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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Female Weight Loss Before and After: UK Prescription Options
Weight loss journeys look different for every woman, and for some, prescription medication may be part of a sustainable approach alongside diet and exercise. If you're exploring weight management options in the UK, it's helpful to understand what prescription treatments are available, how they work, and whether you might be eligible through the NHS or private prescribing. This guide covers the science, eligibility, and practical steps to discuss weight loss medication with your GP.
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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 Weight Loss Medications for Women
Three prescription-only medications are currently licensed in the UK for weight management in women: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Mounjaro and Wegovy are once-weekly injections, while Saxenda is a daily injection.
Clinical evidence shows that women taking these GLP-1 or GIP/GLP-1 medications alongside a reduced-calorie diet and increased physical activity have experienced average weight loss of 14–21% of their body weight in clinical trials — though individual results vary significantly. These medications work by activating natural hunger-control hormones, helping reduce appetite and cravings.
Eligibility: You may be eligible if your BMI is 30 or above, or 27 or above with a weight-related health condition such as type 2 diabetes, high blood pressure, or cardiovascular disease. Women of South Asian, Chinese, Black African, or Black Caribbean heritage may have slightly lower BMI eligibility thresholds due to increased health risk at lower weights.
Use our free GLP-1 weight loss calculator to explore projected outcomes at different doses, and our BMI calculator to check your starting point.
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 Access vs Private Prescribing in the UK
NHS access: Weight loss medication is available through specialist tier 3 and tier 4 weight management services, typically accessed via GP referral. NICE has approved tirzepatide (Mounjaro) for use within NHS specialist services. However, access varies significantly by region, and waiting lists can be lengthy in many areas — sometimes months to over a year depending on your local integrated care board.
Private access: You can obtain a prescription without NHS referral through a UK-licensed prescriber via a private online consultation. This typically involves a health questionnaire and assessment, and prescriptions are dispensed by GPhC-registered pharmacies. Costs range from approximately £129–£320 per month depending on dose and provider.
The first step in either route is a conversation with your GP about your weight management goals and whether prescription treatment might be appropriate for you.
- 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.
How much weight do women typically lose with prescription weight loss medication?
Clinical trials show average weight loss of 14–21% of body weight over 68 weeks, alongside diet and exercise. For example, a woman weighing 90kg might lose 13–19kg on average. However, individual results vary significantly — some women lose more, some less. Your progress tracker can help you monitor your personal journey.
Can I access weight loss injections through the NHS if I'm a woman?
Yes, if you meet eligibility criteria (BMI 30+, or 27+ with weight-related health conditions) and are referred to a specialist weight management service. However, availability varies by region and waiting times can be long. Your GP can advise whether you're eligible and what local services are available.
What's the difference between Mounjaro and Wegovy for women?
Mounjaro (tirzepatide) is a dual GIP/GLP-1 agonist with doses up to 15mg weekly. Wegovy (semaglutide) is a GLP-1 agonist with doses up to 2.4mg weekly. Both are once-weekly injections. Mounjaro showed slightly higher average weight loss in trials (20.9% vs 14.9%), but both are effective. Your prescriber will recommend the most suitable option.
Are there side effects women should know about with these medications?
Common side effects include nausea, diarrhoea, constipation, and stomach discomfort — usually mild and temporary. These tend to improve as your body adjusts. Serious side effects are rare but can include pancreatitis and gallbladder problems. Your prescriber will discuss all risks and benefits before you start treatment.
How do I find out if I'm eligible for weight loss medication?
Start by speaking with your GP about your weight management goals. They can assess your BMI, health conditions, and whether prescription treatment might be suitable. You can also use our free BMI calculator to check your current BMI against NHS eligibility thresholds, then take that information to your GP appointment.
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.