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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Red Light Therapy Belts for Weight Loss — What Works in the UK?
Red light therapy belts are marketed for weight loss, but evidence supporting their effectiveness is limited. If you're interested in weight management in the UK, prescription medications like Mounjaro and Wegovy have robust clinical evidence and NHS approval for eligible adults. This guide explains what red light therapy claims to do, why evidence is lacking, and what prescription weight loss options are actually available through the NHS and private prescribing. Understanding your options helps you make informed decisions with your GP about weight management that's backed by clinical research.
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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.
Prescription Weight Loss Options Available in the UK
If you're exploring weight loss options in the UK, prescription medications are evidence-based alternatives to unproven devices. Three medications are currently licensed for weight management:
- Mounjaro (tirzepatide) — a dual GIP and GLP-1 receptor agonist, once-weekly injection. Clinical trials showed an average weight loss of 15–21% body weight at the highest dose.
- Wegovy (semaglutide) — a GLP-1 receptor agonist, once-weekly injection. Clinical trials demonstrated approximately 15% average body weight loss.
- Saxenda (liraglutide) — a GLP-1 receptor agonist, once-daily injection. Evidence supports modest but sustained weight loss alongside lifestyle changes.
All three are prescription-only and require clinical assessment to determine eligibility. Use our free GLP-1 weight loss calculator to explore projected outcomes at different doses based on clinical trial data.
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 — How to Start Weight Management
NHS access: Referral to a tier 3 specialist weight management service from your GP. Availability varies by region and waiting times can be significant.
Private access: Online consultation with a UK-licensed prescriber, prescription issued if clinically appropriate, dispensed by a GPhC-registered pharmacy. Available without NHS referral.
Your eligibility depends on your BMI and health profile. Use our free BMI calculator to check your starting point, then discuss prescription weight loss options with your GP or a private prescriber. Both routes require clinical assessment — there is no one-size-fits-all solution, and individual results vary significantly.
- 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 red light therapy belts actually help with weight loss?
Red light therapy (low-level laser therapy) has limited evidence for weight loss. While some studies suggest potential benefits for skin and muscle recovery, robust clinical evidence for fat loss is lacking. Prescription GLP-1 medications like Mounjaro and Wegovy have far stronger clinical trial evidence and NHS approval.
What is the difference between red light therapy and prescription weight loss medication?
Red light therapy uses wavelengths of light; prescription medications work by mimicking natural hormones that regulate appetite. Clinical trials show GLP-1 medications produce measurable, significant weight loss (15–21%). Evidence for red light therapy's weight loss effects remains weak and unproven.
Am I eligible for prescription weight loss medication in the UK?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions (diabetes, high blood pressure, sleep apnoea). Check your BMI using our free BMI calculator, then speak with your GP or a private prescriber about eligibility and which option suits you.
What is the NHS position on red light therapy for weight loss?
The NHS does not routinely recommend red light therapy for weight loss due to insufficient clinical evidence. The NHS focuses on evidence-based interventions: tier 3 specialist services, behaviour change programmes, and prescription medications like Mounjaro and Wegovy for eligible adults.
How do I start prescription weight loss treatment on the NHS in the UK?
Ask your GP for a referral to a tier 3 specialist weight management service. They will assess your BMI, health history, and eligibility for medication. Alternatively, you can access private prescribing through an online UK-licensed prescriber. Either route requires clinical assessment before treatment begins.
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.