How often should you inject Mounjaro?

Mounjaro is typically injected once weekly due to its long half-life of approximately 5 days.

How long until Mounjaro reaches steady state?

With a half-life of approximately 5 days, Mounjaro reaches steady state after about 4-5 weeks of consistent weekly dosing. Steady state means drug levels stabilize with consistent peaks and troughs.

Stability Window Details

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Average stable amount: - mg

Stable window days

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Mounjaro Calculator: Track Dose Levels & Reach Steady State

// HOW IT WORKS

How the Mounjaro Calculator Works

This free Mounjaro calculator uses pharmacokinetic modeling to track your tirzepatide levels over time. Enter your dose and schedule to see how the drug builds up in your system.

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Mounjaro Half-Life Calculator

With a 5-day half-life, see how concentration peaks after each injection and decreases between doses.

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Steady State Prediction

Know when you'll reach steady state (typically 4 weeks on Mounjaro) where drug levels stabilize.

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Visualize Drug Levels

Interactive chart shows tirzepatide concentration from 2.5mg through your target maintenance dose.

Mounjaro Dosing Guide

Mounjaro (tirzepatide) is an FDA-approved once-weekly injectable for type 2 diabetes. It's a dual GLP-1 and GIP receptor agonist, the same active ingredient as Zepbound, but approved for blood sugar control rather than weight management. Dosing starts at 2.5mg weekly and titrates up gradually. With a 5-day half-life, Mounjaro reaches steady state after about 4 weeks of consistent dosing at each tier.

Standard Mounjaro Dosage Chart

Tier	Weekly Dose	Duration	Pen Color
1	2.5 mg	4 weeks	Purple pen
2	5 mg	4 weeks	Brown pen
3	7.5 mg	4 weeks	Light green pen
4	10 mg	4 weeks	Dark green pen
5	12.5 mg	4 weeks	Gray pen
6	15 mg	Maintenance	Blue pen

Key Facts About Mounjaro

Active Ingredient: Tirzepatide
Half-life: Approximately 5 days
FDA Approval: Type 2 Diabetes (2022)
Maximum Dose: 15mg weekly
Administration: Once weekly subcutaneous injection
Mechanism: Dual GLP-1/GIP receptor agonist
Pen Options: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, 15mg (color-coded)

Mounjaro vs Zepbound

Mounjaro and Zepbound contain the same active ingredient (tirzepatide) but are approved for different indications. Mounjaro is approved for type 2 diabetes management, while Zepbound is approved for chronic weight management. The dosing schedule and available doses are identical between both medications.

Note: Individual dosing may vary. Always follow guidance from your healthcare provider.

// FAQ

Mounjaro Calculator FAQ

What is the half-life of Mounjaro?

Mounjaro (tirzepatide) has a half-life of approximately 5 days. This means after 5 days, about 50% of the drug remains in your system. The dual GLP-1/GIP mechanism provides blood sugar control throughout the week.

How long does Mounjaro stay in your system?

After stopping Mounjaro, it takes approximately 5 half-lives (about 25 days) for the drug to be essentially cleared from your system. Blood sugar effects may continue during this washout period.

When do I reach steady state on Mounjaro?

You reach steady state after approximately 4 weeks of consistent weekly dosing at the same dose level. At steady state, blood sugar control becomes more predictable as drug levels stabilize.

How many clicks is a Mounjaro pen?

Each Mounjaro pen contains one full dose and is designed for single use. Unlike some insulin pens, Mounjaro doesn't use "clicks" for dosing; you simply inject the entire contents. Each pen is pre-filled with the exact dose (2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, or 15mg).

How many mL is in a Mounjaro pen?

Mounjaro pens contain 0.5 mL of solution across all dose strengths. The concentration varies by dose: 2.5mg and 5mg pens have 5mg/0.5mL and 10mg/0.5mL respectively, while higher doses use more concentrated formulations up to 30mg/0.5mL for the 15mg pen.

Get started in seconds with our pre-built titration templates, or build your own custom schedule below.

Statistics

Peak Amount

Today's Amount

Average Stable Amount

Days until stable Click to learn how stability is calculated

Total Administered Complete Plot

Total Administered so far

Out of System (<0.02mg)

Weight Trend

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Drug Amount Plot

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Generate a schedule and click "Generate Plot" to visualize

What's a half-life?

The time your body needs to clear half a dose. After about five half-lives, a single dose is essentially gone. Tirzepatide has a half-life of roughly 5 days, so one dose takes about 25 days to clear; Semaglutide is closer to 7 days; Retatrutide is about 6 days.

Read the full half-life guide

What's steady state?

The point where what you take in each week equals what your body clears. Most weekly GLP-1s reach it after 4–5 weeks of consistent dosing — that's when blood levels stop climbing and the chart flattens out.

Read the full steady-state guide

Dose Schedule

Week	/Week	Date	Day	Time	Vial	IU	Dose (mg)	Weight (kg)	Journal	Actions

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