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 Morning Drink For Weight Loss — What Actually Works in the UK
While popular morning drinks like green tea or lemon water have minimal direct weight loss effects, sustainable weight management in the UK typically requires a comprehensive approach. For many adults struggling with excess weight, prescription weight loss medications like Mounjaro and Wegovy offer clinically proven support when combined with dietary changes and physical activity. If you're looking to lose weight effectively, understanding all available options—from lifestyle changes to prescription treatments—is essential. Our free GLP-1 weight loss calculator can help you explore potential outcomes if you're eligible for medication-based support.
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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 Management Options Available in the UK
Three prescription medications are currently licensed in the UK for weight management:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of their body weight at the highest dose, alongside dietary changes and increased physical activity.
- Wegovy (semaglutide) — A GLP-1 receptor agonist. Evidence from clinical trials demonstrated average weight loss of approximately 15% of body weight at the maximum dose.
- Saxenda (liraglutide) — A daily GLP-1 injection. Clinical data supports modest but sustainable weight loss results.
All three are prescription-only medicines that require a clinical assessment before being prescribed. They work by helping regulate appetite and supporting feeling fuller after meals—far more effective than any morning drink alone. Individual results vary significantly based on adherence, diet, and lifestyle factors. Use our free BMI calculator to check your current weight category and determine whether you might be eligible for prescription weight management support.
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 Access and Next Steps
In the UK, prescription weight loss medications are accessed through two routes:
- NHS route: Through specialist tier 3 weight management services via your GP referral. Availability varies by region, and waiting times can be lengthy in many areas.
- Private route: Through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. Available without NHS referral but involves private costs.
To find out if you're eligible, speak with your GP about your weight management goals. You'll typically need 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. Your GP can discuss prescription weight loss medication with you as part of your personalised weight management plan. Track your progress with our free progress tracker once you've started any weight loss programme.
- 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 morning drinks like green tea actually help with weight loss?
Green tea and similar drinks contain caffeine and antioxidants, which may have minor metabolic effects. However, the weight loss impact is minimal—typically less than 0.5 kg per year. Sustainable weight loss requires a calorie deficit through diet and activity. For significant results, most people need structured approaches or prescription support.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 medication, while Wegovy (semaglutide) is a GLP-1-only medication. Clinical trials showed Mounjaro achieved slightly higher average weight loss (15–21%) compared to Wegovy (15%). Both are once-weekly injections. Your GP or prescriber will assess which is appropriate for you based on individual health factors.
Am I eligible for prescription weight loss medication on the NHS?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. Access is through NHS specialist weight management services (tier 3) via your GP referral. Availability varies significantly by region, and waiting lists can be long. Your GP can advise on your eligibility.
How quickly will I lose weight on prescription medication?
The NHS recommends losing 0.5–1 kg per week for sustainable weight loss. Clinical trial participants on GLP-1 medications lost varying amounts depending on dose and adherence. Weight loss is not assured and varies between individuals. Most people see gradual progress over 12–20 weeks as doses are increased. Medication works best alongside dietary changes and physical activity.
Can I get prescription weight loss medication privately in the UK?
Yes. Prescription weight loss medications are available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. You don't need an NHS referral. Costs vary by dose and provider (approximately £129–£320 per month). Any prescriber will assess your medical history and suitability before issuing a prescription.
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.