Tirzepatide Calculator

Tirzepatide dosage calculator

The Tirzepatide dosage calculator above converts a target dose into exact syringe units based on your vial size and how much bacteriostatic water you used to reconstitute it. Tirzepatide is commonly sold in 5 mg, 10 mg, 15 mg, 30 mg, 60 mg vials. The calculator supports both U-100 and U-40 insulin syringes and flags draws that are too large for the syringe barrel or too small to measure accurately. A dual GLP-1 and GIP receptor agonist that simultaneously activates two incretin receptors through a single engineered peptide. Enter your target dose in the calculator above to see the exact number of units to draw.

Tirzepatide dosage chart

Tirzepatide and GLP-1 peptides

Tirzepatide is a GLP-1 / GIP dual agonist. A dual GLP-1 and GIP receptor agonist that simultaneously activates two incretin receptors through a single engineered peptide. The same molecule is the active ingredient in Mounjaro and Zepbound, which are FDA-approved prescription medications manufactured by their respective companies. Research-use Tirzepatide is regulated differently and is not approved for human consumption. Other peptides in the GLP-1 class include Semaglutide , and Retatrutide .

Tirzepatide is a synthetic peptide that has been engineered to activate two incretin receptors simultaneously: the glucose-dependent insulinotropic polypeptide (GIP) receptor and the GLP-1 receptor. Published research has studied its dual-agonist pharmacology in the context of glucose regulation, gastric emptying, and energy balance. Like semaglutide, the molecule incorporates a fatty acid linker that extends its circulating half-life through albumin binding. Tirzepatide has been the subject of Phase III clinical programs reported in journals including the New England Journal of Medicine, and has been approved by regulatory agencies under brand names including Mounjaro and Zepbound for use by prescription. Research-grade tirzepatide sold by chemical supply companies is labeled for laboratory use only and is not approved by the FDA for human consumption.

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How to reconstitute Tirzepatide

Research chemical vendors commonly offer tirzepatide in lyophilized vials ranging from 5 mg to 60 mg. Larger vials are typically reconstituted with proportionally more bacteriostatic water to keep draw volumes manageable.

Reconstituting Tirzepatide is the same unit-conversion process used for any lyophilized peptide:

1. Draw your chosen volume of bacteriostatic water into a syringe.
2. Inject the bacteriostatic water slowly down the side of the Tirzepatide vial — do not shoot it directly onto the powder.
3. Swirl gently until the powder fully dissolves. Do not shake.
4. Store the reconstituted vial refrigerated.
5. To dose, calculate your draw volume: divide your target dose by the concentration (vial mg ÷ water mL = mg/mL). The calculator above does this automatically.

For Tirzepatide specifically, 5 mg, 10 mg, 15 mg, 30 mg, 60 mg vials are common. A typical reconstitution adds 2 mL of bacteriostatic water, producing a concentration of 7.5 mg/mL for the 15 mg vial size.

Tirzepatide half-life and storage

Published pharmacokinetic studies report a terminal half-life of approximately 5 days, attributed to the molecule’s albumin-binding design.

Lyophilized tirzepatide is typically stored refrigerated at 2–8 °C, protected from light. Once reconstituted, published and manufacturer sources commonly report stability of several weeks under refrigeration, depending on buffer and handling.

Common Tirzepatide dosing mistakes

Most Tirzepatide draw errors are unit errors, not arithmetic errors: confusing mg with mcg (1 mg = 1,000 mcg), or reading a U-40 syringe with U-100 math — the same printed mark holds 2.5× the volume. Two more worth avoiding: leaving the vial unlabeled, so the concentration and reconstitution date are lost, and under-diluting to the point where the draw is under about one unit and can no longer be read accurately.

Each of these is covered in full in the guides: reconstitution math from first principles, U-100 vs U-40 syringes, storage and shelf life, and how to reconstitute peptides.