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
Does sleeping help with weight loss?
Yes, sleep plays an important role in weight management. Poor sleep disrupts hunger hormones, increases appetite, and slows metabolism—making weight loss harder. However, sleep alone won't cause significant weight loss. For effective weight management in the UK, most people need a combination of improved sleep, reduced-calorie diet, increased physical activity, and sometimes prescription medication. If you're struggling with your weight, our free BMI calculator can help you understand your current health status, and your GP can discuss weight management options tailored to 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.
How sleep affects weight management
Sleep influences weight loss through several biological mechanisms. When you sleep poorly, your body produces less leptin (the hormone that signals fullness) and more ghrelin (the hunger hormone), leading to increased appetite and food cravings. Poor sleep also slows metabolic rate, meaning your body burns fewer calories at rest. Studies show adults sleeping fewer than 6 hours per night are at higher risk of overweight and obesity.
- Aim for 7–9 hours of quality sleep nightly for optimal metabolism
- Poor sleep increases cravings for high-calorie, sugary foods
- Sleep deprivation raises cortisol levels, promoting fat storage around the abdomen
- Regular sleep patterns help regulate appetite hormones more effectively
While better sleep can support weight loss, it works best alongside other strategies like a balanced diet and physical activity. For eligible adults, prescription weight loss medication available through NHS weight management services or private prescribing may also help, particularly for those with a BMI of 27 or above with weight-related health conditions.
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.
Prescription weight loss options in the UK
If sleep improvement and lifestyle changes aren't enough, prescription weight loss injections may be suitable for eligible UK adults. Mounjaro (tirzepatide) and Wegovy (semaglutide) are GLP-1 medications licensed for weight management. Both work by reducing appetite and helping you feel fuller after smaller meals. Clinical trials show these medications may support average weight losses of 15–21% body weight when combined with diet and exercise.
- Available through NHS specialist tier 3 weight management services (eligibility varies by region)
- Also available privately through GPhC-registered online prescribers following clinical assessment
- Require BMI of 30 or above, or 27 or above with weight-related health conditions
- Individual results vary—prescription required before use
Speak with your GP about your weight management goals. They can assess whether prescription medication is appropriate for you or refer you to specialist services.
- 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.
How much does sleep affect weight loss?
Sleep significantly impacts weight through hunger hormones and metabolism. Poor sleep can increase appetite by 20–30%, making weight loss considerably harder. However, sleep is one factor among many—you'll also need a calorie deficit and physical activity for meaningful weight loss. Our free BMI calculator shows whether your current weight puts you at increased health risk.
Can better sleep alone help me lose weight?
Better sleep will support weight loss efforts, but it's unlikely to cause significant weight loss on its own. Most effective weight management combines good sleep, reduced calories, increased activity, and sometimes medical support. If you have a BMI over 27 with health concerns, speak to your GP about weight management options available in the UK.
What's the best sleep schedule for weight loss?
Aim for 7–9 hours nightly with consistent bed and wake times. Avoid screens 1 hour before bed, keep your bedroom cool and dark, and avoid caffeine after 2 PM. Regular sleep patterns help stabilise appetite hormones more effectively than irregular sleep, even if total hours are the same.
Are weight loss injections available on the NHS?
Yes, Mounjaro and Wegovy are available through NHS specialist tier 3 weight management services, though availability and waiting times vary significantly by region. Private online prescribing is also available following clinical assessment. Your GP can discuss eligibility and next steps based on your BMI and health conditions.
What's the connection between sleep and hunger?
Sleep deprivation reduces leptin (fullness hormone) and increases ghrelin (hunger hormone). This hormonal shift makes you feel hungrier and less satisfied after eating. Poor sleep also triggers cravings for high-calorie foods. Consistently getting 7–9 hours helps regulate these hormones naturally, supporting your weight management UK goals.
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.