight loss supplements, but if you're looking for clinically proven weight management options in the UK, prescription medications offer stronger evidence. For adults struggling with their weight, understanding the difference between supplements and medical treatments can help you make an informed decision about which approach suits your situation. This guide covers both supplement reviews and the prescription weight loss medications available through the NHS and private providers.
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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 Medication
If you're exploring weight management in the UK, prescription medications offer more robust clinical evidence than most supplements. Three prescription weight loss medications are currently licensed for UK adults:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of their body weight over 72 weeks when combined with lifestyle changes.
- Wegovy (semaglutide) — a GLP-1 receptor agonist. STEP trial data showed approximately 15% average body weight loss at the maximum dose.
- Saxenda (liraglutide) — a daily GLP-1 injection. Evidence supports modest weight loss alongside reduced-calorie diet and physical activity.
All three are prescription-only medicines requiring clinical assessment. Try our free GLP-1 weight loss calculator to see potential outcomes at different doses — individual results vary significantly based on lifestyle, metabolism, and adherence.
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.
Eligibility and How to Access Weight Loss Treatment
In the UK, you may be eligible for prescription weight loss medication if you have a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea.
NHS access: Referral through your GP to a specialist tier 3 weight management service. Availability varies by region and waiting times can be lengthy.
Private access: Available through online prescribers following a clinical assessment — no NHS referral needed.
Check your BMI using our free BMI calculator above. Your GP can advise whether prescription treatment is appropriate for you, or you can explore private options if you meet eligibility criteria.
- 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.
How does glucomannan for weight loss compare to prescription medication?
Glucomannan is a dietary fibre supplement with modest evidence for modest appetite reduction. Prescription GLP-1 medications like Wegovy and Mounjaro have much stronger clinical trial evidence (15–21% average body weight loss). Prescription options require a GP assessment or private prescription. Supplements are unregulated and available over-the-counter.
Is chromium effective for weight loss in the UK?
Chromium is marketed for weight management, but clinical evidence is limited and mixed. Most studies show minimal impact on weight loss compared to placebo. UK-licensed prescription medications have far more robust evidence. Talk to your GP if you're considering any supplement or medication.
Can I get prescription weight loss medication on the NHS?
Yes, if eligible. You'll need referral from your GP to a specialist weight management service. Eligibility requires BMI ≥30 or BMI 27–29.9 with weight-related health conditions. Availability varies significantly by region. Private prescription is an alternative if NHS waiting times are long.
What's the best way to check if I'm eligible for weight loss treatment?
Calculate your BMI using our free BMI calculator on this page. If your BMI is 27 or above, or you have weight-related health conditions, discuss prescription weight loss options with your GP. They can assess whether medication suits your individual health profile.
How can I track my progress with weight loss medication?
Use our free progress tracker to log your weight, measurements, and health improvements over time. Tracking non-scale victories like energy levels and fitness improvements is equally important. Share your progress with your GP or prescriber — they may adjust your dose based on your response.
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.