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
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Best Protein Shakes For Weight Loss UK
Protein shakes are popular for supporting weight loss through increased satiety and muscle preservation during calorie restriction. However, they work best alongside a reduced-calorie diet and physical activity. For adults struggling with weight management in the UK, prescription medications are also available through the NHS or private prescribing. This guide explores protein shake options and explains when prescription weight loss medication may be worth discussing with your GP as part of a comprehensive weight management strategy.
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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.
Protein Shakes vs Prescription Weight Management Options
Protein shakes can support weight loss by helping you feel fuller for longer and preserving muscle mass during a calorie deficit. The NHS recommends losing weight at a rate of 0.5 to 1 kg per week, which typically requires a calorie deficit of around 500 kcal per day.
However, for many people, diet and exercise alone aren't sufficient. If you have a BMI of 30 or above, or 27 or above with weight-related health conditions (such as type 2 diabetes, high blood pressure, or sleep apnoea), you may be eligible for prescription weight loss medication in the UK.
- Mounjaro (tirzepatide) — a once-weekly injection that works as a dual GIP and GLP-1 receptor agonist. Clinical trials showed participants lost an average of 15–21% of their body weight.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical trials showed average weight loss of around 15% of body weight.
- Saxenda (liraglutide) — a daily GLP-1 injection, less commonly prescribed than the weekly options.
These are prescription-only medicines available through NHS specialist weight management services or private prescribing following a clinical assessment.
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 access: Weight loss medications are available through tier 3 specialist weight management services. Your GP can refer you, though waiting lists vary significantly by region and can be lengthy in many areas.
Private access: Available through GPhC-registered online pharmacies with a UK-licensed prescriber assessment. This is often faster but involves a private cost.
Start by calculating your BMI using our free BMI calculator to see if you fall within the eligible range. If you do, speak to your GP about your options — whether protein shakes, lifestyle changes, prescription medication, or a combination approach. Your prescriber will assess what's right for your individual health and circumstances.
- 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.
Are protein shakes alone enough for weight loss?
Protein shakes can support weight loss by increasing satiety and preserving muscle, but they work best as part of a reduced-calorie diet and regular physical activity. For sustainable results, the NHS recommends losing 0.5–1 kg per week. If you're struggling despite diet and exercise, prescription weight loss medication may be an option worth discussing with your GP.
Who is eligible for prescription weight loss medication in the UK?
Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, etc.) may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at slightly lower BMI thresholds due to higher cardiovascular risk. Your GP or prescriber will assess individual eligibility.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), while Wegovy (semaglutide) activates one (GLP-1 only). In clinical trials, Mounjaro showed slightly higher average weight loss (15–21%) compared to Wegovy (around 15%). Both are once-weekly injections. Individual results vary significantly.
Can I get prescription weight loss medication on the NHS?
Yes. Mounjaro and Wegovy are available through NHS tier 3 specialist weight management services. Access varies by region and waiting lists can be long. Your GP can refer you if you meet eligibility criteria. Private prescribing is also available without NHS referral, though this involves private costs.
How do I know if prescription weight loss medication is right for me?
Start by calculating your BMI using our free BMI calculator to check your eligibility range. Then speak to your GP, who can assess your individual health, weight history, and any weight-related conditions. A prescriber will determine whether medication is appropriate for you alongside lifestyle changes.
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.