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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Protein Milk Shake for Weight Loss in the UK
Protein milk shakes can be a useful tool to support weight loss when part of a reduced-calorie diet, but many people find prescription weight management medication offers more significant results. If you're interested in weight loss support in the UK, there are several evidence-based options available — from dietary approaches to GLP-1 weight loss injections. This guide explains how protein shakes fit into a weight management strategy, and what NHS-approved prescription options are available if you're eligible. Calculate your BMI using our free tool above to understand your current health range.
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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.
Prescription Weight Loss Options Available in the UK
If you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions (such as type 2 diabetes, high blood pressure, or cardiovascular disease), you may be eligible for prescription weight management medication in the UK.
Three main options are currently licensed:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist injection, once weekly. Clinical trials showed average weight loss of 15–21% of body weight alongside dietary changes.
- Wegovy (semaglutide) — a GLP-1 receptor agonist injection, once weekly. Evidence from clinical trials demonstrated average weight loss of approximately 15% of body weight.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, injected daily. Available through NHS specialist services and private prescribing.
These are prescription-only medicines. Each requires a clinical assessment to determine if it's suitable for you. Individual results vary significantly, and medication works best alongside a reduced-calorie diet and increased physical activity.
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 Access vs Private Prescribing — How to Get Started
In the UK, prescription weight loss medication can be accessed through two routes:
- NHS specialist services (Tier 3/4): Referral from your GP to a regional weight management service. Availability varies by area, and waiting lists can be several months.
- Private online prescribing: Consultation with a UK-licensed prescriber through GPhC-registered services. Available without NHS referral, typically faster access, but costs apply (approximately £129–£320 per month depending on dose).
Your first step is a conversation with your GP about whether prescription weight management options are appropriate for you. They can assess your BMI, health conditions, and medications to provide personalised advice. Our free GLP-1 weight loss calculator can help you understand potential outcomes, and our progress tracker lets you monitor your weight loss journey over time.
- 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 support weight loss as part of a calorie-controlled diet — they help you feel fuller longer and preserve muscle during weight loss. However, they work best combined with overall dietary changes and physical activity. If you've tried diet and exercise without sufficient results, your GP can assess whether prescription medication might help.
What is the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials suggest Mounjaro may produce slightly higher average weight loss (15–21% vs 15%), but individual results vary. Both are prescription-only and require a clinical assessment. Your prescriber will recommend the most suitable option for you.
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 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 apply. Your GP can assess your eligibility.
How quickly will I lose weight on Mounjaro or Wegovy?
The NHS recommends a safe weight loss rate of 0.5–1 kg per week. Clinical trials showed that people using these medications alongside a reduced-calorie diet and physical activity achieved average weight loss of 15–21% over several months. Individual results vary — some people lose more, others less. Consistent effort with diet and exercise is essential.
Can I get prescription weight loss medication privately if I don't qualify for the NHS?
Yes. Private GPhC-registered online pharmacies can prescribe Mounjaro, Wegovy, and Saxenda following an online clinical assessment. You do not need an NHS referral. However, you must still meet clinical eligibility criteria — a prescriber will assess your BMI, health conditions, and medications before issuing a prescription.
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.