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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Easy Weight Loss Recipes and UK Prescription Options
Easy weight loss recipes are a great starting point for managing your weight, but for many people in the UK, prescription medication combined with dietary changes offers the most effective approach. If you're struggling with weight management, you may be eligible for prescription weight loss injections through the NHS or private prescribing. This guide explains the UK-licensed options available, how they work alongside lifestyle changes like healthy recipes, and how to find out if you're eligible for treatment.
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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-Licensed Prescription Weight Loss Options
Three prescription medications are currently licensed in the UK for weight management: Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). These are GLP-1 and GIP receptor agonist medications—not diet pills—that work by helping regulate appetite and supporting you to feel fuller after smaller meals.
Mounjaro and Wegovy are once-weekly injections; Saxenda is a daily injection. Clinical trials showed that adults using these medications, alongside a reduced-calorie diet and increased physical activity, lost an average of 15–21% of their body weight over one year. Individual results vary significantly.
- You must be aged 18 or over and have a BMI of 30 or above, or 27+ with weight-related health conditions like type 2 diabetes, high blood pressure, or heart disease
- All three require a prescription from a UK-licensed prescriber following a clinical assessment
- These medications work best combined with healthy eating and exercise—they're not a replacement for lifestyle changes
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 Access vs Private Prescribing in the UK
NHS access: Prescription weight loss medication is available through specialist tier 3 weight management services. You'll need a GP referral, and availability varies significantly by region. Waiting lists can be lengthy in many areas.
Private access: If you'd prefer not to wait, prescription weight loss medication is available through private online prescribing services. A UK-licensed prescriber will assess your eligibility via an online consultation, and your prescription is dispensed by a GPhC-registered pharmacy. Costs typically range from £129–£320 per month depending on dose.
To find out if you're eligible, check your BMI using our free BMI calculator, then speak to your GP about either NHS referral or discussing private options. Your GP can advise which route is best for your situation.
- 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.
Can I use weight loss medication instead of changing my diet?
No. Prescription weight loss medications like Mounjaro and Wegovy work best alongside dietary changes and increased physical activity. They support reduced appetite and help you eat smaller portions, but they're not a substitute for healthier eating habits. Think of them as a tool that makes lifestyle changes easier to stick to.
How quickly will I lose weight on prescription medication?
Weight loss varies between individuals. Clinical trials showed average weight loss of 15–21% over one year, but some people lose more and some lose less. The NHS recommends a safe rate of 0.5–1 kg per week. You should see initial changes within the first few weeks, though some people take longer to respond.
Are prescription weight loss injections available on the NHS in my area?
Availability varies significantly across UK regions. Contact your GP to ask about referral to your local tier 3 specialist weight management service. They can tell you whether the service is available in your area and what the waiting list timeframe is. Private prescribing is available nationwide without an NHS referral.
What's the difference between Mounjaro, Wegovy, and Saxenda?
All three are prescription-only weight loss medications. Mounjaro and Wegovy are once-weekly injections; Saxenda is a daily injection. Mounjaro is a dual GIP and GLP-1 agonist, while Wegovy and Saxenda are GLP-1 agonists only. Clinical evidence suggests similar weight loss outcomes, though individual response varies. Your prescriber will recommend which is most suitable for you.
Do I need to keep taking weight loss medication forever?
No. Once you reach a healthy weight, your prescriber will discuss the best approach—some people continue at a maintenance dose, others gradually reduce and stop. If you stop medication, maintaining your weight loss depends on continuing the lifestyle changes (healthy recipes, physical activity) you've adopted during treatment.
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.