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
Do Protein Supplements Help With Weight Loss?
Protein supplements are widely used alongside weight management programmes in the UK, but the evidence shows they work best as part of a broader approach — not alone. Protein helps preserve muscle during weight loss, increases feelings of fullness, and supports recovery from physical activity. However, sustainable weight management requires a calorie deficit, increased physical activity, and often professional support. If you're considering weight loss medication like GLP-1 injections, protein intake becomes even more important to protect lean muscle mass during 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.
How Protein Supports Weight Loss Efforts
Protein's role in weight management: Protein has a higher thermic effect than carbohydrates or fat, meaning your body burns more calories digesting it. It also promotes satiety — helping you feel fuller for longer — which can reduce overall calorie intake.
- Preserves lean muscle during weight loss
- Increases feelings of fullness after meals
- Boosts metabolism slightly through digestion
- Supports recovery from exercise
The NHS recommends adults consume approximately 0.8g of protein per kilogram of body weight daily. During weight loss, this may increase to 1.2–1.6g/kg to protect muscle mass. Protein supplements — shakes, powders, bars — can help reach these targets conveniently, particularly if your normal diet lacks sufficient protein sources like chicken, fish, eggs, or legumes.
Check your current BMI and weight management goals using our free BMI calculator to understand where you stand, then calculate your personalised protein needs based on your weight.
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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.
Protein Supplements Alongside Weight Loss Medication
If you're exploring prescription weight loss options like GLP-1 injections (Wegovy, Mounjaro) or other weight management medication available through the NHS, adequate protein intake is critical. These medications reduce appetite significantly, which can lead to inadequate total food intake. Higher protein consumption during GLP-1 weight loss helps preserve muscle mass and ensures nutritional adequacy on smaller meal portions.
Our free GLP-1 weight loss calculator can help you understand potential weight loss at different doses — and with that projection, you'll want to ensure adequate protein intake throughout. A GP or registered dietitian can advise on personalised protein needs for your specific situation. Protein supplements make it easier to meet daily targets without excessive calorie intake.
- 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 supplements alone cause weight loss?
No. Protein supplements must be part of a calorie deficit to support weight loss. A supplement alone doesn't create the energy deficit required for fat loss. They work best combined with reduced-calorie diet choices and increased physical activity. Professional weight management support — whether lifestyle coaching or prescription medication — significantly improves outcomes.
How much protein do I need daily for weight loss?
The NHS recommends approximately 0.8g per kilogram of body weight as baseline. During weight loss, aim for 1.2–1.6g/kg to preserve muscle. Use our free weight converter to check your weight in kilograms, then multiply by 1.2–1.6 to calculate your daily target. A registered dietitian can give more personalised guidance.
Are protein supplements safe for long-term use?
Yes, for most adults. Protein supplements are safe when used as part of a balanced diet. However, those with kidney disease or certain medical conditions should seek GP advice before increasing protein intake significantly. Always choose products from reputable manufacturers with clear nutritional labelling.
Do protein supplements interfere with GLP-1 weight loss injections?
No direct interaction exists. However, GLP-1 medications (like Wegovy) significantly reduce appetite, so adequate protein intake requires intentional planning. Protein supplements can help meet daily needs on smaller meal portions. Discuss your protein strategy with your prescribing GP or a dietitian if using weight loss medication.
What's the best type of protein supplement for weight loss?
Whey, casein, and plant-based protein powders all support weight loss if they fit your calorie targets. Whey absorbs quickly; casein releases slowly. Look for options low in added sugars and with clear nutritional information. Protein shakes, bars, or powders are equally effective — choose based on convenience and personal preference. ```
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.