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
Fat Burning Smoothie for Weight Loss — UK Guidance
Smoothies can be a helpful part of a balanced diet for weight management in the UK, but they work best alongside other lifestyle changes. If you're interested in additional support, prescription weight loss medications are now available through the NHS and privately for eligible adults. This guide covers both dietary approaches and medical options for effective weight management uk, helping you understand what might work 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.
Prescription Weight Loss Options Available in the UK
For adults seeking additional support beyond diet and exercise, three prescription weight loss medications are currently licensed in the UK: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 receptor agonist medications that work by helping regulate appetite and supporting feelings of fullness.
Clinical evidence: In clinical trials, these medications helped participants achieve average weight loss of 14–21% of body weight when combined with a reduced-calorie diet and increased physical activity. Individual results vary significantly depending on dose, genetics, and lifestyle factors.
- Mounjaro: 2.5–15 mg once weekly; dual GIP/GLP-1 mechanism
- Wegovy: 0.25–2.4 mg once weekly; GLP-1 mechanism
- Saxenda: 0.6–3 mg once daily; GLP-1 mechanism
All three are prescription-only medicines requiring clinical assessment before being prescribed. Try our free GLP-1 weight loss calculator to explore potential outcomes at different medication doses.
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 Eligibility and How to Access Weight Loss Support
You may be eligible for prescription weight loss treatment through the NHS if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply.
NHS access: Weight management medications are prescribed through specialist tier 3 services, typically requiring a GP referral. Availability and waiting times vary by region. Private access is available through GPhC-registered online prescribing services following a clinical assessment—no NHS referral needed. Use our free BMI calculator above to check your current BMI and discuss options with your GP to find out if you're eligible.
- 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 alone help me lose weight?
Smoothies can be part of a healthy weight loss plan when they fit into a calorie deficit, alongside regular physical activity and balanced meals. However, commercial smoothies can be high in sugar and calories, so homemade versions with whole fruits, vegetables, and protein are typically better for weight management. For significant weight loss, combining dietary changes with other support—including prescription medication if eligible—often produces better results.
What is a GLP-1 medication and how does it help with weight loss?
GLP-1 receptor agonist medications mimic a natural hormone that helps regulate appetite and blood sugar. They may help reduce cravings, support feeling fuller after smaller meals, and slow how quickly food leaves your stomach. Clinical trials show these medications can help achieve weight loss of 14–21% when combined with diet and exercise. Prescription weight loss medication nhs services now offer these options for eligible adults.
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. For some ethnic backgrounds (South Asian, Chinese, Black African, Black Caribbean), lower BMI thresholds apply. Contact your GP to discuss whether you qualify and ask for a referral to specialist weight management services in your area.
What's the difference between Mounjaro, Wegovy, and Saxenda?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 injection given once weekly. Wegovy (semaglutide) is a GLP-1 injection given once weekly. Saxenda (liraglutide) is a GLP-1 injection given once daily. All three require prescription and clinical assessment. Clinical evidence suggests Mounjaro may achieve slightly higher average weight loss, but individual results vary. Your prescriber will advise which is most suitable.
Can I get weight loss medication privately if I'm not eligible through the NHS?
Yes. Private prescribing through GPhC-registered online services is available for adults who don't meet NHS eligibility criteria or who prefer not to wait for NHS services. You'll need to complete an online clinical assessment with a UK-licensed prescriber, who will determine suitability. Costs vary but typically range from £129–£320 per month depending on medication and dose. Always ensure you use a registered prescriber and pharmacy.
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.