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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Best Protein Powder For Weight Loss — UK Options
Protein powder is a popular supplement for weight loss in the UK, but it works best alongside a calorie-controlled diet and physical activity. However, if you're struggling with weight management, prescription weight loss medication may be more effective than dietary supplements alone. The NHS and private prescribing options now offer clinically proven treatments for eligible adults. This guide explores protein powder, compares it with prescription alternatives, and explains how to find out if you qualify for weight management support in the UK.
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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 Powder vs Prescription Weight Loss Medication
Protein powder can help you feel fuller for longer, support muscle maintenance during weight loss, and provide convenient nutrition. However, protein powder alone does not address appetite hormones or metabolic factors the way prescription medications do.
UK-licensed prescription options for weight management include:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 injection that may help reduce appetite and support weight loss, with clinical trials showing average weight loss of 15–21% of body weight
- Wegovy (semaglutide) — a GLP-1 injection administered once weekly, with clinical evidence supporting average weight loss of around 15% body weight
- Saxenda (liraglutide) — a daily GLP-1 injection, another NHS-approved option
Unlike protein powder, these medications work on appetite-regulating hormones and require a clinical assessment and prescription. Try our GLP-1 weight loss calculator above to explore potential outcomes if you were eligible for prescription medication.
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 Eligibility and How to Access Weight Management Support
To access prescription weight loss medication on the NHS, you typically need 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 sleep apnoea. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may qualify at lower BMI thresholds due to higher health risks at these levels.
NHS access: Speak to your GP about referral to a specialist tier 3 weight management service. Private access: Available through licensed prescribers via online consultation without NHS referral, though costs apply. Either route requires a clinical assessment. Check your BMI using our free BMI calculator on this page to understand where you stand.
- 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.
Is protein powder effective for weight loss?
Protein powder can support weight loss when combined with a reduced-calorie diet and exercise. It helps preserve muscle, increases satiety, and provides convenient nutrition. However, it does not address hormonal appetite regulation the way GLP-1 medications do. Results vary based on overall diet and activity levels.
How does Mounjaro compare to protein powder for weight loss?
Mounjaro is a prescription injection that activates GLP-1 and GIP hormone pathways to reduce appetite and support metabolic changes. Clinical trials showed average weight loss of 15–21% of body weight when combined with diet and exercise. Protein powder supports muscle and fullness but does not have this hormonal effect.
Who can get prescription weight loss medication on the NHS?
Adults with a BMI of 30 or above, or 27 or above with weight-related health conditions, may be eligible. South Asian and other minority ethnic groups have lower eligibility thresholds. You must be referred to a specialist weight management service by your GP, and availability varies by region.
What is the difference between Mounjaro and Wegovy?
Mounjaro is a dual GIP and GLP-1 receptor agonist (up to 15 mg weekly), while Wegovy is a GLP-1 agonist only (up to 2.4 mg weekly). Both are once-weekly injections. Clinical evidence suggests Mounjaro may produce slightly higher average weight loss, but individual results vary significantly between users.
Should I use protein powder if I'm prescribed Mounjaro or Wegovy?
Yes, protein powder can complement prescription medication. It helps maintain muscle mass during weight loss and supports satiety. However, these medications may reduce appetite significantly, so you may need less protein powder than expected. Always discuss your diet with your prescriber or a dietitian.
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.