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
Protein Shakes for Weight Loss — Prescription Alternatives Available
Protein shakes can be a useful tool for meal replacement and reducing calorie intake, but for many UK adults, prescription weight management medications offer more substantial results. If you're considering protein shakes as part of a weight loss plan, it's worth understanding what prescription options are available through the NHS or private prescribing. This guide explains how protein shakes fit into a weight loss strategy and when medication might be appropriate for your situation.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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-Licensed Prescription Weight Loss Medications
If you're eligible, prescription weight management medications may provide more significant support than meal replacements alone. The main options available in the UK are:
- Mounjaro (tirzepatide) — A once-weekly injection that works by activating two natural hormone pathways. 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 injection. In clinical trials, it helped participants lose approximately 15% of body weight on average.
- Saxenda (liraglutide) — A daily GLP-1 injection with similar mechanisms to Wegovy, though requiring more frequent injections.
All three are prescription-only medicines requiring a clinical assessment. Individual results vary considerably. These medications are typically used alongside dietary changes and physical activity, not as replacements 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.
Eligibility and How to Access Treatment in the UK
You may be eligible for prescription weight loss medication if you have a BMI of 30 or above, or 27 or above with a weight-related health condition such as type 2 diabetes, high blood pressure, or cardiovascular disease. Eligibility criteria vary slightly for adults of South Asian, Chinese, Black African, or Black Caribbean heritage—your GP can assess this.
NHS access: Referral to a specialist tier 3 weight management service, though waiting times vary by region. Private access: Online consultation with a UK-licensed prescriber. Start by speaking with your GP about whether prescription medication is appropriate for you, or explore private prescribing options if you prefer a faster route. Try our free BMI calculator above to check where you fall on the weight classification scale, and use our GLP-1 weight loss calculator to see potential outcomes at different doses.
- 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 protein shakes alone help me lose weight?
Protein shakes can contribute to weight loss by reducing overall calorie intake and helping you feel fuller longer. However, they work best as part of a broader approach including a balanced diet and physical activity. For more significant results, prescription medications like Mounjaro or Wegovy may be appropriate depending on your BMI and health profile.
What's the difference between Mounjaro and Wegovy?
Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy is a GLP-1 agonist only. Clinical trials showed Mounjaro produced slightly higher average weight loss (15–21% vs approximately 15%), but results vary individually. Your prescriber will assess which is most suitable for you based on your health needs.
How do I find out if I'm eligible for prescription weight loss medication?
Start by speaking with your GP, who can assess your BMI, health conditions, and medical history. On the NHS, you may be referred to a specialist weight management service. Privately, you can have an online consultation with a UK-licensed prescriber. Use our free BMI calculator to understand your current classification before speaking with your healthcare provider.
Is weight loss medication available on the NHS?
Yes, NICE has approved tirzepatide (Mounjaro) and semaglutide (Wegovy) for use within NHS specialist weight management services. However, access varies significantly by region and availability. Waiting lists can be lengthy. Private prescribing offers faster access but involves costs, typically £150–£320 per month depending on dose.
How much weight can I expect to lose with prescription medication?
Clinical trials showed average weight loss of 15–21% of body weight with Mounjaro and approximately 15% with Wegovy, achieved alongside reduced-calorie diet and increased physical activity. However, individual results vary significantly—some people lose more, others less. Results are not assured, and medication is always used alongside lifestyle changes, not instead of them.
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.