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
Is Berberine Good For Weight Loss?
Berberine is a plant-derived compound often marketed for weight loss, but evidence for its effectiveness in humans remains limited. If you're looking to lose weight and wondering whether berberine or other supplements might help, it's worth understanding what the research actually shows — and what medically-proven alternatives are available in the UK. Many people interested in weight management ask about supplements first, but prescription weight loss medication offers stronger clinical evidence. Our free BMI calculator can help you check where you currently stand, and this guide will explore both supplement claims and NHS-approved options available to eligible adults.
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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.
Berberine and Weight Loss: What the Evidence Shows
Berberine is an alkaloid compound found in plants like barberry and goldenseal. Laboratory and animal studies suggest it may affect metabolism and glucose control, which has led to interest in weight management claims. However, human evidence is very limited. A small number of clinical trials in humans show modest effects on weight and blood sugar, but sample sizes are tiny and results are far from conclusive.
- Most berberine studies involved small participant groups (under 100 people)
- Weight loss observed was typically modest — around 2–4 kg over 12 weeks
- Quality of evidence is rated as low by healthcare standards
- Long-term safety and effectiveness remain unclear
In contrast, prescription weight loss medication used for weight management in the UK — including Mounjaro (tirzepatide) and Wegovy (semaglutide) — have undergone rigorous clinical trials with thousands of participants. These medications showed average weight loss of 15–21% of body weight, making them significantly more effective than berberine supplements. If you're eligible, prescription options offer evidence-based support rather than speculative supplement effects.
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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.
UK Prescription Weight Loss: A Clinically-Proven Alternative
If you have a BMI of 30 or above, or a BMI of 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure, you may be eligible for prescription weight loss medication in the UK. This includes GLP-1 receptor agonist injections and dual GIP/GLP-1 agonists that are licensed and regulated by the MHRA.
Access is available through two routes: NHS specialist weight management services (though waiting lists can be lengthy in many regions) or through private online prescribing following a clinical assessment by a UK-licensed healthcare professional. Your GP can discuss your options and assess whether prescription weight loss medication is appropriate for you. Use our GLP-1 weight loss calculator to explore potential outcomes, and our weight converter to understand your current weight in different units for NHS comparisons.
- 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.
Does berberine actually help with weight loss?
Limited human evidence exists. Small studies show modest weight loss (2–4 kg), but sample sizes are tiny and long-term effects are unknown. Prescription weight loss medications available in the UK have far stronger clinical evidence — showing 15–21% average weight loss — making them more reliably effective.
Is berberine safe to take for weight loss?
Berberine is generally well-tolerated in short-term studies, though gastrointestinal side effects are common. However, it may interact with certain medications and isn't regulated as strictly as prescription medicines. Always inform your GP if you're considering berberine alongside other treatments.
What prescription weight loss options are available on the NHS in the UK?
NHS weight management services may prescribe Mounjaro (tirzepatide), Wegovy (semaglutide), or Saxenda (liraglutide) for eligible adults. Eligibility requires a BMI of 30+ or 27+ with weight-related health conditions. Access is through specialist tier 3 services via GP referral, though availability varies by region.
How effective is prescription weight loss medication compared to supplements?
Prescription medications like Mounjaro showed 15–21% average weight loss in clinical trials with thousands of participants. Berberine showed only 2–4 kg loss in small studies. If you're eligible for prescription medication, the clinical evidence strongly favours it over supplements for sustained weight loss.
How do I find out if I'm eligible for prescription weight loss medication in the UK?
Start by checking your BMI using our free BMI calculator. If your BMI is 30+ or 27+ with weight-related conditions, speak to your GP about referral to specialist weight management services, or explore private online prescribing options with a UK-licensed healthcare provider.
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.