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
Berberine Weight Loss: What the Evidence Shows
Berberine is a plant alkaloid that has become popular in weight loss discussions, often marketed with before-and-after comparisons. However, evidence for berberine's weight loss effectiveness in humans is limited compared to prescription weight management options available in the UK. If you're interested in evidence-based weight loss support, prescription medications and NHS weight loss services offer clinically proven alternatives. This guide explains what we know about berberine, compares it to UK-licensed weight management options, and shows you how to access professional support if you're eligible.
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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 you're exploring weight loss solutions, the UK has several prescription medications available for eligible adults. These options have undergone rigorous clinical trials and are approved by the MHRA for weight management.
- Mounjaro (tirzepatide) — A once-weekly injection that activates dual GIP and GLP-1 pathways. In clinical trials, users lost an average of 15–21% of body weight over 72 weeks, though individual results vary significantly.
- Wegovy (semaglutide) — A once-weekly GLP-1 injection. Clinical evidence shows average weight loss of around 15% of body weight, alongside reduced-calorie diet and increased physical activity.
- Saxenda (liraglutide) — A daily GLP-1 injection, available for those who prefer a different injection frequency.
All three are prescription-only medicines and require clinical assessment before being prescribed. Unlike supplements like berberine, these medications have substantial clinical trial data supporting their use for weight management in the UK.
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 Is Eligible and How to Access Support
To be eligible for prescription weight loss medication in the UK, you typically need a BMI of 30 kg/m² or above, or 27–29.9 kg/m² if you have weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Check your personal BMI using our free BMI calculator above.
You can access prescription weight loss medication through the NHS (via specialist tier 3 services — though waiting lists vary by region) or through private online prescribing following a clinical assessment. Your GP can discuss which route is most suitable for you and whether you meet the eligibility criteria. If you're interested in tracking your weight loss progress, our free progress tracker can help log your journey over 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.
Is berberine effective for weight loss?
Berberine shows modest effects in some animal and small human studies, typically resulting in weight loss of 2–3 kg over several weeks. However, evidence is limited compared to prescription medications. The UK has clinically proven prescription options (Mounjaro, Wegovy) with much stronger evidence for sustainable weight loss. Speak to your GP about what's appropriate for you.
Why are prescription weight loss injections more reliable than berberine?
Prescription GLP-1 and GIP/GLP-1 medications have undergone rigorous clinical trials with thousands of participants, showing consistent average weight loss of 15–21% of body weight. Berberine studies are smaller and show variable results. Prescription medications are regulated by the MHRA and require proper clinical assessment. Always consult your GP for personalised advice.
Can I use berberine alongside prescription weight loss medication?
This should only be discussed with your prescriber or GP. Berberine may interact with certain medications, and combining supplements with prescription medication requires professional guidance. Never start any new supplement or medication without informing your healthcare provider of all substances you're taking.
How do I find out if I'm eligible for prescription weight loss treatment on the NHS?
Eligibility typically requires a BMI of 30 or above (or 27+ with weight-related health conditions). Start by speaking to your GP, who can assess your individual circumstances and discuss NHS specialist services or private options. Use our free BMI calculator above to check your current BMI as a starting point.
What if I don't qualify for prescription weight loss medication yet?
The NHS offers tier 1 and 2 weight loss support including digital tools, behaviour change programmes, and community weight management services. Our free weight loss calculator and progress tracker can help you track your weight management journey. Your GP can refer you to local services and discuss the best approach for your health goals.
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.