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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GLP-1 Weight Loss Oral Solution UK
GLP-1 weight loss treatments are available in the UK, but currently they are all delivered as injectable medications rather than oral solutions. Semaglutide (Wegovy) and tirzepatide (Mounjaro) are the main prescription weight loss options available to UK adults, both administered as once-weekly injections. This guide explains how GLP-1 medications work, UK eligibility, and what to expect from weight management through prescription treatment alongside lifestyle changes.
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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.
How GLP-1 Medications Work for Weight Loss
GLP-1 (glucagon-like peptide-1) is a natural hormone your body produces after eating. It signals to your brain that you're satisfied, helping regulate appetite and food intake. GLP-1 receptor agonist medications mimic and amplify this effect, which is why they're effective for weight management.
In the UK, two main prescription options are available:
- Wegovy (semaglutide) — a once-weekly injection that works via GLP-1 mechanism alone, with clinical trials showing average weight loss of around 15% of body weight
- Mounjaro (tirzepatide) — a once-weekly injection that activates both GLP-1 and GIP receptors (dual mechanism), with clinical trials showing average weight loss of 15–21% of body weight
Both medications help reduce appetite, support feeling fuller after meals, and slow gastric emptying. They are prescription-only and require a clinical assessment before being prescribed. Results vary significantly between individuals, and medications are most effective when combined with reduced-calorie diet and increased physical activity.
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.
UK Eligibility and How to Access Weight Loss Treatment
In the UK, you may be eligible for prescription weight loss medication if you have a BMI of 30 or above, or 27–29.9 with at least one weight-related health condition such as type 2 diabetes, high blood pressure, or sleep apnoea. Lower BMI thresholds (from 27.5) apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage.
Access is available through two routes: NHS specialist weight management services (tier 3), which typically require GP referral but can involve waiting lists, or private prescription through a UK-licensed prescriber following an online clinical assessment. Calculate your BMI using our free BMI calculator above, and try our GLP-1 weight loss calculator to estimate potential results at different doses.
Important: There are currently no oral GLP-1 solutions licensed for weight loss in the UK. All prescription weight loss GLP-1 medications are injectable. Some semaglutide oral tablets exist internationally for diabetes management, but these are not licensed in the UK for weight loss and are not available through UK prescriptions for this indication. Always consult your GP or a licensed prescriber about what options are available and appropriate for your individual circumstances.
- 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 there an oral GLP-1 weight loss medication available in the UK?
Currently, no oral GLP-1 solutions are licensed for weight loss in the UK. Wegovy (semaglutide) and Mounjaro (tirzepatide) — the main prescription weight loss options — are both delivered as once-weekly injections. Oral semaglutide exists for diabetes management but is not licensed for weight loss in the UK.
How much weight can I expect to lose with GLP-1 medication?
Clinical trials show average weight loss of 15–21% of body weight over several months, depending on the medication and dose. However, individual results vary significantly. Weight loss is achieved alongside a reduced-calorie diet and increased physical activity. Your GP or prescriber can discuss realistic expectations for your situation.
What's the difference between Wegovy and Mounjaro for weight loss?
Both are prescription weight loss injections given once weekly. Wegovy (semaglutide) is a GLP-1 agonist, while Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist. Clinical trials suggest Mounjaro may produce slightly greater average weight loss, but both are effective. Your prescriber will assess which is more suitable for you.
Can I get GLP-1 weight loss medication on the NHS?
Yes, NHS specialist weight management services (tier 3) can prescribe GLP-1 medications like Mounjaro and Wegovy for eligible adults. However, access varies significantly by region and waiting lists can be lengthy. Private prescription through a licensed prescriber is an alternative option available without NHS referral.
What side effects should I expect with GLP-1 injections?
Common side effects include nausea, diarrhoea, constipation, and stomach discomfort, particularly when starting or increasing doses. Most side effects are mild to moderate and often improve over time. Serious side effects are rare but can include severe abdominal pain (possible pancreatitis) — seek medical attention immediately if this occurs.
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.