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
Liraglutide Weight Loss — How Saxenda Works in the UK
Liraglutide is a prescription-only weight loss medication sold as Saxenda in the UK. It's a GLP-1 receptor agonist that works by reducing appetite and helping you feel fuller after smaller meals. Unlike newer GLP-1 injections like Wegovy, liraglutide is a daily injection rather than weekly. It's licensed for weight management in UK adults with a BMI of 30 or above, or 27 or above with weight-related health conditions. Individual results vary, and it's used alongside dietary changes and increased physical activity. Our free GLP-1 weight loss calculator can help you explore potential outcomes with prescription weight loss medication.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Liraglutide Works for Weight Loss
Liraglutide mimics GLP-1, a natural hormone that regulates appetite and blood sugar. When you inject Saxenda daily, it activates GLP-1 receptors in your brain, signalling satiety and reducing hunger cues. This helps you eat less without feeling deprived.
- Slows how quickly food leaves your stomach (gastric emptying)
- Reduces cravings and food preoccupation
- Supports steady blood sugar levels
- Works best with a reduced-calorie diet and exercise
Clinical trials showed liraglutide helped participants lose an average of 5–10% of their body weight over 56 weeks. However, weight loss varies significantly between individuals — some lose more, some less. Your GP or prescriber can assess whether liraglutide is suitable for your individual circumstances.
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.
Liraglutide Doses, Access, and Side Effects in the UK
Saxenda doses range from 0.6 mg to 3 mg daily. Treatment starts at 0.6 mg and increases weekly until reaching the maintenance dose of 3 mg. Each pen lasts one week, so you'll need seven pens per month at full dose.
Access in the UK: Liraglutide is available through NHS specialist weight management services (tier 3) and private online prescribing. NHS access requires GP referral and varies significantly by region. Private prescribers can issue prescriptions following an online assessment. Common side effects include nausea, diarrhoea, and constipation — most improve over time. Use our BMI calculator to check your eligibility, and track your progress with our free progress tracker if you start treatment.
- 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 does liraglutide differ from Wegovy?
Both are GLP-1 receptor agonists, but liraglutide (Saxenda) is a daily injection up to 3 mg, while Wegovy (semaglutide) is once-weekly up to 2.4 mg. Clinical trials suggest semaglutide may produce slightly greater average weight loss. Both are prescription-only and require clinical assessment. Individual response varies.
Is liraglutide available on the NHS?
Yes, liraglutide is available through NHS specialist tier 3 weight management services, but availability and waiting times vary significantly by region and clinical commissioning group. Your GP can refer you. Private access is also available through UK-licensed online prescribers following a clinical consultation.
What's the typical weight loss with liraglutide?
Clinical trials showed average weight loss of 5–10% of body weight over 56 weeks alongside diet and exercise. Results vary considerably between individuals. Some people lose more, others less. Your prescriber can discuss realistic expectations based on your circumstances.
How often do I inject liraglutide?
Liraglutide (Saxenda) is injected once daily, unlike Wegovy which is once weekly. Each pre-filled pen lasts seven days. You'll need approximately four pens per week at the full 3 mg maintenance dose.
What are the main side effects of liraglutide?
Very common side effects include nausea, diarrhoea, constipation, and stomach pain. Most side effects are mild and improve over time as your body adjusts. Serious side effects are rare. Always discuss concerns with your GP or 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.