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
How to Boost Weight Loss — What Works in the UK
Boosting weight loss requires a combination of proven strategies tailored to your individual circumstances. Whether through dietary changes, increased physical activity, lifestyle modifications, or prescription weight management options, there are multiple evidence-based approaches available to UK adults. The NHS recommends a sustainable approach alongside professional support when needed. Our free BMI calculator and weight management tools can help you track progress and understand your current health status as you work towards your goals.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Effective Strategies to Boost Weight Loss
The most effective approach to boost weight loss combines several evidence-based methods:
- Create a calorie deficit: A deficit of approximately 500 kcal per day typically results in losing around 0.5 kg per week — the NHS-recommended sustainable rate. Our free weight converter can help you track progress in kg, stone, or lbs.
- Dietary changes: Focus on whole foods, increase protein intake to support muscle retention, reduce processed foods, and consider structured approaches like the Mediterranean diet which has strong evidence for both weight loss and cardiovascular health.
- Regular physical activity: Combine cardio with resistance training to preserve muscle mass during weight loss. Even moderate activity (150 minutes weekly) significantly improves outcomes.
- Prescription weight management medication: For eligible UK adults, GLP-1 weight loss injections like Wegovy (semaglutide) or Mounjaro (tirzepatide) may support weight management alongside lifestyle changes. Clinical trials showed average weight loss of 15–21% body weight, though individual results vary significantly.
Use our GLP-1 weight loss calculator to estimate potential results if prescription medication is suitable for you.
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.
Prescription Weight Loss Options in the UK
GLP-1 medications can help boost weight loss by reducing appetite and supporting feelings of fullness. Wegovy (semaglutide 2.4 mg) and Mounjaro (tirzepatide up to 15 mg) are prescription-only weight management injections available in the UK. Both require clinical assessment to confirm eligibility — typically a BMI of 30 or above, or 27+ with weight-related health conditions like type 2 diabetes or high blood pressure.
Access is available through NHS specialist weight management services (with potential waiting lists) or private online prescribing following assessment by a UK-licensed prescriber. Weight loss medication works best when combined with reduced-calorie diet and increased physical activity. Individual results vary — some people lose more weight than others on the same medication.
- 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.
What's the fastest safe way to boost weight loss?
The NHS recommends losing 0.5–1 kg per week for sustainable results. This typically requires a 500–1000 kcal daily deficit through diet and exercise combined. Faster loss risks muscle loss and nutrient deficiency. Prescription weight loss medication may accelerate results when combined with lifestyle changes, but always requires professional assessment.
Can prescription weight loss injections boost my weight loss results?
Yes, GLP-1 medications like Wegovy and Mounjaro may help boost weight loss. Clinical trials showed average losses of 15–21% body weight over 68 weeks when combined with diet and exercise. However, individual results vary significantly, and prescription is only available following clinical assessment by a GP or licensed prescriber.
How does the NHS help boost weight loss?
The NHS offers a tiered approach: tier 1 includes digital tools and community programmes, tier 2 provides primary care support, and tier 3 specialist services can prescribe weight loss medication for eligible adults. Your GP can refer you to appropriate support based on your BMI and health needs.
Will weight loss medication boost results without diet changes?
No. Prescription weight loss medications like Wegovy and Mounjaro work best alongside a reduced-calorie diet and increased physical activity. These medications support appetite control, but sustainable weight loss requires lifestyle changes. They're a tool to support your efforts, not a replacement for them.
What's the best way to track if I'm boosting weight loss?
Use our free progress tracker to log weekly weigh-ins and monitor trends over time. Calculate your BMI regularly with our free BMI calculator to understand your health status. Weight fluctuates daily, so track weekly averages rather than daily changes. Take measurements and photos for progress you might not see on the scales.
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.