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
Saxenda Injections For Weight Loss
Saxenda is a prescription-only weight loss injection licensed in the UK for adults with obesity or overweight with health conditions. Unlike the once-weekly injections Mounjaro and Wegovy, Saxenda is a daily GLP-1 receptor agonist that may help reduce appetite and support sustainable weight management alongside diet and exercise. This guide explains how Saxenda works, who may be eligible, and what to expect from treatment. Use our free BMI calculator above to check your starting point, and explore our GLP-1 weight loss calculator to see potential outcomes with different weight management approaches.
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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.
How Saxenda Works And UK Eligibility
Saxenda (liraglutide) is a GLP-1 receptor agonist — it mimics a natural hormone that helps regulate appetite and blood sugar. Unlike Mounjaro (which combines GIP and GLP-1) or Wegovy (once-weekly semaglutide), Saxenda is injected once daily and may help you feel fuller after smaller meals, reduce cravings, and slow how quickly food leaves your stomach.
UK eligibility: Saxenda may be prescribed if you have a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or cardiovascular disease. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may be eligible at BMI 27.5 or above due to higher health risks at lower BMI thresholds. You must be assessed by a prescriber — this is a prescription-only medicine.
- Once-daily injection (vs once-weekly for Mounjaro and Wegovy)
- Doses range from 0.6 mg to 3 mg per day
- Available through NHS specialist weight management services or private prescribing
- Requires clinical assessment before prescription
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.
Saxenda Doses, Side Effects, And Weight Loss Results
Saxenda dosing begins at 0.6 mg daily and escalates gradually over 4–5 weeks up to the target maintenance dose of 3 mg per day. Clinical trials showed that participants on Saxenda lost an average of approximately 5–6 kg, though individual results vary significantly — weight loss depends on adherence, diet, and exercise. Side effects are common, especially during dose escalation, and include nausea, diarrhoea, constipation, and stomach pain. Most side effects reduce as your body adjusts. Serious side effects are rare but include severe stomach pain (possible pancreatitis) or gallbladder problems — seek urgent medical attention if these occur.
Weight loss with Saxenda is typically achieved over 12–16 weeks as doses increase. The NHS recommends losing no more than 0.5–1 kg per week for sustainable results. Try our free progress tracker above to log your weight loss journey and stay motivated alongside your treatment plan.
- 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 is Saxenda different from Wegovy and Mounjaro?
Saxenda (liraglutide) is a daily injection with a single GLP-1 mechanism. Wegovy (semaglutide) is once-weekly and also single GLP-1. Mounjaro (tirzepatide) is once-weekly with dual GIP + GLP-1 action. Average weight loss differs — Saxenda ~5–6 kg, Wegovy ~15% body weight, Mounjaro ~15–21% body weight in clinical trials. Your GP or prescriber can advise which is most suitable for you.
Can I get Saxenda on the NHS in the UK?
Saxenda may be available through NHS specialist tier 3 weight management services if you meet eligibility criteria and have been referred by your GP. NHS availability varies significantly by region and waiting lists can be lengthy. Private online prescribing is also available through UK-licensed prescribers following an online clinical assessment — this is typically faster than NHS referral.
What are the main side effects of Saxenda?
Very common side effects include nausea, diarrhoea, vomiting, and constipation — most reduce as your body adjusts over weeks. Less common: headache, fatigue, injection site reactions, and decreased appetite. Serious but rare: severe stomach pain (pancreatitis), gallbladder problems, or allergic reactions. Always report persistent or severe side effects to your prescriber immediately.
How long does Saxenda take to work?
Saxenda works immediately but dose escalation takes 4–5 weeks to reach 3 mg. Noticeable appetite reduction typically starts within the first 1–2 weeks. Measurable weight loss usually appears over 4–8 weeks as doses increase. Full results are typically seen over 12–16 weeks. Individual timelines vary — some people respond faster than others.
Do I need to diet and exercise while using Saxenda?
Yes — Saxenda is prescribed alongside a reduced-calorie diet and increased physical activity. Clinical trials showed weight loss only when participants combined the injection with lifestyle changes. Saxenda helps control appetite and cravings, making it easier to stick to healthier eating patterns, but it is not a replacement for dietary and exercise changes.
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.