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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What Is a Healthy Muscle Percentage for Women?
Muscle percentage is the proportion of your body weight that is muscle tissue, rather than fat or bone. For women, healthy muscle percentage typically ranges from 30% to 40% of total body weight, though this varies with age, fitness level, and individual factors. Understanding your muscle composition is important because muscle supports metabolism, bone health, mobility, and overall fitness — alongside other measures like BMI. Our free BMI calculator and body composition tools can help you assess your overall health picture, but muscle percentage provides additional insight beyond simple weight or BMI measurements.
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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.
Healthy Muscle Percentage Ranges for Women
Reference ranges for women's muscle percentage vary by fitness level:
- Essential muscle: 10–13% — minimum for basic bodily functions
- Athletic: 21–24% — typical for women who exercise regularly
- Fitness: 25–30% — trained athletes and very active individuals
- Acceptable: 31–40% — healthy range for most adult women
- Above 40%: Very high muscle mass, typically seen in competitive athletes or strength trainers
These ranges account for differences in age, genetics, training history, and hormonal factors. A woman aged 20–40 might naturally carry 30–35% muscle, whilst women over 60 may have slightly lower ranges due to age-related muscle loss (sarcopenia). Unlike BMI, which does not distinguish between muscle and fat, muscle percentage gives a clearer picture of body composition quality. Use our free weight converter to track weight changes alongside muscle measurement for a complete view of your health journey.
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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.
How to Measure Muscle Percentage
Several methods exist to measure muscle percentage, ranging from highly accurate to practical home-based approaches:
- DEXA scan: Gold standard, uses low-dose X-rays, highly accurate, available through NHS specialist services or private clinics
- Bioelectrical impedance analysis (BIA): Portable scales or handheld devices send a small electrical current through the body; moderate accuracy, widely available
- Skinfold calipers: Measures fat at specific body sites; requires trained technician for accuracy
- 3D body scans: Advanced imaging, increasingly available at fitness centres; good accuracy
The most accessible method for most UK women is a BIA scale (available in supermarkets and online for £20–£100), though these are less accurate than DEXA. Your GP can refer you for professional assessment if body composition is relevant to your health care. Remember that muscle percentage changes gradually — aim for consistent measurement methods over time rather than comparing different methods.
- 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.
Why does muscle percentage matter more than just BMI?
BMI does not distinguish between muscle and fat, so two women with identical BMI can have very different body compositions. A woman with high muscle percentage and lower fat percentage may have a "high" BMI but be very fit, whilst another with the same BMI and lower muscle might have health concerns. Muscle percentage reveals what your weight actually consists of, supporting better health decisions alongside NHS health guidance.
How can women increase their muscle percentage?
Progressive resistance training (weights, resistance bands, or bodyweight exercises) 2–3 times weekly, combined with adequate protein intake (1.2–1.6g per kg body weight), is most effective. Building muscle takes weeks to months of consistent effort. Walking, running, or other cardio does not significantly increase muscle percentage — strength training is essential. Your GP or a registered nutritionist can personalise advice.
Is it normal for muscle percentage to decrease with age?
Yes. Women naturally lose 3–5% of muscle mass per decade after age 30, accelerating after 50. This age-related loss is called sarcopenia. Strength training and adequate protein can slow this loss significantly, even in older women. NHS guidelines recommend strength training for all age groups to maintain muscle, mobility, and bone density.
What is the difference between muscle percentage and muscle mass?
Muscle percentage is muscle as a proportion of total body weight. Muscle mass is the absolute amount of muscle tissue in kilograms. A 60kg woman with 35% muscle has 21kg of muscle; an 80kg woman with 35% muscle has 28kg of muscle. Both metrics matter — use our weight converter and BMI calculator to track changes alongside muscle percentage for a complete picture.
Can I measure muscle percentage at home?
Consumer BIA scales offer rough estimates (±3–5% accuracy), available for £20–£100. For clinical accuracy, DEXA scans (available privately or through NHS referral) are gold standard. BIA scales are convenient for tracking trends over time, but individual readings may not be precise. Consistency with the same device matters more than absolute accuracy for monitoring progress.
Ready to take control of your weight loss journey?
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