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
Weights or Cardio for Weight Loss — Which Is Better?
Both weights and cardio play important roles in weight loss, but they work differently. Cardio burns calories quickly during exercise, whilst resistance training builds muscle that increases your resting metabolic rate. For sustainable weight management in the UK, most evidence supports combining both approaches alongside a reduced-calorie diet. If you're struggling with weight loss despite lifestyle changes, prescription weight loss medication is now available for eligible adults through the NHS or private prescribing. Use our free BMI calculator to check your personal starting point and our GLP-1 weight loss calculator to explore options if you qualify.
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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.
Weights vs Cardio: How They Support Weight Loss
Cardio exercise (running, cycling, swimming) burns calories during and shortly after activity, making it effective for creating a calorie deficit. The NHS recommends at least 150 minutes of moderate-intensity aerobic activity weekly for adults.
Resistance training (weights, bodyweight exercises) burns fewer calories during the session but builds lean muscle mass, which increases your metabolic rate at rest. This means you burn more calories throughout the day, even when inactive.
For optimal weight loss results, combine both: cardio for immediate calorie burn, and weights for long-term metabolic benefits. A balanced approach of 150 minutes cardio plus 2 days resistance training weekly, alongside a reduced-calorie diet, supports sustainable weight management. Individual results vary based on consistency, diet quality, and genetics. For adults with a BMI of 30 or above, or 27+ with weight-related health conditions, prescription weight loss medication may provide additional support alongside exercise and dietary changes.
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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.
Prescription Weight Loss Medication — UK Options
For adults in the UK struggling to lose weight despite exercise and diet, three prescription medications are licensed for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These work by reducing appetite and supporting feeling fuller on smaller portions, complementing your cardio and weight training efforts.
NHS access: Referral to specialist tier 3 weight management services, typically requiring a BMI of 30+ or 27+ with weight-related conditions. Availability varies by region and waiting lists can be lengthy.
Private access: Through online prescribers following a clinical assessment, available without NHS referral. Costs range approximately £129–£320 monthly depending on medication and dose.
Talk to your GP about whether prescription support is appropriate for you. Try our free GLP-1 weight loss calculator to estimate potential outcomes if you're eligible for medication-assisted weight management.
- 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 cardio better than weights for weight loss?
Neither is inherently "better"—both support weight loss through different mechanisms. Cardio creates an immediate calorie deficit, whilst weights build muscle that increases resting metabolism. The NHS recommends combining both alongside a reduced-calorie diet for optimal, sustainable results. Individual effectiveness depends on consistency and personal preference.
How much cardio do I need to lose weight?
The NHS recommends 150 minutes of moderate-intensity cardio weekly as a baseline for health. For weight loss, creating a calorie deficit matters most—cardio helps achieve this, but diet is equally important. A 500 kcal daily deficit typically results in approximately 0.5 kg weight loss per week.
Can you lose weight with weights alone?
Weights alone can support weight loss by building muscle and increasing metabolic rate, but cardio burns calories more quickly during exercise. Most evidence supports combining both for faster, more sustainable results. Diet remains the foundation—exercise amplifies calorie deficit but cannot override a surplus diet.
What prescription weight loss options are available on the NHS in the UK?
Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide) are licensed for NHS prescription through specialist tier 3 weight management services. Eligibility typically requires a BMI of 30+ or 27+ with weight-related health conditions. Regional availability and waiting lists vary significantly.
How can I find out if I'm eligible for prescription weight loss medication?
Speak with your GP about referral to specialist weight management services. You can also check your BMI using our free BMI calculator on this page. Private prescribers offer online assessments if you prefer not to use NHS services. Eligibility requires a BMI of 30+ or 27+ with existing health conditions like hypertension or type 2 diabetes.
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.