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
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Yerba Mate and Weight Loss — What Works in the UK
Yerba mate is a herbal beverage with caffeine that some people believe supports weight management. However, scientific evidence shows it provides only modest support for weight loss on its own. If you're looking for effective weight management in the UK, prescription medications like Mounjaro and Wegovy have strong clinical evidence and are available through NHS specialist services or private prescription. This guide explains your options and how to find out if you're eligible for evidence-based treatment.
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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
For adults seeking effective weight management in the UK, several prescription weight loss medications are available with proven clinical evidence. These work differently from herbal supplements like yerba mate:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist. In clinical trials, participants lost an average of 15–21% of their body weight over 72 weeks, alongside a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a GLP-1 receptor agonist. Clinical trials showed average weight loss of approximately 15% body weight at the maximum dose.
- Saxenda (liraglutide) — a GLP-1 agonist given as a daily injection. Evidence supports modest but sustained weight loss with consistent use.
All three are prescription-only medicines available in the UK for eligible adults. Unlike yerba mate, they work by reducing appetite and helping you feel fuller after eating.
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.
Getting Started — NHS vs Private Access
To access weight loss medication in the UK, you have two main routes. NHS access is through your GP, who can refer you to a tier 3 specialist weight management service — though waiting lists vary significantly by region. Private access is available through online consultations with UK-licensed prescribers, without requiring an NHS referral.
To find out if you're eligible, your weight and health are assessed using BMI and other health factors. Adults with a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure, may qualify. Use our free BMI calculator to check your personal BMI, and speak to your GP about your weight loss medication options.
- 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 yerba mate actually help with weight loss?
Yerba mate contains caffeine which may slightly increase alertness and energy expenditure, but scientific evidence shows it produces minimal weight loss on its own — typically less than 1 kg over several weeks. For significant, sustained weight loss, prescription medications or lifestyle changes are much more effective.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro is a dual GIP and GLP-1 receptor agonist, whilst Wegovy is a GLP-1 agonist only. Both are once-weekly injections, but Mounjaro typically produces slightly greater average weight loss (15–21% vs approximately 15%). Individual results vary, and your prescriber will recommend the most suitable option for you.
Can I get prescription weight loss medication on the NHS?
Yes, if you meet eligibility criteria (BMI 30+, or 27+ with health conditions), you can be referred to an NHS specialist weight management service. However, waiting lists vary significantly by region. Your GP can assess your eligibility and discuss both NHS and private options available to you.
How do I know if I'm eligible for weight loss medication?
Eligibility depends on your BMI and overall health. Use our free BMI calculator to check your BMI — if it's 30 or above, or 27–29.9 with conditions like high blood pressure or type 2 diabetes, you may qualify. Your GP or a licensed prescriber can assess your individual situation and confirm eligibility.
Is prescription weight loss medication better than supplements like yerba mate?
Prescription medications like Mounjaro and Wegovy have robust clinical trial evidence showing significant average weight loss of 15–21% body weight. Supplements like yerba mate have minimal evidence for weight loss. Prescription medications are more effective, but they're prescription-only and require clinical assessment to ensure they're safe and appropriate for you.
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.