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
Type 2 Weight Loss: What You Need to Know
If you have type 2 diabetes or prediabetes, weight loss can significantly improve your blood sugar control and overall health. Type 2 weight loss refers to managing weight when you have type 2 diabetes—a condition where your body struggles to regulate blood sugar effectively. Even a 5–10% reduction in body weight can improve insulin sensitivity, reduce medication needs, and lower your risk of serious complications. The NHS recommends a sustainable approach combining dietary changes, increased physical activity, and—where appropriate—prescription weight loss medication. Our free BMI calculator can help you understand your current weight range and set realistic targets.
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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.
GLP-1 Medications and Type 2 Weight Management
GLP-1 receptor agonist medications like Wegovy (semaglutide) and Mounjaro (tirzepatide) are now licensed in the UK for weight management in adults with type 2 diabetes or prediabetes. These prescription-only injections may help regulate appetite, reduce food cravings, and improve blood sugar control simultaneously.
In the STEP-1 clinical trial, Wegovy helped participants lose an average of approximately 15% of their body weight over 68 weeks—though individual results vary significantly. Mounjaro, using a dual GIP and GLP-1 mechanism, showed slightly higher average weight loss of around 20.9% at the maximum dose in clinical trials. Both medications work alongside a reduced-calorie diet and increased physical activity.
Important: These are prescription-only medicines. Access through the NHS involves referral to a specialist tier 3 weight management service, though waiting lists vary by region. Private prescribing is also available following an online clinical assessment.
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 Weight Loss Support and Eligibility
The NHS offers structured weight management support through its tiered pathway. If you have type 2 diabetes or prediabetes with a BMI of 27 or above (or 30+ without comorbidities), you may be eligible for specialist support and prescription weight loss treatment.
Your GP can refer you to tier 3 services, which may include behaviour change programmes, dietary support, and consideration for medication. The NHS Weight Loss Plan is free and available online. Using our free weight loss calculator can help you project potential outcomes with GLP-1 medication and understand realistic timescales. Remember that sustainable weight loss of 0.5–1 kg per week is safest and most likely to be maintained long-term.
- 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 I lose weight if I have type 2 diabetes?
Yes. Weight loss is highly effective for type 2 diabetes management. Even 5–10% body weight reduction improves blood sugar control, reduces insulin resistance, and may lower medication needs. Always work with your GP to adjust any diabetes medications safely as you lose weight.
What is the difference between Wegovy and Mounjaro for type 2 weight loss?
Both are prescription GLP-1/GIP medications licensed for weight management in the UK. Wegovy (semaglutide) is a GLP-1 agonist; Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist. Clinical trials showed Mounjaro produced slightly higher average weight loss, but individual results vary. Your prescriber will assess which is more suitable for you.
How do I access GLP-1 weight loss medication on the NHS for type 2 diabetes?
Ask your GP for a referral to your local tier 3 specialist weight management service. They will assess your eligibility based on BMI, health conditions, and previous weight management attempts. NHS access varies by region and may involve waiting lists. Private prescribing offers faster access following an online clinical assessment.
Is weight loss assured with type 2 diabetes medication?
No. While clinical trials show GLP-1 medications help most people lose weight, individual results vary significantly. Success depends on medication response, adherence to a reduced-calorie diet, physical activity, and personal factors. Your GP or prescriber can discuss realistic expectations for your situation.
What's a healthy weight loss rate if I have type 2 diabetes?
The NHS recommends losing 0.5–1 kg (1–2 lbs) per week for sustainable, safe weight loss. Faster loss risks muscle loss and is harder to maintain. Use our BMI calculator to identify your healthy weight range, then work with your GP or dietitian on a realistic timeline for reaching it.
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.