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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Does Chia Seeds Help Weight Loss? Evidence and UK Options
Chia seeds are often promoted as a weight loss aid, but the evidence is modest. While they're nutritious and high in fibre, they won't cause significant weight loss on their own. If you're looking for effective weight management in the UK, there are prescription options available for eligible adults — including GLP-1 injections like Mounjaro and Wegovy. This guide covers what chia seeds actually do, and explores evidence-based approaches to weight loss that may be more effective for your situation.
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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 Prescription Weight Loss Options
If you're struggling with weight management in the UK, prescription medications may be available to you. Three main options are licensed for weight loss:
- Mounjaro (tirzepatide) — a dual GIP/GLP-1 injection that may help reduce appetite and support feeling fuller. Clinical trials showed an average weight loss of 15–21% of body weight over 72 weeks, though individual results vary.
- Wegovy (semaglutide) — a GLP-1 injection administered once weekly. Evidence from trials showed an average weight loss of around 15% of body weight, alongside a reduced-calorie diet and increased activity.
- Saxenda (liraglutide) — a daily GLP-1 injection, with an average weight loss of around 5–10% of body weight.
You may be eligible for prescription weight loss medication 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, high blood pressure, or sleep apnoea. Use our free BMI calculator above to check your personal BMI and understand where you fall on the NHS scale.
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.
How to Access Weight Loss Support in the UK
You have two main routes to weight loss medication in the NHS and private settings:
- NHS route: Ask your GP for a referral to your local specialist weight management service (tier 3). They will assess your eligibility and can prescribe medication alongside support. Availability varies by region and waiting times can be lengthy.
- Private route: You can access prescription weight loss injections through a GPhC-registered online pharmacy following a clinical assessment. This doesn't require an NHS referral and is often faster, though there is a cost.
Our free GLP-1 weight loss calculator can help you estimate potential results at different doses, giving you a clearer picture of what to discuss with your GP or prescriber. Whether you choose chia seeds as part of a balanced diet or explore prescription options, sustainable weight loss works best when combined with dietary changes and physical activity.
- 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 chia seeds actually help with weight loss?
Chia seeds are high in fibre and absorb liquid, which may help you feel fuller for longer. However, evidence for significant weight loss from chia seeds alone is limited. They're a nutritious addition to a balanced diet, but won't cause meaningful weight loss without a calorie deficit and lifestyle changes.
What's the difference between Mounjaro and Wegovy for weight loss?
Both are prescription-only once-weekly injections. Mounjaro is a dual GIP/GLP-1 agonist with an average weight loss of 15–21%, while Wegovy is a GLP-1 agonist with an average weight loss of around 15%. Both require a clinical assessment. Individual results vary significantly.
Can I get prescription weight loss medication through the NHS?
Yes, if you meet the criteria (BMI ≥30, or ≥27.5 with weight-related health conditions). Ask your GP for a referral to a specialist weight management service. Availability and waiting times vary by region. Private access is also available through online prescribing without an NHS referral.
How quickly do prescription weight loss injections work?
Results typically appear over weeks to months. Most people notice changes in appetite within the first few weeks, with measurable weight loss becoming apparent after 4–8 weeks. The dose is gradually increased over time to find the right level for you.
Are there side effects with GLP-1 weight loss injections?
Common side effects include nausea, diarrhoea, and constipation, especially when starting or increasing the dose. These often improve over time. Serious side effects are rare but can include pancreatitis. Always discuss side effects with your prescriber if they persist.
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.