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 Diets For Women: UK Prescription Options
Weight loss diets work best when combined with professional support — and for many UK women, prescription weight loss medication can be part of that approach. If you're considering options beyond diet and exercise alone, this guide explains the prescription medications available through the NHS and privately, how to check your eligibility, and what to expect. Calculate your BMI using our free tool above to understand your starting point, and explore whether prescription weight management might be suitable for you.
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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 Medications for Women
Three prescription medications are currently licensed in the UK specifically for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All are GLP-1 receptor agonists (or dual GIP/GLP-1 in Mounjaro's case) — medications that work by helping regulate appetite and blood sugar control. Clinical trials have shown that these medications, when combined with diet and lifestyle changes, support weight loss for eligible women.
- Mounjaro: Once-weekly injection, doses 2.5–15 mg. Clinical trial average: ~15–clinically studied weight loss over 72 weeks.
- Wegovy: Once-weekly injection, doses 0.25–2.4 mg. Clinical trial average: ~clinically studied weight loss over 68 weeks.
- Saxenda: Once-daily injection, doses 0.6–3 mg. Available for several years; evidence supports modest weight loss alongside lifestyle changes.
Individual results vary significantly. Your GP or prescriber will assess which option, if any, suits your personal health profile.
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 and Private Options for UK Women
In the UK, access to prescription weight loss medication through the NHS is managed by specialist weight management services (tier 3 and tier 4 care). Your GP can refer you, but availability varies significantly by region — waiting lists can be lengthy in many areas. Alternatively, prescription weight loss medication is available privately through UK-licensed online prescribers, who conduct a clinical assessment and issue a prescription if appropriate.
- Ask your GP about local NHS weight management services and referral eligibility
- Check your BMI and weight-related health conditions to understand potential eligibility
- Private prescribing is available without an NHS referral, though costs typically range £129–£320 per month depending on medication and dose
- Use our free GLP-1 weight loss calculator to explore projected outcomes at different doses
- 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.
Am I eligible for prescription weight loss medication?
You may be eligible if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). A GP or licensed prescriber will assess your individual circumstances. Use the BMI calculator on this page to check your BMI as a first step.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are prescription-only injections given once weekly. Mounjaro (tirzepatide) activates two hormone pathways (GIP and GLP-1), while Wegovy (semaglutide) activates one (GLP-1 only). Clinical trials showed slightly higher average weight loss with Mounjaro, but individual results vary. Your prescriber will recommend the most suitable option for you.
Can I access weight loss medication through the NHS?
Yes, if referred to an NHS specialist weight management service. However, NHS availability is limited and varies by region — you may face a waiting list. Private prescribing through a UK-licensed provider is an alternative that doesn't require an NHS referral, though there is a cost involved.
Do prescription weight loss medications work without diet changes?
No. Medications like Mounjaro and Wegovy are designed to support weight loss alongside a reduced-calorie diet and increased physical activity, not replace them. The combination of medication plus lifestyle change is what produces results. Track your progress with our free progress tracker.
What should I discuss with my GP about weight loss medication?
Ask about NHS specialist weight management services in your area, eligibility criteria, and whether prescription medication might be appropriate for you. Bring your weight, height, and any relevant health conditions (diabetes, blood pressure, sleep issues). Your GP can then refer you to specialist services or discuss private 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.