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 Weight Loss: UK Prescription Medication Options
If you're considering cutting alcohol to support weight management, prescription medications may also help. In the UK, several weight loss injections are available through NHS specialist services or private prescribing for eligible adults. This guide covers the main options, how they work, and how to find out if you qualify. Weight management uk approaches include both lifestyle changes and medical support — your GP can help you explore what's right for you.
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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 Medications
Three prescription weight loss injections are licensed in the UK for adults with excess weight or weight-related health conditions:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, once weekly, doses 2.5–15 mg. Clinical trials showed average weight loss of approximately 15–21% of body weight over 72 weeks alongside reduced-calorie diet and increased physical activity.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, once weekly, maximum dose 2.4 mg. Average weight loss approximately 14.9% of body weight in clinical trials.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, once daily injection, maximum dose 3 mg. Established option with longer history of use.
All are prescription-only medicines requiring clinical assessment. Individual results vary significantly. Use our free GLP-1 weight loss calculator above to explore projected outcomes 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 and Eligibility
In the UK, weight loss medication nhs access is through specialist tier 3 weight management services following GP referral — availability varies significantly by region and waiting lists can be lengthy. Prescription weight loss treatment is available privately through UK-licensed prescribers following an online clinical assessment, without NHS referral.
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions (type 2 diabetes, high blood pressure, heart disease, sleep apnoea). South Asian, Chinese, Black African, and Black Caribbean adults may be eligible at lower BMI thresholds. Check your personal BMI using our free BMI calculator above, then speak to your GP about next steps — they can advise on both NHS and private options suitable for your health profile.
- 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.
Do I need to stop drinking alcohol completely to use weight loss medication?
No. Prescription weight loss medications like Mounjaro and Wegovy don't require complete alcohol abstinence. However, alcohol is high in calories and may reduce the effectiveness of weight loss efforts. Your prescriber will advise on safe alcohol consumption with your specific medication. Combining medication with reduced alcohol intake and a calorie-controlled diet typically gives the best results.
Can weight loss medication replace lifestyle changes like reducing alcohol?
No. Prescription medications are most effective alongside lifestyle changes, not instead of them. This includes dietary modifications, increased physical activity, and reducing excess calories from alcohol or other sources. Clinical trials showed weight loss medication worked best when combined with a reduced-calorie diet and exercise programme — medication supports but doesn't replace these changes.
How do I find out if I'm eligible for prescription weight loss medication on the NHS?
Start by speaking to your GP. They can assess your BMI, health history, and weight-related conditions to determine if you meet NHS eligibility criteria. If eligible, you'll be referred to a specialist weight management service (tier 3), where a multidisciplinary team will conduct a full assessment. Waiting times vary by region — some areas have lengthy lists. Your GP can also discuss private options if you prefer faster access.
What's the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist with clinical trial results showing slightly higher average weight loss (15–21%) compared to Wegovy (approximately 14.9%). Mounjaro starts at a lower dose (2.5 mg) and has a higher maximum (15 mg), while Wegovy starts at 0.25 mg up to 2.4 mg. Both are once-weekly injections. Both work best alongside diet and exercise — individual results vary.
Can I get weight loss injections privately if I don't qualify for the NHS?
Yes. Private prescribing through UK-licensed online prescribers is available to eligible adults who meet the prescriber's clinical criteria — you don't need an NHS referral. Following an online assessment, a prescriber may issue a prescription if appropriate. This is dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on dose and provider. Always ensure you're using a registered UK prescriber.
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.