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
Smoothie Drinks for Weight Loss — And When Medication Helps
Smoothie drinks can be part of a healthy weight loss plan, but their effectiveness depends on ingredients, portion size, and overall diet. For adults struggling with weight management in the UK, prescription options like Mounjaro and Wegovy offer clinically proven support. This guide covers both dietary approaches and the prescription weight loss medications available through NHS services and private prescribing. We'll help you understand which approach might suit your situation and how to start a conversation with your GP about what's right for you.
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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 Prescription Weight Loss Options for Eligible Adults
Three prescription-only weight loss injections are licensed in the UK:
- Mounjaro (tirzepatide) — dual GIP and GLP-1 receptor agonist. Once-weekly injection. In clinical trials, participants lost an average of 15–21% of body weight alongside diet and exercise changes.
- Wegovy (semaglutide) — GLP-1 receptor agonist. Once-weekly injection. Clinical trials showed average weight loss of approximately 15% of body weight.
- Saxenda (liraglutide) — GLP-1 receptor agonist. Daily injection. Average weight loss around 5–10% of body weight in trials.
You may be eligible if you have a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease. NHS weight loss medication is prescribed through specialist tier 3 services, though regional availability varies. Private prescribing is also available following an online clinical assessment. Individual results vary significantly — medication works best alongside dietary changes and increased physical activity, not as a substitute for lifestyle changes.
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
NHS route: Your GP can refer you to your local tier 3 weight management service, where specialists assess whether prescription medication is appropriate. Waiting times vary by region, sometimes extending several months.
Private route: GPhC-registered online pharmacies offer prescription assessments and dispensing without NHS referral. Costs typically range from £129–£320 per month depending on dose.
To find out if you're eligible, calculate your BMI using our free BMI calculator, then contact your GP to discuss weight loss support options. A prescriber can assess your individual health and help decide whether smoothies alone, medication, or a combination approach suits your needs best.
- 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.
Can smoothies help me lose weight?
Yes, smoothies can support weight loss if made with whole foods, protein, and controlled portions. Avoid sugary shop-bought smoothies — homemade versions with fruit, vegetables, Greek yoghurt, and nut butter are more filling. However, smoothies alone are unlikely to create the calorie deficit needed for sustained weight loss. They work best alongside dietary changes and increased physical activity.
Who can get prescription weight loss medication on the NHS in the UK?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions. You'll need a GP referral to a specialist tier 3 weight management service for assessment. Availability varies by region — ask your GP about services in your area or waiting times.
What's the difference between Mounjaro and Wegovy?
Both are once-weekly injections for weight management. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with average weight loss of 15–21% in trials. Wegovy (semaglutide) is a GLP-1 agonist alone with average weight loss around 15%. Both require prescription and clinical assessment. A prescriber can advise which is more suitable for your health profile.
How do I know if I'm eligible for weight loss medication?
You can check your BMI using our free GLP-1 weight loss calculator and BMI calculator on this page. If your BMI is 30 or above, or 27–29.9 with health conditions like diabetes or high blood pressure, you may be eligible. The next step is talking to your GP, who can refer you to specialist services or discuss private options with you.
Are smoothies enough, or do I need medication?
It depends on your individual situation. Smoothies can support weight loss as part of a balanced diet, but if you've struggled with diet and exercise alone, prescription medication may help. A GP or prescriber can assess your health, weight loss history, and comorbidities to recommend the best approach for you — which might be smoothies, medication, or a combination.
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.