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
Do Herbal Weight Loss Pills Actually Work?
Herbal weight loss pills are popular in the UK, but evidence for their effectiveness is limited. Most herbal supplements lack robust clinical trials, and results vary widely between individuals. While some ingredients like green tea extract and caffeine have modest research support, prescription weight loss medication and lifestyle changes remain the most evidence-based approaches to sustainable weight management. This guide explains what the science shows about herbal pills and your other options.
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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.
What Does Research Say About Herbal Weight Loss Pills?
Most herbal weight loss pills contain a mix of plant-based ingredients claimed to boost metabolism or reduce appetite. Common ingredients include green tea extract, caffeine, conjugated linoleic acid (CLA), and various herbal blends. However, the evidence is mixed:
- Green tea extract may support modest weight loss (typically 1–3 kg over 12 weeks) when combined with diet and exercise
- Caffeine can increase energy expenditure temporarily, but tolerance develops quickly
- Most multi-ingredient herbal supplements lack large-scale clinical trials proving efficacy
- Results vary dramatically between individuals — what works for one person may not work for another
- Herbal pills are not regulated as strictly as prescription medications in the UK, so quality and potency vary between brands
The NHS notes that herbal supplements alone are unlikely to produce significant weight loss without dietary changes and increased physical activity.
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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.
How Do Herbal Pills Compare to Evidence-Based Weight Loss Options?
If you're exploring weight management in the UK, you have several evidence-based options beyond herbal pills. Prescription weight loss medication like Mounjaro (tirzepatide) and Wegovy (semaglutide) have strong clinical trial data showing average weight loss of 15–21% of body weight. These are GLP-1 medications that reduce appetite and support feeling fuller. NHS weight loss services also offer structured diet and behaviour change programmes, which have proven long-term success. You can calculate your BMI using our free tool and discuss prescription options with your GP or a weight management specialist. Remember, sustainable weight loss requires a calorie deficit alongside lifestyle changes — no pill, herbal or otherwise, replaces the fundamentals of eating fewer calories and moving more.
- 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.
Are herbal weight loss pills safe?
Most herbal weight loss pills are safe for short-term use in healthy adults, but they can interact with medications, cause digestive upset, or trigger palpitations (especially high-caffeine products). Always inform your GP if you're taking herbal supplements, particularly if you have diabetes, heart conditions, or are on other medicines. Quality varies by brand since herbal products aren't as strictly regulated as prescription medications in the UK.
How much weight can you lose with herbal pills?
Research shows herbal supplements typically produce modest results — often 1–3 kg over 12 weeks when combined with diet and exercise. Individual results vary significantly. Herbal pills alone, without calorie reduction and physical activity, usually produce little to no weight loss. This is why prescription weight loss medication combined with lifestyle changes remains more effective.
Can I use herbal pills alongside prescription weight loss medication?
Not advisable without medical guidance. Combining herbal supplements with prescription medications like Mounjaro or Wegovy increases the risk of side effects, nutrient interactions, and unpredictable results. Always discuss any supplements with the prescriber managing your weight loss medication before adding herbal pills.
What's the difference between herbal pills and GLP-1 injections?
Herbal pills are unregulated supplements with limited evidence. GLP-1 medications like Wegovy are prescription-only with robust clinical trials showing 15% average weight loss. GLP-1 medications have MHRA and UK approval; herbal supplements do not. Results are more predictable and sustainable with prescription medication alongside dietary and lifestyle changes.
Will my GP prescribe weight loss medication instead of herbal pills?
Your GP can refer you to NHS weight management services if you have a BMI of 30 or above, or 27+ with weight-related health conditions. Prescription options like Mounjaro and Wegovy are evidence-based and more effective than herbal alternatives. Use our free GLP-1 weight loss calculator to estimate potential results, then discuss prescription options with your GP or specialist.
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.