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
Can You Take Mounjaro If You've Had Your Gallbladder Removed?
If you've had your gallbladder removed and are considering Mounjaro (tirzepatide), it's important to understand how this GLP-1 medication may affect your health. A history of gallbladder removal doesn't automatically exclude you from taking Mounjaro, but your prescriber will need to assess your individual circumstances carefully. This guide explains what you need to know about Mounjaro eligibility after cholecystectomy (gallbladder removal) and how to discuss this with your GP or specialist in the UK.
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.
Gallbladder Removal and Mounjaro — What Your Prescriber Needs to Know
Mounjaro and gallbladder health are closely linked in clinical assessment. Your prescriber will want to know about any gallbladder problems because Mounjaro affects how your digestive system works — it slows gastric emptying and can influence bile flow and fat digestion. If you've already had your gallbladder removed via cholecystectomy, the main concern shifts from preventing gallstone formation to managing how Mounjaro affects your remaining digestive function.
Your UK prescriber or NHS specialist will review:
- How long ago your gallbladder was removed
- Why it was removed (gallstones, cholecystitis, or other reasons)
- Whether you experienced post-cholecystectomy syndrome (bile reflux, persistent pain, or digestive issues)
- Your current digestive symptoms and food tolerance
- Your liver function tests (LFTs) — these must be normal before starting Mounjaro
Having had your gallbladder removed doesn't mean you cannot take Mounjaro, but your prescriber needs complete information about your digestive history to assess suitability.
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 Prescribing and Pre-Mounjaro Assessment in the UK
Before your GP or NHS tier 3 specialist weight management service prescribes Mounjaro, you will have a full health assessment. You must declare any previous gallbladder surgery. Blood tests including liver function tests (LFTs) and pancreatic markers will be checked — these are standard baseline tests for anyone starting tirzepatide. If tests are abnormal or you have ongoing digestive symptoms post-cholecystectomy, your prescriber may recommend lifestyle adjustments first or suggest Mounjaro is not suitable at this time.
If you're eligible and your prescriber believes Mounjaro is appropriate, you'll receive a Mounjaro KwikPen and written information about monitoring. Report any new digestive symptoms — persistent stomach pain, nausea, or changes in bowel habits — to your GP immediately, as these need prompt assessment regardless of prior gallbladder surgery.
- 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.
Does having no gallbladder mean I can't take Mounjaro?
No — gallbladder removal doesn't automatically exclude you. However, your prescriber must assess your digestive function, symptoms, and liver tests before deciding if Mounjaro is suitable. Many people who've had their gallbladder removed do take Mounjaro safely, but individual circumstances vary.
What is post-cholecystectomy syndrome and does it affect Mounjaro eligibility?
Post-cholecystectomy syndrome refers to ongoing digestive symptoms like diarrhoea, cramping, or bile reflux after gallbladder removal. If you have active symptoms, your prescriber will want to assess whether Mounjaro might worsen these before prescribing. Stable, symptom-free patients are typically at lower risk.
What blood tests will my GP do before Mounjaro if I've had gallbladder surgery?
Standard pre-Mounjaro tests include liver function tests (LFTs), fasting blood glucose, and sometimes pancreatic enzyme markers (amylase, lipase). These establish baseline health and screen for any liver or pancreatic concerns that might affect safety — previous gallbladder surgery makes these checks especially important.
If I start Mounjaro and develop stomach pain, when should I contact my GP?
Contact your GP immediately if you experience severe, persistent upper abdominal pain spreading to your back — this could indicate pancreatitis. Mild nausea or constipation is common with Mounjaro, but severe pain needs urgent assessment regardless of your gallbladder history.
How do I access Mounjaro on the NHS if I've had my gallbladder removed?
You'll need referral from your GP to an NHS tier 3 specialist weight management service. At your assessment, declare your gallbladder surgery. If you meet NICE eligibility criteria (BMI ≥30 or ≥27 with weight-related conditions) and your specialist assesses you as suitable, Mounjaro can be prescribed with close monitoring.
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.