Tirzepatide Dosage Calculator
Calculate your exact tirzepatide dose in units and ml for compounded vials. Works for any concentration.
Common: 5mg, 10mg, 15mg, 30mg
What is Tirzepatide?
Tirzepatide is a dual GIP/GLP-1 receptor agonist, meaning it activates both the glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptors. This dual mechanism of action sets it apart from other incretin-based therapies like semaglutide, which only targets the GLP-1 receptor. It was originally developed for type 2 diabetes management and is now widely used for weight loss.
In the landmark SURMOUNT clinical trials, tirzepatide demonstrated remarkable weight loss efficacy. Participants on the highest dose (15 mg weekly) lost an average of 22.5% of their body weight over 72 weeks. This makes tirzepatide one of the most effective pharmaceutical options for weight management currently available, outperforming semaglutide in head-to-head comparisons.
Tirzepatide is available under the brand names Mounjaro (for type 2 diabetes) and Zepbound (for weight loss). Compounded tirzepatide is also available as a lyophilized powder that must be reconstituted with bacteriostatic water before injection. This calculator helps you determine the exact volume to draw for your prescribed dose based on your specific vial concentration.
How to Use This Calculator
- 1.Enter your vial size in milligrams. This is the total amount of tirzepatide in your vial (printed on the label). Common sizes include 5 mg, 10 mg, 15 mg, and 30 mg.
- 2.Enter how much bacteriostatic water you added (or plan to add) during reconstitution. Your pharmacy or provider will usually specify this amount.
- 3.Select or type your weekly dose. If you are just starting, use 2.5 mg and follow the titration schedule below.
- 4.Click "Calculate My Dose" and the calculator will show you the exact number of units to draw on your insulin syringe, the concentration, and the injection volume in ml.
Standard Titration Schedule
Tirzepatide is always started at a low dose and gradually increased every 4 weeks to minimize side effects.
Frequently Asked Questions
What is the starting dose for tirzepatide?
The standard starting dose is 2.5 mg once per week for the first 4 weeks. This allows your body to adjust to the medication and minimizes gastrointestinal side effects like nausea, diarrhea, and reduced appetite. Never start at a higher dose, even if you have experience with other GLP-1 medications.
How fast should I increase my tirzepatide dose?
The standard titration schedule increases the dose every 4 weeks: 2.5 mg, then 5 mg, then 7.5 mg, then 10 mg, then 12.5 mg, up to a maximum of 15 mg per week. Each increase should only happen if you tolerate the current dose well. Many people achieve excellent results at 5 mg or 7.5 mg without needing to go higher.
When should I inject tirzepatide, and does the day matter?
Tirzepatide is injected once weekly, on the same day each week. You can inject at any time of day, with or without food. Pick a consistent day (like Sunday or Monday) to make it easy to remember. If you need to change your injection day, make sure there are at least 3 days (72 hours) between doses.
How is tirzepatide different from semaglutide?
Tirzepatide is a dual GIP/GLP-1 receptor agonist, meaning it activates two incretin hormone receptors instead of just one. Semaglutide only activates the GLP-1 receptor. In head-to-head clinical trials (SURMOUNT and SURPASS), tirzepatide showed greater average weight loss (up to 22.5%) compared to semaglutide (around 15-17%). Tirzepatide also tends to have a slightly different side effect profile, though nausea remains common with both.
What are common side effects of tirzepatide?
The most common side effects are nausea, diarrhea, decreased appetite, vomiting, and constipation, especially during the first few weeks and after dose increases. These typically improve over time as your body adjusts. Eating smaller meals, staying hydrated, and avoiding high-fat foods can help manage symptoms. Contact your healthcare provider if side effects are severe or persistent.
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