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
Flaxseed and Weight Loss — What the Evidence Shows
Flaxseed is often promoted as a natural aid for weight loss, but the evidence is modest. While flaxseed contains fibre and omega-3 fatty acids that may support satiety, clinical studies show only modest weight loss benefits — typically less than 2kg over several months. If you're looking to manage your weight in the UK, prescription weight management options are available through your GP, particularly if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions. This guide explains what flaxseed can and cannot do, and introduces evidence-based prescription alternatives available to eligible UK adults.
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.
UK-Licensed Prescription Weight Management Options
For adults seeking effective weight management in the UK, prescription medications offer significantly stronger evidence than dietary supplements like flaxseed. Three medications are currently licensed for weight management:
- Mounjaro (tirzepatide) — a dual GIP/GLP-1 injection. In clinical trials, participants lost an average of 15–21% of body weight over 72 weeks when combined with lifestyle changes.
- Wegovy (semaglutide) — a GLP-1 injection. Clinical trials showed approximately 15% average weight loss at the maximum dose over 68 weeks.
- Saxenda (liraglutide) — a daily GLP-1 injection. Average weight loss of around 5–8% body weight in trials.
All are prescription-only medicines requiring clinical assessment. Individual results vary significantly. These medications work alongside a reduced-calorie diet and increased physical activity — they are not replacements for lifestyle changes. Use our GLP-1 weight loss calculator to estimate potential weight loss at different doses, and our BMI calculator to check your starting point.
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.
Am I Eligible? NHS vs Private Access in the UK
You may be eligible for prescription weight loss treatment if you have a BMI of 30 or above, or a BMI of 27–29.9 with weight-related conditions such as type 2 diabetes, prediabetes, high blood pressure, or cardiovascular disease. Lower thresholds apply for people of South Asian, Chinese, Black African, or Black Caribbean heritage (BMI 27.5+).
NHS access: Through tier 3 specialist weight management services — referral from your GP required. Availability and waiting times vary by region.
Private access: Through UK-licensed online prescribers following a clinical assessment. No NHS referral needed. Faster access but at private cost.
Speak to your GP about eligibility, or use our BMI calculator above to check your starting weight category. Your GP can advise on NHS pathways in your area.
- 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 flaxseed actually help with weight loss?
Limited evidence suggests flaxseed's fibre and omega-3 content may support satiety slightly, but clinical studies show only modest benefits — typically 1–2kg loss over several months, often similar to placebo. It may support general health but is not a weight loss treatment.
How much weight can I expect to lose with Mounjaro or Wegovy?
In clinical trials, Mounjaro led to average weight loss of 15–21% of body weight, and Wegovy around 15%, over approximately 68–72 weeks alongside lifestyle changes. Individual results vary significantly — some people lose more, others less. Your prescriber can discuss realistic expectations for you.
How do I get Mounjaro or Wegovy on the NHS?
Ask your GP for a referral to your local tier 3 specialist weight management service. They will assess your eligibility based on BMI and weight-related health conditions. Availability and waiting times vary by region (ICB). Private options are also available through licensed UK online prescribers.
Is prescription weight loss medication safe?
All three UK-licensed medications undergo rigorous safety testing. Side effects are generally mild to moderate (nausea, diarrhoea) and often improve over time. Serious side effects are rare but do occur. Your prescriber will assess whether treatment is safe for you and monitor progress.
Can I combine flaxseed with prescription weight loss medication?
Flaxseed is unlikely to interact with Mounjaro, Wegovy, or Saxenda. However, always inform your prescriber of all supplements you take. Your GP or prescriber can advise on what's safe to combine with your prescribed medication.
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.