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
Weight Loss Berberine — What UK Adults Should Know
Berberine is a plant compound that has attracted interest for potential weight management benefits, but it's not licensed as a weight loss treatment in the UK. If you're looking for evidence-based weight management support, the NHS and private healthcare in the UK offer several prescription options. This guide covers what berberine is, what the evidence shows, and the prescription weight management options available to eligible adults in the UK today.
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.
UK-Licensed Prescription Weight Loss Options
If you're exploring weight management UK options, several prescription medications are available for eligible adults:
- Mounjaro (tirzepatide) — a once-weekly GLP-1 injection shown to help participants lose an average of 15–21% of body weight in clinical trials
- Wegovy (semaglutide) — a once-weekly GLP-1 injection, with clinical trial data showing approximately 15% average weight loss
- Saxenda (liraglutide) — a daily GLP-1 injection offering similar weight loss support
These are prescription weight loss medications requiring clinical assessment. Eligibility typically includes a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses, or use our BMI calculator to understand your current weight category.
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.
NHS vs Private Access — How to Get Started
NHS route: Speak to your GP about referral to a specialist weight management service (tier 3). NHS availability varies significantly by region, and waiting lists can be lengthy.
Private route: Online consultations with UK-licensed prescribers are available without NHS referral. A clinical assessment determines eligibility, and prescriptions are dispensed by GPhC-registered pharmacies.
Regardless of route, nhs weight loss guidance emphasises sustainable loss of 0.5–1 kg per week alongside dietary changes and increased physical activity. Use our progress tracker to log your weight loss journey once you've begun treatment.
Q1: Is berberine approved for weight loss in the UK? A1: No, berberine is not licensed as a weight loss medication in the UK. While some research suggests modest metabolic effects, it lacks the clinical evidence and regulatory approval of prescription options like Mounjaro or Wegovy. For clinically-proven weight management, speak to your GP about eligible prescription treatments. Q2: What is the evidence for berberine and weight loss? A2: Some studies show berberine may have mild effects on blood sugar and metabolism, but evidence is limited compared to GLP-1 medications. UK healthcare providers prioritise treatments with robust clinical trial data. Prescription options have demonstrated clear, measurable weight loss outcomes in large trials. Q3: Who is eligible for prescription weight loss medication in the UK? A3: Adults with a BMI of 30 or above, or 27 or above with weight-related conditions (type 2 diabetes, high blood pressure, etc.) may be eligible. A GP or licensed prescriber assesses your individual circumstances. Use our BMI calculator to check your current BMI. Q4: How much weight can I lose with prescription weight loss injections? A4: Clinical trials show Mounjaro users lost 15–21% of body weight on average, while Wegovy users lost approximately 15%. Results vary significantly between individuals and depend on dose, diet, and activity level. These medications work alongside lifestyle changes, not instead of them. Q5: How do I find out if I'm eligible for prescription weight loss treatment? A5: Contact your GP to discuss your options and whether referral to an NHS specialist service is appropriate. Alternatively, private online prescribers offer consultations without NHS referral. Both routes include clinical assessment to determine suitability for your health profile.- 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.
What is BMI and how is it calculated?
BMI (Body Mass Index) is calculated by dividing your weight in kilograms by your height in metres squared. It's the standard screening tool used by the NHS to assess whether adults are a healthy weight.
Is BMI accurate for everyone?
BMI is a useful screening tool but doesn't account for muscle mass, bone density, or body fat distribution. Athletes may have a high BMI without excess fat. The NHS recommends using BMI alongside waist circumference for a more complete picture.
What are GLP-1 medications like Mounjaro and Wegovy?
GLP-1 receptor agonists are prescription medications that mimic gut hormones to reduce appetite and help with weight loss. Mounjaro (tirzepatide) and Wegovy (semaglutide) are the two most widely used for weight management in the UK.
Am I eligible for GLP-1 weight loss medication in the UK?
Generally, you need a BMI of 30+ (obese) or 27+ with a weight-related health condition. You must be 18 or over. Use our BMI calculator to check.
What is the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist with up to 22.5% weight loss. Wegovy (semaglutide) is GLP-1-only with up to 15-17% weight loss. Both are weekly injections.
Is this website free to use?
Yes, 100% free. No sign-up required. All tools work instantly in your browser and no personal data is stored on our servers.
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.