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
Best Tea for Detox Weight Loss โ UK Weight Management Options
While herbal teas like green tea and detox blends are popular, the scientific evidence for weight loss through tea alone is limited. If you're looking for weight management support in the UK, prescription options like Mounjaro and Wegovy offer clinically proven results for eligible adults. These GLP-1 medications work through different mechanisms than dietary supplements and may help you lose weight alongside lifestyle changes. Our GLP-1 weight loss calculator can help you understand potential outcomes if you're eligible for prescription treatment. Talk to your GP about which approach is right for your health goals.
10,000+ calculations today ยท NHS-aligned thresholds ยท 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/mยฒ).
While BMI isn't a perfect measure โ it doesn't account for muscle mass, bone density, or fat distribution โ 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 โ 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 Options Available in the UK
If you're interested in weight management through the UK's nhs weight loss services or private prescribing, several prescription weight loss medication options are available. The two most commonly prescribed are Mounjaro (tirzepatide) and Wegovy (semaglutide), both licensed for adults meeting specific eligibility criteria.
- Mounjaro โ a dual GIP and GLP-1 receptor agonist. Clinical trials showed average weight loss of 15โ21% body weight at maximum dose, though individual results vary.
- Wegovy โ a GLP-1 receptor agonist. Clinical evidence suggests average weight loss around 15% body weight alongside diet and physical activity.
- Saxenda (liraglutide) โ a daily GLP-1 injection, another option for eligible adults.
All three are prescription-only medicines requiring a clinical assessment from a licensed prescriber. Use our BMI calculator to check if you might be eligible based on your current weight and health profile.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care โ 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 โ 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 โ completely free.
NHS vs Private Access and Eligibility
NHS access: Through specialist tier 3 weight management services, typically after GP referral. Availability varies significantly by region and waiting lists can be lengthy.
Private access: Through online GPhC-registered pharmacies following a consultation with a UK-licensed prescriber. Often faster access but involves cost.
Eligibility basics: Adults with a BMI of 30 or above, or 27โ29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, heart disease history), may qualify. Lower thresholds apply for South Asian, Chinese, Black African, and Black Caribbean adults.
Your GP can assess your individual situation and discuss whether weight loss injections uk are appropriate for you. They can also advise on combining medication with diet, exercise, and our free progress tracker.
- 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 โ 5mg โ 7.5mg โ 10mg โ 12.5mg โ 15mg
- GLP-1 receptor agonist
- Up to 15โ17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg โ 0.5mg โ 1mg โ 1.7mg โ 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 | 15โ22.5% | 12โ17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20โ32 weeks | 16โ20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | ยฃ150โยฃ250/month | ยฃ150โยฃ300/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 โ 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.
Is herbal tea effective for weight loss?
Herbal teas like green tea contain compounds that may modestly boost metabolism, but evidence for significant weight loss is limited. A healthy diet, physical activity, and addressing overall calorie intake remain the foundation for weight management. Prescription medications offer more substantial clinical support if you're eligible.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections for weight management. Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), whilst Wegovy (semaglutide) activates GLP-1 alone. Clinical trials showed Mounjaro achieved slightly higher average weight loss (15โ21%) compared to Wegovy (around 15%), though individual results vary significantly.
Who is eligible for prescription weight loss medication in the UK?
Adults with a BMI of 30 or above, or BMI 27โ29.9 with weight-related health conditions (diabetes, high blood pressure, heart disease), may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds. A prescriber will assess your personal eligibility through clinical consultation.
Can I get weight loss medication through the NHS?
Yes, through NHS specialist weight management services (tier 3). Your GP can refer you, but access and waiting times vary by region. Private prescribing through online services may offer faster access. Either route requires a clinical assessment confirming you meet eligibility criteria.
Should I stop using supplements if I start prescription weight loss medication?
Always discuss with your prescriber before taking supplements alongside prescription weight loss medication. Some supplements may interact with GLP-1 medications or affect medication absorption. Your GP or prescriber can advise which supplements are safe to continue or should be paused during treatment.
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.