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
T5 Weight Loss Pills and UK Prescription Alternatives
T5 weight loss pills are no longer widely available in the UK market. However, if you're looking for effective weight management support, several prescription medications are now licensed in the UK for adults with a BMI of 30 or above, or 27 or above with weight-related health conditions. These modern options, including GLP-1 medications, have strong clinical evidence and are available through both NHS specialist services and private prescribing. This guide explains what's available, who is eligible, and how to access weight loss medication in the UK 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.
UK-Licensed Weight Loss Medications
The most effective prescription weight management options currently available in the UK include Mounjaro (tirzepatide), Wegovy (semaglutide), and Saxenda (liraglutide). Mounjaro is a dual GIP and GLP-1 receptor agonist that helps reduce appetite and support weight loss—clinical trials showed an average weight loss of 15–21% body weight over 72 weeks at maximum dose. Wegovy is a GLP-1 receptor agonist with an average weight loss of around 15% in clinical trials. Saxenda is a daily injection (rather than weekly) with similar mechanisms. All three are prescription-only medicines requiring assessment by a licensed prescriber. You'll need a BMI of 30 or above, or 27 or above if you have weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds (starting at 27.5) may apply due to higher health risks at lower weights.
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 in the UK
In the UK, prescription weight loss medication is available through two routes. NHS access is through specialist tier 3 weight management services—your GP can refer you, though waiting lists vary significantly by region and can be lengthy. Private access is through GPhC-registered online prescribing services where a UK-licensed prescriber assesses your eligibility following an online consultation, with no NHS referral needed. Weight loss medication works best alongside a reduced-calorie diet and increased physical activity. Use our free BMI calculator above to check your eligibility, and our GLP-1 weight loss calculator to explore potential outcomes. Speaking to your GP is always the first step—they can discuss which approach suits you best.
- 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.
Are T5 weight loss pills still available in the UK?
No, T5 weight loss pills are no longer widely available in the modern UK market. However, newer prescription weight loss medications like Mounjaro and Wegovy offer stronger evidence and are now licensed for weight management in the UK. These are prescription-only and require clinical assessment from a licensed prescriber.
What is the difference between Mounjaro and Wegovy for weight loss?
Mounjaro (tirzepatide) works on two hormone pathways (GIP and GLP-1) and showed average weight loss of 15–21% in trials. Wegovy (semaglutide) works on one pathway (GLP-1 only) with average weight loss around 15%. Both are once-weekly injections. Individual results vary, and your prescriber will advise which is most suitable.
How can I access weight loss medication on the NHS in the UK?
Ask your GP for a referral to a tier 3 specialist weight management service. Eligibility typically requires a BMI of 30 or above, or 27 or above with weight-related health conditions. NHS access varies by region and waiting lists can be long. Your GP can explain options specific to your area.
What does "BMI of 30 or above" mean in stone and pounds?
A BMI of 30 depends on your height. For example, at 5ft 8in (173cm), a BMI of 30 is approximately 90kg (14st 2lbs). Use our free BMI calculator above to find your personal BMI and eligibility threshold based on your height and weight.
Can I get weight loss injections privately without an NHS referral?
Yes. Private prescribing through GPhC-registered online services allows you to access weight loss medication following an online clinical assessment—no NHS referral needed. A UK-licensed prescriber will assess your eligibility, and if appropriate, issue a prescription dispensed by a registered pharmacy.
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.