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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Best Weight Loss Diet for Polycystic Ovarian Syndrome — UK Medication Options
Polycystic ovarian syndrome (PCOS) can make weight management more challenging due to insulin resistance and hormonal factors. Alongside lifestyle changes like low glycaemic index diets and regular physical activity, prescription weight loss medication is now available through the NHS and private providers in the UK. For eligible adults with PCOS and a BMI of 30 or above (or 27+ with weight-related health conditions), GLP-1 injections like Mounjaro and Wegovy may provide additional support. This guide covers your prescription weight management options in the UK and how to explore what's available for your situation.
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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 Prescription Weight Loss Options for PCOS
Three GLP-1 receptor agonist medications are licensed in the UK for weight management and may be particularly helpful for people with PCOS, as they can improve insulin sensitivity and support appetite control:
- Mounjaro (tirzepatide) — a dual GIP/GLP-1 injection (2.5 mg to 15 mg weekly). Clinical trials showed average weight loss of 15–21% body weight at the maximum dose.
- Wegovy (semaglutide) — a GLP-1 injection (0.25 mg to 2.4 mg weekly). Average weight loss in trials was approximately 15% body weight.
- Saxenda (liraglutide) — a GLP-1 injection taken daily (0.6 mg to 3 mg). Slightly lower average weight loss (approximately 5–9%) but established safety profile.
All three are prescription-only and require a clinical assessment. Individual results vary significantly. These work alongside — not instead of — dietary changes and increased physical activity for best results.
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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
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NHS Eligibility and How to Access Treatment
To access prescription weight loss medication through the NHS, you'll typically need referral to a specialist tier 3 weight management service from your GP. Eligibility generally requires a BMI of 30 or above, or 27–29.9 with a weight-related condition (PCOS qualifies). NHS availability varies significantly by region and waiting lists can be lengthy.
Alternatively, prescription weight loss medication is available through private online prescribing services following an online clinical assessment. This offers faster access without an NHS referral, though you'll pay privately (typically £129–£320+ per month depending on dose). Start by speaking with your GP about your weight management goals — they can discuss both NHS and private options, and assess whether prescription medication is appropriate for your individual circumstances.
- 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.
Does GLP-1 medication work specifically for PCOS weight loss?
GLP-1 medications are not specifically approved for PCOS, but they may help people with PCOS lose weight through reduced appetite and improved insulin sensitivity. Since PCOS often involves insulin resistance, the metabolic effects of GLP-1 drugs may be particularly beneficial. However, results vary individually, and medication works best alongside diet, exercise, and PCOS-specific management (such as anti-androgen medication if prescribed). Speak with your GP or specialist about whether GLP-1 is right for your PCOS management.
What's the best diet for PCOS weight loss?
Evidence suggests a low glycaemic index (GI) diet is beneficial for PCOS, as it helps manage blood sugar and insulin levels. Focus on whole grains, lean protein, non-starchy vegetables, and healthy fats; limit refined carbohydrates and sugary foods. A moderate calorie deficit (around 500 kcal/day) typically supports 0.5–1 kg per week weight loss. Mediterranean and DASH diets also have strong evidence. Your GP or a dietitian can provide personalised guidance.
Can I get weight loss injections on the NHS for PCOS?
Yes, if you meet eligibility criteria (BMI ≥30, or 27–29.9 with comorbidities such as PCOS-related health issues). You'll need a GP referral to your local specialist weight management service, where a team will assess whether prescription medication is appropriate. NHS availability and waiting times vary by region. Your GP can tell you what's available locally and help with the referral process.
How much weight can I lose with GLP-1 medication?
Clinical trials show average weight loss of 5–21% of body weight depending on the medication and dose. However, individual results vary considerably — some people lose more, some less. Weight loss depends on factors including your starting weight, adherence to treatment, diet, exercise, and individual metabolism. Your GP or prescriber can discuss realistic expectations for your situation.
Are weight loss injections safe for people with PCOS?
GLP-1 medications are generally well-tolerated, with nausea and digestive changes being common side effects (especially initially). People with PCOS don't have higher risk of side effects. However, individual safety and suitability must be assessed by a prescriber before starting treatment. Tell your prescriber about all your health conditions and medications so they can ensure the medication is safe and appropriate for you.
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.