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 loss when part of a reduced-calorie diet, as they help preserve muscle mass and increase satiety. However, they work best alongside other strategies. If you're looking for additional support with weight management in the UK, prescription medications are available for eligible adults. Our free GLP-1 weight loss calculator can help you explore what weight loss medication options might project for different doses. Combined with lifestyle changes, these tools offer a comprehensive approach to sustainable weight loss.
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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.
Protein Shakes and Weight Loss — The Evidence
Protein shakes can support weight loss in several ways. Protein increases satiety, meaning you feel fuller for longer, which may reduce overall calorie intake. Studies show that higher protein intake helps preserve muscle mass during weight loss, which is important because muscle tissue burns more calories at rest than fat tissue.
- A high-protein diet (around 1.6–2.2g protein per kg body weight) combined with calorie restriction and exercise is associated with greater fat loss than lower-protein diets
- Protein shakes offer convenience and portion control, making it easier to track calories
- They can replace high-calorie meals or snacks if chosen carefully
However, protein shakes alone do not cause weight loss. You still need a calorie deficit. Some commercial shakes contain added sugars and calories that may undermine weight loss efforts. Choose shakes with minimal added sugar, at least 20g protein, and fewer than 200 calories per serving. Combined with our free BMI calculator, you can monitor your progress and see where your weight sits on the NHS health scale as you make dietary changes.
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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.
Weight Loss Medication in the UK — Beyond Shakes
For adults struggling to lose weight through lifestyle changes alone, prescription weight loss medication is available in the UK. The most commonly prescribed options are Mounjaro (tirzepatide) and Wegovy (semaglutide) — both are GLP-1 receptor agonist injections that work by reducing appetite and supporting feelings of fullness.
Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. South Asian, Chinese, Black African, or Black Caribbean adults may have access at lower BMI thresholds. Access through the NHS requires referral to a specialist weight management service, though waiting lists vary significantly by region. Private prescribing is also available through licensed online services. In clinical trials, these medications supported an average weight loss of 15–21% of body weight when combined with lifestyle changes. Use our GLP-1 weight loss calculator to estimate 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.
Do protein shakes alone help you lose weight?
No, protein shakes alone do not cause weight loss. Weight loss requires a calorie deficit. Protein shakes are a tool to help you achieve that deficit by increasing fullness and making meals easier to track. They work best alongside a balanced diet and physical activity.
What should I look for in a weight loss protein shake?
Choose shakes with at least 20g protein, fewer than 200 calories per serving, and minimal added sugar (less than 5g per serving). Avoid high-sugar drinks marketed as "weight loss shakes" — they may provide calories without supporting satiety.
Can I get prescription weight loss medication on the NHS in the UK?
Yes, if you meet the eligibility criteria (BMI 30 or above, or 27 with weight-related health conditions). You'll need to discuss this with your GP, who can refer you to a specialist tier 3 weight management service. Availability and waiting times vary significantly by region.
What is the difference between Mounjaro and Wegovy for weight loss UK?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Both are once-weekly injections available in the UK. Clinical trials suggest Mounjaro may support slightly greater average weight loss, but individual results vary. Your prescriber will assess which is appropriate for you.
Should I use protein shakes if I'm taking weight loss medication like Mounjaro?
Yes, protein shakes can still be useful alongside prescription weight loss medication. These medications work best when combined with dietary changes and increased physical activity. Protein shakes help preserve muscle during weight loss and support your reduced-calorie diet. Always discuss dietary choices with 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.