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 Supplements in the UK
If you're looking for weight loss supplements for women in the UK, prescription weight management medications offer evidence-based options beyond over-the-counter products. The NHS and private prescribers can provide access to licensed weight loss injections like Mounjaro and Wegovy for eligible women. This guide explains how these prescription medications work, who qualifies, and how to access them through both NHS weight loss services and private prescribing. Understanding your options helps you make an informed decision with your GP or healthcare provider.
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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 weight loss medications are currently licensed in the UK and available to eligible women. These are not supplements but prescription-only medicines that work through hormone pathways naturally present in the body.
- Mounjaro (tirzepatide) — a once-weekly injection that activates both GIP and GLP-1 hormone pathways. Clinical trials showed women lost an average of 15–21% of body weight over 72 weeks, though individual results vary significantly.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical evidence demonstrated average weight loss of approximately 15% body weight alongside dietary changes and increased physical activity.
- Saxenda (liraglutide) — a daily GLP-1 injection, less commonly prescribed than weekly options but also available.
All require a prescription following a clinical assessment by your GP or a licensed prescriber. Eligibility depends on BMI and health factors. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and check your BMI using our calculator to understand where you sit on the NHS weight categories for women.
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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 Access vs Private Options for Women
Access to weight loss medication in the UK follows two main routes. NHS access is through specialist tier 3 weight management services — your GP can refer you if you meet eligibility criteria (typically BMI ≥30, or BMI 27–29.9 with weight-related health conditions). NHS waiting lists vary significantly by region, and some areas have limited capacity.
Private prescribing offers faster access through GPhC-registered online consultants who assess suitability and issue prescriptions if appropriate. Costs typically range from £129–£320 per month depending on medication and dose.
Speak with your GP about weight loss medication options and whether you meet NHS eligibility criteria. They can discuss the medication landscape and your personalised health situation. Track your progress with our free progress tracker once you start any weight loss plan.
- 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 weight loss supplements and prescription medications?
Over-the-counter supplements have limited clinical evidence. Prescription weight loss medications like Mounjaro and Wegovy are licensed by the MHRA and shown in clinical trials to support weight management. They require a prescription and clinical assessment because they affect hormone pathways and may have side effects requiring monitoring. Prescription options offer stronger evidence-based support for eligible women.
Who is eligible for prescription weight loss medication in the UK?
Generally, women with a BMI of 30 or above, or BMI 27–29.9 with weight-related health conditions (like diabetes, high blood pressure, or sleep apnoea) may be eligible. For women of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply. Your GP or prescriber assesses individual eligibility based on your health profile.
How quickly do prescription weight loss medications work for women?
Weight loss is gradual and individual. Clinical trials show results emerge over weeks and months, not days. Most people see measurable change after 4–8 weeks, with continued loss over 12–20 weeks. Results depend on dose, adherence, diet, and physical activity. Individual outcomes vary — some women experience faster loss than others at the same dose.
Can I use weight loss medication alongside diet and exercise?
Yes — this is the recommended approach. Prescription weight loss medications work best alongside a reduced-calorie diet and increased physical activity. They're not a replacement for lifestyle changes; they support and enhance those efforts. Your prescriber and GP will discuss a holistic plan tailored to your health.
Are there side effects women should know about?
Common side effects include nausea, diarrhoea, constipation, and reduced appetite — these often improve over time as your body adjusts. Serious side effects are rare but can include pancreatitis or gallbladder issues. Always report any persistent symptoms to your prescriber. The benefits and risks are discussed during your clinical assessment.
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.