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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Weight Loss Tea That Works Fast — What Really Works in the UK
Weight loss teas are popular, but the evidence for fast results is limited. If you're looking for medically proven weight management, prescription medications like Mounjaro and Wegovy are available in the UK and have strong clinical evidence behind them. This guide explains the difference between weight loss supplements and prescription options, who is eligible, and how to explore treatments through the NHS or private prescribing. Understanding what actually works can help you make an informed choice about your weight management journey.
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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 Medications
If you're seeking weight management in the UK, prescription medications offer evidence-based alternatives to unproven teas and supplements. Three medications are licensed for weight loss:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 injection, once weekly, average weight loss of 15–21% body weight in clinical trials
- Wegovy (semaglutide) — a GLP-1 injection, once weekly, average weight loss around 15% body weight
- Saxenda (liraglutide) — a GLP-1 injection, once daily, effective for weight loss medication in eligible adults
These are prescription weight loss options requiring a clinical assessment. Use our free GLP-1 weight loss calculator to estimate potential results at different doses. Eligibility includes adults with a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease.
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: How to Access Weight Loss Treatment
NHS access to weight loss medication is through specialist tier 3 weight management services, typically via GP referral. Availability varies significantly by region and waiting times can be lengthy. Private access is available through online consultations with UK-licensed prescribers, with prescriptions dispensed by GPhC-registered pharmacies — no NHS referral required.
To find out if you're eligible, calculate your BMI using our free BMI calculator on this page. If your BMI is 30 or above (or 27+ with health conditions), contact your GP to discuss NHS weight loss options, or explore private prescribing if you prefer faster access. A qualified prescriber will assess your individual circumstances and medical history before recommending treatment.
- 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 weight loss tea actually work?
Most weight loss teas lack strong clinical evidence for significant weight loss. Some ingredients like green tea may offer modest metabolism support, but results are typically minimal compared to prescription medications. If you're seeking proven, fast-acting weight management, prescription options have robust clinical trial data behind them.
What's the difference between weight loss teas and prescription medication?
Weight loss teas are supplements with limited regulatory oversight and weak evidence. Prescription medications like Mounjaro and Wegovy are approved by the MHRA, have undergone rigorous clinical trials, and deliver measurable weight loss results (15–21% body weight). Prescription options require clinical assessment and GP guidance.
Who can get weight loss injections on the NHS in the UK?
Adults with a BMI of 30 or above, or 27 or above with weight-related health conditions, may be eligible through NHS specialist weight management services. Eligibility is assessed by your GP or specialist service. Regional availability varies, so ask your GP about local tier 3 weight management services.
How fast do prescription weight loss medications work?
Weight loss typically becomes noticeable within 4–8 weeks, with gradual progression over months. Most people lose 15–21% of body weight over 68–72 weeks (based on clinical trials). Results depend on dose, individual response, and adherence to diet and exercise alongside medication.
Can I get prescription weight loss medication without seeing my GP?
Yes, private online prescribers can assess and prescribe weight loss medication without NHS referral. You'll have a consultation with a UK-licensed prescriber who reviews your health history. However, your GP should be aware of any medication you're taking. NHS access requires GP involvement.
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.