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
MCT Oil For Weight Loss — UK Prescription Weight Management Guide
MCT oil is a dietary supplement sometimes marketed for weight loss, but evidence for weight loss is limited. If you're looking for medically-supported weight management in the UK, prescription medications are available for eligible adults. GLP-1 receptor agonists like Mounjaro (tirzepatide) and Wegovy (semaglutide) are licensed prescription options that work differently from food supplements and have stronger clinical evidence. This guide explains what's available through the NHS and privately, and how to find out if you might be eligible.
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 evidence-based weight management in the UK, prescription medications offer a clinically-supported approach alongside diet and exercise. Three medicines are currently licensed for weight loss:
- Mounjaro (tirzepatide) — a once-weekly injection that activates GLP-1 and GIP hormone pathways. In clinical trials, participants lost an average of 15–21% of body weight over 72 weeks alongside a reduced-calorie diet.
- Wegovy (semaglutide) — a once-weekly GLP-1 injection. Clinical trials showed average weight loss of approximately 15% of body weight at the highest dose.
- Saxenda (liraglutide) — a daily GLP-1 injection, with average weight loss around 5–10% of body weight.
All are prescription-only medicines requiring clinical assessment. Eligibility typically includes adults with a BMI of 30 or above, or BMI 27 or above with weight-related health conditions such as type 2 diabetes or hypertension. Individual results vary significantly. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses.
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 Prescription Routes
NHS access to prescription weight loss medication is through specialist tier 3 weight management services, typically requiring GP referral. Availability varies significantly across regions, and waiting lists can be lengthy. Private access is available through UK-licensed online prescribers following a clinical assessment, without requiring NHS referral.
To find out if prescription weight management might be right for you, start by checking your BMI using our free BMI calculator. Then speak with your GP, who can discuss your options and assess your individual circumstances. If you prefer private consultation, you can contact a registered online prescriber directly. Either way, any prescription requires a proper clinical evaluation — your health history, current medications, and personal goals all matter.
- 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.
Is MCT oil effective for weight loss?
MCT oil (medium-chain triglyceride oil) is a food supplement with limited clinical evidence for weight loss. Some studies suggest modest metabolic effects, but results are inconsistent and weight loss is typically minimal. It is not a prescription medication and has no regulatory approval for weight management.
What's the difference between MCT oil and GLP-1 weight loss injections?
MCT oil is a dietary supplement with weak evidence. GLP-1 medications like Mounjaro and Wegovy are prescription medicines with robust clinical trial data showing 15–21% average weight loss. They work by regulating appetite hormones, while MCT oil affects fat metabolism minimally.
Can I get prescription weight loss medication on the NHS in the UK?
Yes, if eligible. NHS prescription weight loss medications are available through specialist weight management services (tier 3), typically after GP referral. Eligibility includes BMI 30+ or BMI 27+ with weight-related health conditions. Regional availability and waiting times vary significantly.
What is the fastest way to access prescription weight loss medication in the UK?
Private online prescribing is typically faster than NHS routes. You can have a clinical assessment with a UK-licensed prescriber without NHS referral, usually within days. NHS specialist services may involve longer waits depending on your region and ICB (Integrated Care Board) capacity.
How do I know if I'm eligible for prescription weight loss treatment?
Use our free BMI calculator to check your starting point. General eligibility includes BMI 30 or above, or BMI 27–29 with weight-related conditions like diabetes or hypertension. Your GP can assess your individual eligibility, or an online prescriber will evaluate you during a private consultation.
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.