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 Plan: Prescription Medication Options in the UK
A female weight loss plan in the UK can include prescription medication as part of a comprehensive approach to weight management. If you have a BMI of 30 or above, or 27 or above with weight-related health conditions like type 2 diabetes or high blood pressure, you may be eligible for prescription weight loss treatment. The NHS and private prescribers offer several licensed options. This guide explains what's available, who qualifies, and how to get started with your GP or a licensed healthcare professional.
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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 Prescription Weight Loss Options for Women
Three prescription medications are licensed in the UK specifically for weight management and may be recommended as part of a female weight loss plan:
- Mounjaro (tirzepatide) — A dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed an average weight loss of 15–21% body weight at the highest dose, alongside a reduced-calorie diet and increased physical activity. Individual results vary significantly.
- Wegovy (semaglutide) — A GLP-1 receptor agonist, once-weekly injection. Evidence from clinical trials demonstrated an average weight loss of approximately 15% body weight. Results depend on adherence and lifestyle changes.
- Saxenda (liraglutide) — A daily GLP-1 injection. A third option, though less commonly prescribed than Mounjaro or Wegovy. Average weight loss is approximately 5–10% body weight.
All three are prescription-only and require a clinical assessment before being prescribed. You can use our free GLP-1 weight loss calculator to explore potential outcomes at different doses and understand how these medications may support your weight management journey.
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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 and How to Get Started
In the UK, you can access prescription weight loss medication through two routes. NHS access is through specialist tier 3 weight management services; your GP can refer you, though waiting lists vary significantly by region and can be lengthy. Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber — this is often faster but involves private cost.
To find out if you're eligible, check your BMI using our free BMI calculator on this page, then speak to your GP about your weight management goals. Your GP can assess whether prescription medication is appropriate and discuss whether NHS referral or private options suit your needs. They can also ensure any medication complements your overall health plan.
A successful female weight loss plan combines medication with sustainable lifestyle changes. Weight loss injections work best alongside a reduced-calorie diet, increased physical activity, and behaviour change support. The NHS recommends losing weight at a rate of 0.5–1 kg per week for sustainable results. You can track your progress using our free progress tracker to monitor weight loss and stay motivated. Remember, individual results vary — what works for one person may be different for another, and a prescriber will assess your individual circumstances before recommending treatment.
- 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 BMI do I need to be eligible for prescription weight loss medication in the UK?
Women with a BMI of 30 or above are generally eligible. Those with a BMI of 27–29.9 may also be eligible if they have weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or cardiovascular disease. If you're of South Asian, Black African, Black Caribbean, or Chinese heritage, lower thresholds may apply due to higher health risks at the same BMI.
Can I get weight loss injections on the NHS?
Yes, weight loss medications are available through NHS specialist weight management services (tier 3). Your GP can refer you, but availability and waiting times vary significantly by region. Some areas have limited capacity. Private access through licensed online prescribers is also available and often faster, though this involves private cost.
How long does it take to see weight loss results with prescription medication?
Results typically begin within the first few weeks, though individual timelines vary. Clinical trials showed meaningful weight loss over 12–20 weeks as doses are gradually increased. Most people reach their dose by around week 20. Continued weight loss depends on adherence to the medication, diet, and physical activity. Your prescriber can advise on realistic timelines for your circumstances.
Are weight loss injections safe for women?
Prescription weight loss medications are licensed by the MHRA and deemed safe when prescribed appropriately following clinical assessment. However, they are not suitable for everyone — for example, they're not recommended during pregnancy or if you're planning to become pregnant. Side effects are possible and vary by individual. Your GP or prescriber will assess whether the medication is suitable for you.
What's the difference between Mounjaro and Wegovy for women?
Both are once-weekly injections, but Mounjaro is a dual GIP/GLP-1 agonist while Wegovy is a GLP-1 agonist only. Clinical trials suggest Mounjaro may result in slightly higher average weight loss (15–21% vs ~15%), though individual results vary. Maximum doses also differ (15 mg for Mounjaro, 2.4 mg for Wegovy). Your prescriber will recommend based on your health profile and suitability.
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.