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 Transformation for Women in the UK
Weight loss transformation is a personal health journey, and women have several evidence-based prescription options available in the UK. If you're considering medication-supported weight management, understanding what's available through the NHS and privately can help you make an informed decision. This guide covers prescription weight loss medications licensed for women in the UK, eligibility criteria, and how to start a conversation with your GP about whether medication might support your weight loss goals alongside healthy eating and physical activity.
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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 currently licensed in the UK for weight management in women:
- Mounjaro (tirzepatide) — a once-weekly injection that activates two natural hormone pathways (GIP and GLP-1), helping regulate appetite and reduce cravings. Clinical trials showed women lost an average of 15–21% of their body weight over 72 weeks, though individual results vary significantly.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection that slows stomach emptying and supports feeling fuller after smaller meals. Women in clinical trials lost approximately 15% of body weight on average at the maximum dose.
- Saxenda (liraglutide) — a daily GLP-1 injection, typically used when once-weekly options are not suitable. All three medications are prescription-only and require a clinical assessment before being prescribed. They work most effectively when combined with reduced-calorie eating and increased physical activity, not as a standalone solution.
Your prescriber will assess which option, if any, is appropriate for your individual health, medical history, and weight loss goals. Use our free GLP-1 weight loss calculator to explore projected weight loss at different doses.
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 Routes for Women
In the UK, women can access prescription weight loss medication through two pathways. NHS access is available through specialist tier 3 weight management services — typically by GP referral — though waiting lists and availability vary significantly by region. Private access is available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber, without requiring an NHS referral.
Eligibility generally requires a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with at least one weight-related health condition (such as type 2 diabetes, hypertension, or sleep apnoea). For women of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply due to higher health risks at lower weights. Use our BMI calculator to check your personal BMI, then discuss your options with your GP or a licensed prescriber.
- 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 women take Mounjaro and Wegovy if they want to become pregnant?
No. Both Mounjaro and Wegovy should not be used during pregnancy or while planning pregnancy. Women should use a reliable contraceptive method and inform their prescriber of any pregnancy plans. It's essential to discuss contraception and family planning with your GP or prescriber before starting these medications.
What's the difference between Mounjaro and Wegovy for women's weight loss?
Mounjaro uses dual GIP and GLP-1 activation, while Wegovy is GLP-1 only. Clinical evidence suggests Mounjaro may produce slightly higher average weight loss (15–21% vs approximately 15%), but individual results vary. Your prescriber will recommend the option most suitable for your health profile and circumstances.
How quickly do women typically see weight loss results with these medications?
Weight loss usually becomes noticeable after 4–8 weeks, with more significant changes by 12–16 weeks. However, individual timelines vary based on dose, adherence, diet, and activity level. Using a progress tracker can help you monitor changes beyond just the scales.
Are there common side effects women should expect?
The most common side effects include nausea, constipation, diarrhoea, and stomach discomfort — particularly in the first few weeks. These often improve as your body adjusts. Serious side effects are rare but include severe stomach pain (possible pancreatitis) or gallbladder issues. Always report concerns to your prescriber immediately.
How do I start the conversation with my GP about weight loss medication?
Book an appointment and discuss your weight management goals, medical history, and any weight-related health conditions. Your GP can assess your BMI, explain NHS options, provide a specialist referral if eligible, or discuss private routes. Being honest about your health priorities helps your GP give personalised advice.
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.