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
Teas for Weight Loss — What Works in the UK
While certain teas like green tea and oolong may offer modest support for weight management, they work best alongside lifestyle changes. If you're looking for more substantial weight loss support, the UK has prescription options available. This guide covers both dietary approaches and clinically-proven weight management medication for eligible adults seeking professional help with weight loss in the UK.
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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.
Prescription Weight Loss Medication Available in the UK
For adults struggling with weight management, several prescription-only medications are licensed in the UK and may offer more significant support than dietary changes alone. These include Mounjaro (tirzepatide), a dual GIP/GLP-1 receptor agonist, and Wegovy (semaglutide), a GLP-1 agonist. Clinical trials show these medications may help achieve average weight losses of 15–21% of body weight alongside a reduced-calorie diet and physical activity.
Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. Use our free BMI calculator above to check if you fall within these ranges. These are prescription-only treatments requiring clinical assessment before dispensing.
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 Routes
In the UK, prescription weight loss medication is available through two routes. The NHS provides access via specialist tier 3 weight management services following a GP referral, though regional availability and waiting times vary considerably. Private online prescribing is also available through GPhC-registered pharmacies following a clinical consultation, without needing an NHS referral.
Your first step is a conversation with your GP, who can assess your individual health, discuss whether medication is appropriate, and explain both NHS and private options. They can refer you to specialist services or advise on private routes. Our GLP-1 weight loss calculator can help you explore projected outcomes with different treatment approaches before your appointment.
In the UK, prescription weight loss medication is available through two routes. The NHS provides access via specialist tier 3 weight management services following a GP referral, though regional availability and waiting times vary considerably. Private online prescribing is also available through GPhC-registered pharmacies following a clinical consultation, without needing an NHS referral.
Your first step is a conversation with your GP, who can assess your individual health, discuss whether medication is appropriate, and explain both NHS and private options. They can refer you to specialist services or advise on private routes. Our GLP-1 weight loss calculator can help you explore projected outcomes with different treatment approaches before your appointment.
- 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.
Do herbal teas really help with weight loss?
Some teas like green tea and oolong contain compounds that may offer modest metabolic support—approximately 2–3% increase in fat burning in some studies. However, effects are small and work best combined with calorie reduction and exercise. They're supportive additions but not replacements for lifestyle change or clinical treatment for significant weight loss.
What prescription weight loss options are available on the NHS in the UK?
Mounjaro (tirzepatide) and Wegovy (semaglutide) are both available through NHS specialist weight management services for eligible adults. Your GP can refer you to tier 3 services if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions. Availability varies by region and waiting times can be lengthy.
How do I know if I'm eligible for prescription weight loss medication?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with conditions like type 2 diabetes or high blood pressure. Use our BMI calculator above to check your status, then speak with your GP about your options. Ethnicity-adjusted thresholds apply for South Asian, Chinese, Black African, and Black Caribbean adults.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro is a dual GIP/GLP-1 receptor agonist that may support average weight loss of 15–21% of body weight, while Wegovy is a GLP-1 agonist supporting approximately 15% average loss. Both are once-weekly injections. Mounjaro escalates to higher maximum doses. Your prescriber will advise which is more suitable for your situation.
Can I access prescription weight loss medication privately in the UK?
Yes. Prescription weight loss medications are available through GPhC-registered online pharmacies following a clinical assessment by a UK-licensed prescriber. This route doesn't require an NHS referral and availability is typically faster than NHS services, though costs vary by medication and dose.
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.