Tirzepatide Dosage Chart and Titration Schedule

Tirzepatide is a dual GIP and GLP-1 receptor agonist studied for metabolic endpoints. In research and clinical settings it is typically introduced at a low dose and stepped up over time, an approach called titration. This page lays out a common week-by-week titration ladder and maps each step to the units you would draw on a U-100 insulin syringe, plus how concentration changes that draw.

This is reference math and general information only. It is not dosing advice, and it does not tell you what to take. Dose selection, timing, and whether titration is appropriate at all are decisions for a licensed clinician. To run any of the numbers below against your own vial, use the tirzepatide calculator.

The standard titration ladder

The dosing schedule most often referenced for tirzepatide moves through six dose levels, with roughly four weeks at each step before any increase is considered. The ladder exists so the body has time to adjust at each rung rather than jumping straight to a high dose.

• Weeks 1 to 4: 2.5 mg once weekly (starting step)
• Weeks 5 to 8: 5 mg once weekly
• Weeks 9 to 12: 7.5 mg once weekly
• Weeks 13 to 16: 10 mg once weekly
• Weeks 17 to 20: 12.5 mg once weekly
• Week 21 onward: 15 mg once weekly (highest referenced step)

Not every protocol climbs all the way to 15 mg, and a clinician may hold a dose longer, skip a planned increase, or step back down. The weeks above are a template, not a rule.

Each step in units at 10 mg/mL

A clean, common way to reconstitute is 10 mg/mL, for example a 30 mg vial mixed with 3 mL of bacteriostatic water (30 ÷ 3 = 10 mg/mL). On a U-100 syringe, 1 mL equals 100 units, so 10 mg/mL means every 0.1 mg works out to 1 unit. That makes the ladder easy to read.

• 2.5 mg = 0.25 mL = 25 units
• 5 mg = 0.5 mL = 50 units
• 7.5 mg = 0.75 mL = 75 units
• 10 mg = 1.0 mL = 100 units (a full U-100 syringe)
• 12.5 mg = 1.25 mL = 125 units (more than one syringe)
• 15 mg = 1.5 mL = 150 units (more than one syringe)

How concentration changes the draw

The same milligram dose pulls a different number of units depending on how concentrated the vial is. Concentration is just vial strength divided by the water you add. More water gives a lower concentration and a larger, easier-to-see draw. Less water gives a higher concentration and a smaller draw.

Take a single 10 mg dose across three mixes of a 30 mg vial:

• 30 mg in 6 mL = 5 mg/mL, so 10 mg = 2.0 mL = 200 units (two full syringes)
• 30 mg in 3 mL = 10 mg/mL, so 10 mg = 1.0 mL = 100 units
• 30 mg in 1.5 mL = 20 mg/mL, so 10 mg = 0.5 mL = 50 units

Same drug, same 10 mg, three different unit counts. This is why a units number is meaningless without the concentration attached. The general formula is: units = (dose in mg ÷ concentration in mg/mL) × 100.

Worked example

Say a vial is 60 mg and you add 3 mL of bacteriostatic water. Concentration is 60 ÷ 3 = 20 mg/mL. Now walk the early ladder steps:

1. 2.5 mg ÷ 20 mg/mL = 0.125 mL = 12.5 units
2. 5 mg ÷ 20 mg/mL = 0.25 mL = 25 units
3. 7.5 mg ÷ 20 mg/mL = 0.375 mL = 37.5 units
4. 10 mg ÷ 20 mg/mL = 0.5 mL = 50 units

At 20 mg/mL even the top 15 mg step is only 0.75 mL (75 units), so the whole ladder fits in one syringe. To check a vial size and water volume you actually have, plug them into the tirzepatide calculator or the broader peptide dosage calculator. For mixing volume choices, the reconstitution calculator finds a water amount that lands on round units.

Notes on reading the schedule

• Reconstituted vials are commonly treated as stable for a limited window (often cited around 28 days refrigerated). Concentration does not drift, but track your own dates.
• A half-life around 5 days is why once-weekly is the usual cadence in the literature. That cadence, not the math, is set with a clinician.
• If a draw lands on a half unit (for example 12.5 units), syringe markings may force rounding. A different water volume can produce cleaner numbers.
• Always confirm syringe type. These figures assume U-100. A U-40 or U-50 syringe reads differently.

For the full neutral framing on what these numbers are and are not, see the disclaimer. Titration decisions belong with a licensed clinician.