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
Orlistat Weight Loss Reviews — What You Need to Know
Orlistat is a prescription weight management medication available on the NHS in the UK, but many people are now exploring newer alternatives like GLP-1 injections that may offer better results. If you're researching orlistat or considering prescription weight loss options, it's helpful to understand how different medications compare, who qualifies, and what the latest evidence shows. This guide covers orlistat reviews, how it works, and the wider range of prescription weight management choices available to eligible UK adults today.
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.
Current Prescription Weight Loss Options Available in the UK
The UK now has several prescription weight management options beyond orlistat. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist that clinical trials showed helped participants lose an average of 15–21% of body weight — significantly more than orlistat in many cases. Wegovy (semaglutide) is a GLP-1 injection that produced average weight loss of around 15% in clinical trials. Saxenda (liraglutide) is a daily GLP-1 injection also licensed for weight management in the UK.
Orlistat (Xenical, Beacita) works differently — it reduces fat absorption in the digestive system rather than affecting appetite. Many patients report orlistat reviews highlight gastrointestinal side effects as a limiting factor. In contrast, modern GLP-1 and GLP-1/GIP medications work on appetite regulation and are taken once weekly (or daily for Saxenda), which many find more convenient. A free GLP-1 weight loss calculator on this page can help you compare projected results at different doses of newer medications.
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 Eligibility and How to Get Prescription Weight Loss Treatment
To access prescription weight loss medication on the NHS, you need a BMI of 30 or above, or 27–29.9 with a weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may qualify at slightly lower BMI thresholds due to higher health risk. Access is through your GP, who may refer you to a specialist tier 3 weight management service.
Waiting times for NHS specialist services vary significantly by region — in some areas, waits can be several months or longer. Private prescription weight loss treatment is also available through licensed UK prescribers without NHS referral. Check your BMI using our free BMI calculator above to see if you meet eligibility criteria, then speak with your GP about your options.
- 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 does orlistat compare to newer weight loss injections like Mounjaro?
Orlistat works by reducing fat absorption in the digestive system, while Mounjaro is a GLP-1/GIP injection that reduces appetite. Clinical trials show Mounjaro produces greater average weight loss (15–21% vs 5–7% for orlistat). Mounjaro is injected once weekly; orlistat requires multiple daily capsules. Mounjaro side effects differ from orlistat's gastrointestinal effects. Individual results vary, and suitability depends on your health profile and GP assessment.
What do orlistat weight loss reviews typically say about side effects?
Common orlistat reviews mention gastrointestinal side effects including fatty stools, urgency, and digestive discomfort — especially after high-fat meals. These occur because orlistat prevents fat absorption. Many people find these side effects limiting over time, which is why some prefer newer alternatives. Always discuss potential side effects with your GP before starting any weight loss medication.
Can I get orlistat on the NHS in the UK?
Yes, orlistat is available on the NHS as part of weight management services, though it's increasingly being replaced by newer medications in many areas. Your GP can prescribe it or refer you to a specialist weight management service. Availability and prescribing preferences vary by NHS region (ICB). Discuss your options with your GP to see what's available locally.
What qualifies you for prescription weight loss medication in the UK?
You may qualify if your BMI is 30 or above, or 27–29.9 with a weight-related health condition like diabetes, high blood pressure, sleep apnoea, or cardiovascular disease. Use our free BMI calculator above to check your BMI. Ethnicity-adjusted thresholds apply for certain groups. Your GP will assess whether you're eligible and which medication is most suitable.
Should I choose orlistat or try a newer weight loss injection?
This depends on your individual health, preferences, and GP recommendation. Newer medications like Mounjaro and Wegovy typically produce greater weight loss in clinical trials but have different side effects. Orlistat has a longer track record. Your GP will assess your medical history and recommend the most appropriate option. A free GLP-1 weight loss calculator can help you compare projected outcomes with newer medications.
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.