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
Are Protein Shakes Good for Weight Loss?
Protein shakes can be a useful tool for weight management when combined with a healthy diet and physical activity. However, if you're struggling with weight loss through dietary changes alone, prescription weight management medications are available in the UK. This guide explains how protein shakes fit into a weight loss plan, plus information about medication options for eligible adults and how to discuss them with your GP.
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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
If you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions, you may be eligible for prescription weight management medication in the UK. Three main options are currently licensed:
- Mounjaro (tirzepatide) — a once-weekly GLP-1 and GIP receptor agonist injection. Clinical trials showed participants lost an average of 15–21% of their body weight alongside a reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a once-weekly GLP-1 receptor agonist injection. Research demonstrated approximately 15% average weight loss in clinical studies.
- Saxenda (liraglutide) — a daily GLP-1 injection, an alternative if weekly injections aren't suitable.
These are prescription-only medicines requiring clinical assessment from a healthcare professional. Our free GLP-1 weight loss calculator can help you estimate potential results at different doses, though individual outcomes vary significantly.
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 in the UK
NHS access: Available through specialist tier 3 weight management services. You'll need a GP referral, and services vary by region. Waiting lists can be lengthy in some areas.
Private access: Available through online consultations with UK-licensed prescribers, followed by dispensing via a GPhC-registered pharmacy. No NHS referral needed, though costs typically range from £129–£320 monthly depending on dose.
Either route requires a clinical assessment to confirm eligibility and suitability. Your GP can discuss which option is appropriate for you and whether medication alongside lifestyle changes would help with weight management uk goals. Remember, protein shakes work best when combined with overall dietary changes, not as a substitute for them.
- 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 protein shakes help you lose weight?
Protein shakes can support weight loss by increasing feelings of fullness, reducing calorie intake, and preserving muscle during weight loss. However, they're most effective alongside a reduced-calorie diet and physical activity. Individual results vary, and shakes alone won't clinically studied weight loss without overall dietary changes.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are prescription injections used for weight management in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist with clinical trial results showing 15–21% average weight loss. Wegovy (semaglutide) is a GLP-1 agonist showing approximately 15% average weight loss. Results vary individually, and a prescriber will assess which is suitable for you.
Can I get weight loss medication on the NHS?
Yes. Weight loss medication is available through NHS specialist tier 3 weight management services for eligible adults. You'll need a GP referral. Access and waiting times vary significantly by region. Your GP can advise whether you qualify and how to access services in your area.
How do I know if I'm eligible for prescription weight loss medication?
You may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with at least one weight-related health condition (such as type 2 diabetes, high blood pressure, or sleep apnoea). Use our free BMI calculator to check your BMI, then discuss eligibility with your GP or a licensed prescriber.
Is prescription weight loss medication safe in the UK?
Mounjaro and Wegovy are approved by the MHRA for weight management in UK adults. All medications have potential side effects — nausea and diarrhoea are common initially. A healthcare professional will assess whether the medication is safe for you based on your medical history before prescribing. Always report any concerns to your prescriber.
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.