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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Weight Loss Options for Women in the UK
While dietary supplements are widely available, prescription weight management options are often more effective for women seeking significant weight loss in the UK. If you're looking for evidence-based support, the NHS and private prescribers offer licensed medications alongside lifestyle changes. This guide covers what's available, who's eligible, and how to access weight loss treatment through NHS weight management services or private prescribing 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.
UK-Licensed Prescription Weight Loss Options for Women
Three prescription medications are licensed in the UK specifically for weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist given once weekly. Clinical trials showed women lost an average of 15–21% of their body weight alongside reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a GLP-1 receptor agonist given once weekly. Evidence suggests an average weight loss of around 15% body weight in clinical trials.
- Saxenda (liraglutide) — a GLP-1 receptor agonist given daily by injection. Smaller needle than the weekly options but requires daily administration.
All three are prescription-only medicines available in the UK through NHS specialist weight management services or private online prescribing following clinical assessment. Individual results vary significantly, and medication works best when combined with dietary changes and increased physical activity.
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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.
NHS vs. Private Access: How to Get Started
On the NHS, women can access prescription weight loss medication through tier 3 specialist weight management services, typically after referral from their GP. Eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or high blood pressure. However, NHS waiting lists vary significantly by region, and availability is not universal.
Privately, GPhC-registered online prescribers can assess eligibility and issue prescriptions without NHS referral. The first step is always a conversation with your GP about whether prescription weight loss treatment might be appropriate for you. Use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator can help you understand potential outcomes at different doses.
Check your personal BMI with our free BMI calculator on this page to see where you fall on NHS guidance. If you're interested in understanding projected weight loss, try our GLP-1 weight loss calculator for an estimate of potential outcomes. Your GP can discuss which NHS tier 3 services are available in your area or refer you for assessment.
- 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 difference between supplements and prescription weight loss medication?
Over-the-counter supplements have limited evidence for weight loss. Prescription medications like Mounjaro and Wegovy have undergone rigorous clinical trials in the UK and are licensed by the MHRA. They work through specific hormone mechanisms (GLP-1 and GIP pathways) that affect appetite, fullness, and food cravings. Prescription options typically produce greater weight loss than supplements when combined with lifestyle changes.
Am I eligible for NHS weight loss medication?
Generally, yes, if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. Eligibility varies by region. Speak to your GP about referral to your local tier 3 weight management service. For South Asian, Chinese, Black African, or Black Caribbean women, lower BMI thresholds may apply.
How much weight can I expect to lose?
Clinical trials show average losses of 15–21% body weight with Mounjaro and around 15% with Wegovy over 12–18 months, alongside diet and exercise. However, individual results vary significantly — some people lose more, some less. Your prescriber will discuss realistic expectations based on your situation. Weight loss is gradual and typically continues as you move to higher doses.
Can I get prescription weight loss medication on the NHS?
Yes, if you're eligible and referred to a specialist tier 3 weight management service by your GP. NHS services are free, but availability and waiting times vary by region. Private online prescribers also offer these medications following an online clinical assessment, though this involves a fee. Check what's available locally first by asking your GP.
How do I know if prescription weight loss is right for me?
Your GP or a prescriber will assess your medical history, current medications, and weight-related health conditions. Not everyone is suitable — for example, pregnancy, certain medical conditions, or specific medications may make it unsuitable. A clinical assessment is always required before prescription. Your GP is the best starting point to discuss your options.
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.