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
Free tracker included with every download this week
Can You Take Mounjaro If You Have PCOS?
Yes, you can take Mounjaro if you have PCOS (polycystic ovary syndrome), and it may be a suitable option for weight management in this context. PCOS often makes weight loss more difficult due to insulin resistance and hormonal imbalances, which means weight management support is particularly valuable. However, whether Mounjaro is right for you depends on your individual health profile, other medications, and an assessment by your GP or a qualified prescriber following a proper clinical evaluation.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
PCOS, Weight, and Mounjaro Eligibility in the UK
PCOS (polycystic ovary syndrome) is a hormonal condition affecting many UK women of reproductive age. It commonly leads to insulin resistance, making weight loss significantly harder than in people without PCOS. This is why PCOS is recognised as a weight-related health condition that may qualify you for prescription weight loss support under NHS guidelines.
If you have PCOS and a BMI of 27–29.9 kg/m², you may be eligible for Mounjaro through NHS specialist tier 3 weight management services, as PCOS counts as a qualifying comorbidity. If your BMI is 30 or above, you are also eligible. However, tirzepatide (the active ingredient in Mounjaro) has not been specifically studied in large trials for PCOS, so your prescriber will assess your individual suitability during the clinical assessment.
- Your GP can refer you to tier 3 specialist services for assessment
- Private prescription is also available if you meet eligibility criteria
- A prescriber must confirm PCOS does not contraindicate Mounjaro for you
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 vs Private Routes and PCOS Considerations
Through the NHS, access to Mounjaro is via tier 3 specialist weight management services — your GP refers you, though waiting lists vary significantly by region. Private prescribing through a GPhC-registered online pharmacy is faster, requiring an online clinical assessment where you disclose your PCOS diagnosis. Both routes require a prescriber to review your PCOS management plan and any medications you are taking (such as metformin), as Mounjaro may affect oral medication absorption.
Track your weight loss progress throughout your Mounjaro journey using our free progress tracker, and use our GLP-1 weight loss calculator to see projected outcomes at different doses. Your GP or prescriber will monitor you regularly during 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.
Does Mounjaro interact with PCOS medications like metformin?
Mounjaro may reduce the absorption of oral medications, including metformin. Your prescriber needs to know about all medications you're taking. You may need dose adjustments or timing changes — this will be discussed during your clinical assessment and monitored regularly by your healthcare provider.
Is Mounjaro safe for women with PCOS who want to conceive?
Mounjaro is not recommended during pregnancy. If you're planning to become pregnant, inform your prescriber — they may suggest stopping Mounjaro in advance. PCOS and fertility are complex; discuss family planning with your GP alongside any weight management plan.
Will Mounjaro help with PCOS symptoms like irregular periods?
Mounjaro is approved for weight management, not for treating PCOS itself. However, weight loss can help regulate hormones and improve menstrual regularity in PCOS. Any improvement in PCOS symptoms would be a secondary benefit of weight loss, not a direct effect of the medication.
Can I get Mounjaro on the NHS if I have PCOS?
Yes, PCOS qualifies as a weight-related health condition for NHS eligibility. If your BMI is 27–29.9 with PCOS, or 30+, you may be eligible for NHS tier 3 specialist services. However, availability and waiting times vary by region and local ICB (integrated care board) decisions.
What should I tell my prescriber about my PCOS before starting Mounjaro?
Disclose your PCOS diagnosis, all current medications (especially metformin and hormonal contraceptives), any fertility plans, any history of gallbladder or pancreas problems, and whether you've had gestational diabetes. This information helps your prescriber assess whether Mounjaro 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.