Mounjaro vs Wegovy Calculator
Enter your weight and the monthly costs of each medication to compare projected weight loss, total spend, and cost per kilogram lost over your chosen timeframe.
Mounjaro (tirzepatide) and Wegovy (semaglutide) are the two main GLP-1/GIP weight-loss injections available privately in the UK. Both can be effective, but they differ in mechanism, cost, and expected outcomes.
This calculator helps you compare projected weight loss and total cost side-by-side, based on your own inputs and assumptions.
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What this calculator does
This calculator projects weight loss for both Mounjaro and Wegovy over your chosen timeframe using separate scenario assumptions. It compares monthly costs, total cost, projected weight loss, and cost per kilogram lost.
Who it is for
Adults in the UK who are deciding between Mounjaro and Wegovy for weight loss and want to compare the financial and weight-loss implications of each option.
How to use it
Enter your current weight and timeframe. Enter the monthly cost, consultation fee, and delivery fee for each medication. Choose a weight-loss scenario for each. Click 'See My Result' for a side-by-side comparison.
How the calculation works
We apply weekly percentage-based weight loss for each medication: Mounjaro (conservative 0.5%, moderate 0.75%, ambitious 1%) and Wegovy (conservative 0.4%, moderate 0.6%, ambitious 0.9%). These are simplified planning assumptions. Total cost includes monthly medication, consultation, and delivery fees.
Worked example
Starting at 95 kg, 6 months, Mounjaro at £150/month (moderate), Wegovy at £200/month (moderate): Mounjaro projected loss ≈ 11.4 kg, total cost ≈ £900, cost/kg ≈ £79. Wegovy projected loss ≈ 9.1 kg, total cost ≈ £1,200, cost/kg ≈ £132.
Assumptions and limitations
- Weight-loss rates are simplified planning assumptions, not clinical predictions
- Mounjaro slightly higher weekly rates reflect dual GLP-1/GIP mechanism and trial data showing higher average weight loss
- Costs reflect typical UK private prescription prices and may vary by provider
- Does not account for dose titration, supply issues, side effects, or treatment discontinuation
- This is for cost/outcome comparison planning only — medication choice should be made with a prescriber
Frequently asked questions
Is Mounjaro better than Wegovy?
Clinical trials suggest Mounjaro may produce greater average weight loss than Wegovy (up to 22.5% vs 15% body weight over 68–72 weeks). However, individual responses vary, and the best medication for you depends on your health profile, tolerance, and prescriber's assessment.
How much does Mounjaro cost in the UK?
Private Mounjaro prescriptions in the UK typically cost £100–£250 per month depending on the dose and provider. The NHS does not currently fund Mounjaro for weight loss in most areas (as of 2025).
How much does Wegovy cost in the UK?
Private Wegovy prescriptions typically cost £150–£300 per month depending on the provider and dose. NHS availability is limited and varies by region.
Can I switch between Mounjaro and Wegovy?
Switching between medications is possible but should always be done under medical supervision. Your prescriber can advise on the appropriate transition and dose adjustment.
Related calculators
- BMI Calculator for Mounjaro — Find your BMI, see which category it falls into, and understand how it relates to eligibility criteria for treatments like Mounjaro.
- Mounjaro Calorie Calculator — Calculate your maintenance calories and a safe deficit range to support steady weight loss alongside Mounjaro treatment.
- Mounjaro Calorie Deficit Calculator — Enter your maintenance calories and a target intake (or desired weekly loss) to see the size of your deficit and projected weight change ove
- Mounjaro Protein Calculator — Find out how much protein you should aim for each day and per meal to support muscle preservation during weight loss on GLP-1 medication.
- Mounjaro Weight Loss Calculator — This planning tool projects how much weight you could lose over a chosen number of weeks, using conservative, moderate, or ambitious assumpt
Related guides
- Mounjaro vs Wegovy for Weight Loss — A balanced comparison of Mounjaro (tirzepatide) and Wegovy (semaglutide) — mechanism, effectiveness, cost, and side effects.
- How Much Weight Can You Lose on Mounjaro? — A realistic look at expected weight loss on Mounjaro (tirzepatide), based on clinical trial data and practical planning advice.
- How Much Protein Should You Eat on Mounjaro? — Why protein matters during GLP-1 weight loss and how to hit your daily target with practical meal guidance.
- How Many Calories Should You Eat on Mounjaro? — Understanding your calorie needs during Mounjaro treatment — maintenance, deficit, and safe intake ranges explained.
- What BMI Means for Weight-Loss Injections — How BMI is used to assess eligibility for weight-loss medications like Mounjaro and Wegovy, and its limitations.
Sources and references
SURMOUNT-1 trial (tirzepatide), STEP trials (semaglutide), NICE TA1026, current UK private pharmacy pricing (as of April 2025)
Last updated
Last reviewed: 2025-04-12.