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
Is Sleep Apnoea Reversible With Weight Loss?
Yes, sleep apnoea can often improve or even reverse with sustained weight loss. Being overweight significantly increases the risk of obstructive sleep apnoea (OSA), as excess fat around the neck and throat narrows the airway. The NHS confirms that losing even 5–10% of body weight can noticeably reduce sleep apnoea symptoms. For some people, losing more substantial weight can lead to complete resolution of the condition. However, weight loss requires commitment to lifestyle changes, and for eligible adults in the UK, prescription weight management options are now available alongside diet and exercise.
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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 Sleep Apnoea
If you have sleep apnoea and struggle with traditional weight loss methods, prescription weight loss medications may help. Three main options are UK-licensed for weight management:
- Mounjaro (tirzepatide) — Dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed average weight loss of 15–21% body weight.
- Wegovy (semaglutide) — GLP-1 receptor agonist, once-weekly injection. Clinical trials demonstrated average weight loss of around 15% body weight.
- Saxenda (liraglutide) — GLP-1 receptor agonist, once-daily injection. Older option with established evidence for weight loss support.
These are prescription-only medications available in the UK for eligible adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (including sleep apnoea). Individual results vary considerably. Weight loss injections work best when combined with reduced-calorie diet and increased physical activity — not as a replacement for lifestyle changes. Our free GLP-1 weight loss calculator can help you estimate potential weight loss at different doses.
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 Access — How to Get Started
Access to prescription weight loss medication in the UK differs depending on your route:
- NHS route: Referral to tier 3 specialist weight management services from your GP. Availability and waiting lists vary significantly by region and ICB (Integrated Care Board). Some areas have substantial waiting times.
- Private route: Online consultation with a UK-licensed prescriber, followed by prescription from a GPhC-registered pharmacy. Available without NHS referral. Costs typically range from £129–£320 monthly depending on dose.
Start by discussing your sleep apnoea and weight with your GP. They can assess whether you are eligible and whether prescription weight loss treatment is appropriate for you. Use our free BMI calculator above to check your current BMI — this is the starting point for eligibility discussions. Your GP can also refer you to NHS weight management services if appropriate for your area.
- 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 weight loss is needed to improve sleep apnoea?
Even a 5–10% reduction in body weight can noticeably improve sleep apnoea symptoms according to NHS guidance. More substantial weight loss (15–20%) may lead to complete resolution of the condition. However, individual results vary based on the severity of sleep apnoea and other health factors. Your GP can discuss realistic targets for your situation.
Can sleep apnoea be supported by weight loss alone?
For many people, yes — sustained weight loss can reverse sleep apnoea completely. However, this depends on how much weight is lost, the severity of the condition, and individual anatomy. Some people may always require additional support even after weight loss. A GP or sleep specialist can assess your individual case and advise on the best approach.
How long does it take to see sleep apnoea improvement with weight loss?
Many people notice symptom improvement within 4–8 weeks of starting weight loss, though this varies. Prescription weight loss medications take several weeks to reach full effect at each dose level. Combining medication with diet and exercise changes, plus good sleep habits, typically produces the best results.
Am I eligible for prescription weight loss medication on the NHS for sleep apnoea?
You may be eligible if you have sleep apnoea as a weight-related comorbidity and meet BMI criteria (BMI 30+ or 27–29.9 with weight-related health conditions). Eligibility varies by region and NHS tier 3 service availability. Your GP can assess your individual eligibility and refer you if appropriate.
What happens to sleep apnoea if I stop taking weight loss medication?
If weight loss is sustained after stopping medication, sleep apnoea improvement typically remains. However, if weight is regained, sleep apnoea symptoms usually return. This is why weight loss medications are most effective when combined with lasting lifestyle changes — diet, physical activity, and sleep hygiene. Your prescriber can discuss the best long-term approach for your health.
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.