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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No Alcohol and Weight Loss — Prescription Weight Management in the UK
Cutting out alcohol can support your weight loss efforts — alcoholic drinks contain calories that quickly add up, and reducing intake may help you achieve a calorie deficit more easily. If you're considering a structured approach to weight management, the UK offers several prescription medication options alongside lifestyle changes like reducing alcohol consumption. Understanding what's available and whether you're eligible is the first step towards achieving sustainable results.
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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
For adults looking to lose weight through medication in the UK, three prescription options are currently licensed: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). All work by activating appetite-regulating hormones in the body. Mounjaro is a dual GIP and GLP-1 receptor agonist given as a once-weekly injection, whilst Wegovy is a GLP-1 agonist also given once weekly. Clinical trials showed Mounjaro helped participants lose an average of 15–21% of their body weight, and Wegovy around 15%, though individual results vary significantly.
- All three medications are prescription-only and require clinical assessment before prescribing
- Eligibility requires a BMI of 30 or above, or 27 or above with weight-related health conditions such as type 2 diabetes or high blood pressure
- For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply
- These medications work alongside reduced-calorie diet and increased physical activity — they are not replacements for lifestyle changes
Using our free GLP-1 weight loss calculator above can help you estimate potential results at different medication doses and see how alcohol reduction might contribute to your overall weight loss strategy.
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 and How to Find Out If You're Eligible
In the UK, prescription weight loss medication is available through both NHS specialist services and private online prescribing. NHS access requires referral from your GP to a tier 3 specialist weight management service — availability varies significantly by region, and waiting lists can be substantial. Private access is available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber, with no NHS referral needed.
To find out if you're eligible, start by calculating your BMI using our free BMI calculator on this page — this gives you a clear starting point. Then speak with your GP about your weight loss goals and the options available in your area. Your GP can assess whether prescription medication is appropriate for you and discuss how reducing alcohol, alongside other lifestyle changes, fits into your overall weight management plan.
Combining prescription weight management with alcohol reduction can be particularly effective, as alcohol provides empty calories without nutritional benefit. Many people find that removing or significantly reducing alcohol intake naturally reduces overall calorie consumption and may improve sleep quality and energy levels — both factors that support sustainable weight loss. Track your progress with our free progress tracker to see the cumulative effect of both alcohol reduction and other lifestyle changes over time.
- 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.
Does alcohol directly prevent weight loss, or is it just about calories?
Alcohol contains calories that can quickly add up — a standard glass of wine is around 120 calories, and alcohol can also increase appetite and reduce willpower around food choices. Beyond calories, alcohol may slow metabolism slightly and interfere with fat burning. Cutting alcohol typically makes achieving a calorie deficit easier.
Can I take Mounjaro or Wegovy if I drink alcohol occasionally?
There is no absolute contraindication to occasional alcohol use with GLP-1 or GIP/GLP-1 medications, but alcohol can increase nausea and gastrointestinal side effects, which are already common with these medications. It's important to discuss your alcohol consumption with your prescriber, who can give you personalised guidance based on your health.
How long does it take to see weight loss results if I stop drinking alcohol?
Results vary, but many people notice initial changes within 1–2 weeks as they create a calorie deficit. Sustainable weight loss is typically 0.5–1 kg per week according to NHS guidance. The rate depends on your starting weight, overall calorie intake, physical activity, and individual metabolism.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist that may produce slightly larger average weight losses (15–21%) compared to Wegovy (semaglutide, a GLP-1 agonist only, averaging around 15%). Both are once-weekly injections, prescription-only, and require clinical assessment. Your prescriber will advise which is more suitable for you.
Can I access prescription weight loss medication through the NHS if I can't afford private?
Yes — your GP can refer you to your local NHS tier 3 specialist weight management service. You don't need to pay, but you will likely need to be on a waiting list, which varies by region. Discuss your options with your GP, including whether private access might be faster in your area if that's feasible for you.
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.