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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Best Hypnosis for Weight Loss — UK Weight Management Options
Hypnotherapy is sometimes explored for weight management, but evidence for its effectiveness is mixed. If you're looking for proven weight loss support in the UK, prescription medications and lifestyle changes have stronger clinical backing. Adults with a BMI of 30 or above, or 25–29 with weight-related health conditions, may be eligible for NHS weight management services or prescription weight loss medication. This guide covers the most evidence-based approaches available to UK adults, including when to speak with your GP about prescription options for sustainable weight loss.
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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-Licensed Prescription Weight Loss Options
If you're interested in weight management support in the UK, several prescription weight loss medications are available following clinical assessment. These include Mounjaro (tirzepatide), a dual GIP and GLP-1 receptor agonist, and Wegovy (semaglutide), a GLP-1 agonist. Clinical trials have shown these medications may help adults lose an average of 15–21% of their body weight when combined with reduced-calorie diet and increased physical activity—though individual results vary significantly.
- Mounjaro: Once-weekly injection, starting dose 2.5 mg, maximum 15 mg. Average weight loss in trials: 15–21% body weight.
- Wegovy: Once-weekly injection, starting dose 0.25 mg, maximum 2.4 mg. Average weight loss in trials: approximately 15% body weight.
- Saxenda (liraglutide): Daily injection, maximum 3 mg. Longer-established option with solid clinical evidence.
All are prescription-only medicines requiring assessment by a licensed prescriber to determine suitability. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and check your BMI using our free calculator to see if you may be eligible.
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 Access vs Private Prescribing in the UK
NHS access to prescription weight loss medication is through specialist tier 3 and tier 4 weight management services. Your GP can refer you, but availability and waiting times vary significantly by region—some areas have lengthy waiting lists. Private access is available through GPhC-registered online prescribers following a remote clinical assessment, typically without an NHS referral.
To find out if you're eligible: calculate your BMI using the free tool on this page, then discuss with your GP or book a private assessment with a licensed prescriber. You'll need a BMI of 30 or above, or 27+ with weight-related conditions like type 2 diabetes, high blood pressure, or heart disease. Eligibility assessment considers your individual health, medications, and medical history.
- 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.
Is hypnosis proven to help with weight loss?
Hypnotherapy evidence for weight loss is limited and mixed. Some small studies suggest modest benefit when combined with lifestyle changes, but results are not assured. Prescription medications like Mounjaro and Wegovy have much stronger clinical trial evidence showing average weight loss of 15–21%, making them more reliable options if you're eligible.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are once-weekly injections, but they work slightly differently. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials suggest Mounjaro may produce slightly higher average weight loss (15–21% vs ~15%), but individual results vary. Your prescriber will advise which is suitable for you.
How do I get prescription weight loss medication on the NHS in the UK?
Ask your GP for a referral to your local specialist weight management service (tier 3). You'll be assessed on your BMI and any weight-related health conditions. However, NHS availability varies by region and waiting lists can be long. Private prescribing through online services is an alternative if you're eligible and prefer faster access.
Am I eligible for weight loss medication in the UK?
General eligibility includes BMI 30 or above, or 27–29 with weight-related conditions (type 2 diabetes, high blood pressure, heart disease, sleep apnoea). People of South Asian, Chinese, Black African, or Black Caribbean heritage may be eligible at lower BMI thresholds. Calculate your BMI using our free calculator and speak with your GP or a licensed prescriber for personalised advice.
How much weight can I realistically expect to lose?
Clinical trials showed average weight loss of 15–21% body weight with Mounjaro and approximately 15% with Wegovy over 12–24 months, alongside diet and exercise changes. However, individual results vary significantly—some people lose more, some less. Weight loss is not assured. Use our free GLP-1 weight loss calculator to explore potential projections based on your starting weight and medication dose.
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.