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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HRT and Weight Loss — What You Need to Know
Hormone replacement therapy (HRT) can affect how your body manages weight, and many people wonder whether weight loss is possible during treatment. The relationship between HRT and weight management is complex — some people gain weight, others maintain their weight, and some find weight loss more challenging. This guide explains how HRT influences your metabolism, what the NHS recommends, and what weight management options are available to you in the UK.
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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.
How HRT Affects Weight and Metabolism
HRT replaces oestrogen and progesterone (or oestrogen alone) to manage menopausal symptoms. These hormones influence how your body stores fat, uses energy, and controls appetite. During menopause without HRT, many people experience an increase in body fat, particularly around the abdomen, because oestrogen helps regulate metabolism and fat distribution. HRT can help restore some metabolic stability, but individual responses vary significantly.
- Metabolic slowdown: Oestrogen decline naturally reduces resting metabolic rate by up to 2–8% — HRT may partially offset this
- Fat distribution: Lower oestrogen favours abdominal fat storage; HRT can help shift this pattern
- Appetite changes: Progesterone can increase appetite; some HRT regimens may affect hunger signals differently
- Water retention: Some HRT types cause fluid retention, which appears as weight gain but is not fat
Weight loss during HRT is still possible with a calorie deficit, but you may need to work slightly harder than before menopause. Use our free BMI calculator to track whether your weight is in a healthy range for your height, and our weight converter to monitor progress in stone, kg, or pounds.
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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.
Weight Loss Options Available in the UK
If you're on HRT and want to lose weight, several evidence-based approaches are recommended by the NHS. Lifestyle changes — including a reduced-calorie diet, regular physical activity, and behaviour change support — remain the foundation of sustainable weight management uk. The NHS offers free weight loss resources, including the NHS Weight Loss Plan and local weight management services.
For people with a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or cardiovascular disease, prescription weight loss medication may be suitable. These medications are prescribed alongside lifestyle changes, not instead of them. Your GP can assess whether you're eligible for NHS specialist weight management services or discuss private prescription weight loss options with you. Try our free GLP-1 weight loss calculator to explore how prescription medications might support your goals.
- 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 you take HRT and still lose weight?
Yes. Weight loss during HRT is possible with a consistent calorie deficit and regular activity, though it may require more effort than before menopause. HRT can actually support weight management by stabilising metabolism and reducing abdominal fat storage. Individual results vary based on HRT type, dosage, and how your body responds.
Does HRT cause weight gain?
HRT does not automatically cause weight gain. Some people gain weight on HRT, some maintain, and some lose weight. Weight changes depend on oestrogen dosage, progesterone type, diet, activity level, and individual metabolism. Fluid retention (which feels like weight gain) is common but is not fat gain and usually settles within weeks.
What prescription weight loss medication is available in the UK?
UK-licensed prescription weight loss medications include Wegovy (semaglutide), Mounjaro (tirzepatide), and Saxenda (liraglutide). These are available through NHS specialist services or private prescribing following a clinical assessment. They work by reducing appetite and supporting feeling fuller on smaller portions, alongside lifestyle changes.
Can you take weight loss injections while on HRT?
Some people do take both HRT and prescription weight loss medication. However, this is a personal medical decision that requires discussion with your GP or prescriber. They need to know your full medical history, current medications, and whether there are any individual interactions or considerations for your health.
What does the NHS recommend for weight loss during menopause?
The NHS recommends a combination of calorie reduction (aiming for 0.5–1 kg loss per week), regular physical activity (150 minutes moderate activity weekly), and behaviour change support. Your GP can refer you to local weight management services. For those who meet BMI criteria, prescription medication may be discussed as part of a comprehensive approach.
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.