Dosing Guide

Last updated: May 2026

Tirzepatide Dosing Guide

This guide covers the dose escalation schedule for compounded tirzepatide, how to calculate draw volume from a vial, injection preparation, and common questions. It is a mathematical and procedural reference — not medical advice. Always follow your prescriber's specific instructions.

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What is compounded tirzepatide?

Tirzepatide is a dual GIP (glucose-dependent insulinotropic polypeptide) and GLP-1 receptor agonist. It activates both receptor pathways, promoting insulin secretion in response to meals, reducing appetite, and slowing gastric emptying. Compounded tirzepatide is produced by compounding pharmacies and supplied in multi-dose vials rather than pre-filled autoinjector pens.

Because doses range from 2.5 mg to 15 mg weekly — significantly higher in absolute mg than semaglutide — compounded tirzepatide is commonly available at higher concentrations (5 or 10 mg/mL) to keep draw volumes within a practical range for insulin syringes.

Standard dose escalation

Tirzepatide is introduced at a low starting dose and increased gradually. The schedule below reflects common escalation steps — your prescriber may modify the timing or increment size based on your individual response:

WeekDoseNotes
1–42.5 mg/weekStarting dose — tolerance development
5–85 mg/weekFirst increase if tolerated
9–127.5 mg/weekContinue if tolerating well
13–1610 mg/weekContinue escalation
17–2012.5 mg/weekNear-maximum dose
21+15 mg/weekMaximum maintenance dose

Common side effects during dose escalation include nausea, diarrhoea, decreased appetite, and fatigue. These are usually most pronounced in the first 2–4 weeks after each increase and often improve over time. Some protocols extend each dose level to 8 weeks rather than 4 if side effects are significant.

Calculating draw volume from a compounded vial

Divide your prescribed dose in mg by the vial concentration in mg/mL:

Formula

Draw (mL) = Dose (mg) ÷ Concentration (mg/mL)

Example — 7.5 mg dose from a 10 mg/mL vial

Concentration: 10 mg/mL

Dose: 7.5 mg

Draw = 7.5 ÷ 10 = 0.75 mL = 75 units (U-100 syringe)

On a U-100 insulin syringe, 1 unit = 0.01 mL. To convert mL to units, multiply by 100. The InjectBuddy calculator handles this automatically.

Calculate exact draw volume and syringe units for any tirzepatide dose and vial concentration.

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Common dose reference table

Dose2.5 mg/mL vial5 mg/mL vial10 mg/mL vial
2.5 mg1.00 mL (100 U)0.50 mL (50 U)0.25 mL (25 U)
5 mg2.00 mL (200 U)1.00 mL (100 U)0.50 mL (50 U)
7.5 mg3.00 mL (300 U)1.50 mL (150 U)0.75 mL (75 U)
10 mg4.00 mL (400 U)2.00 mL (200 U)1.00 mL (100 U)
12.5 mg5.00 mL (500 U)2.50 mL (250 U)1.25 mL (125 U)
15 mg6.00 mL (600 U)3.00 mL (300 U)1.50 mL (150 U)

At doses of 10–15 mg, a 2.5 mg/mL vial is impractical (4–6 mL draw). A 10 mg/mL vial keeps all doses within 0.25–1.50 mL, which fits a standard 1.5 mL or 2 mL syringe.

Injection preparation steps

  1. Wash hands thoroughly with soap and water.
  2. Gather supplies: vial, insulin syringe, alcohol swabs.
  3. Wipe the vial septum with an alcohol swab and allow 10–15 seconds to dry.
  4. Draw air into the syringe equal to your target volume.
  5. Insert needle through the septum, inject air, invert vial, and slowly withdraw your calculated volume.
  6. Flick the syringe to dislodge air bubbles and gently push them back into the vial.
  7. Clean the injection site (abdomen, thigh, or upper arm) with an alcohol swab and allow to dry.
  8. Pinch skin lightly, insert needle at 45–90°, and inject slowly.
  9. Withdraw, apply gentle pressure. Dispose of needle safely without recapping.

Storage

Store compounded tirzepatide vials refrigerated at 2–8°C (36–46°F). Do not freeze. Check with your pharmacy for specific room-temperature stability data for your product. Protect from light and check the expiry date on the label before each injection.

Frequently asked questions

What is the starting dose for compounded tirzepatide?
The standard starting dose for tirzepatide is 2.5 mg per week for the first 4 weeks. This is the lowest approved starting dose and is used to allow the body to adapt before escalation. After 4 weeks, the dose is typically increased in 2.5 mg increments every 4 weeks as tolerated, progressing through 5 mg, 7.5 mg, 10 mg, 12.5 mg, and up to a maximum of 15 mg weekly. The escalation schedule is determined by your prescriber based on your individual tolerability and therapeutic goals.
How does tirzepatide differ from semaglutide?
Tirzepatide is a dual GIP and GLP-1 receptor agonist, whereas semaglutide is a GLP-1 receptor agonist only. The dual agonism of tirzepatide is thought to contribute to its clinical profile. Both drugs are administered subcutaneously once weekly from compounded vials or brand-name pens. The dose ranges differ significantly: semaglutide tops out at 2.4 mg weekly, while tirzepatide reaches up to 15 mg weekly. Because tirzepatide doses are larger in absolute mg, it often comes in higher concentration vials (5 or 10 mg/mL) to keep draw volumes manageable.
How do I calculate tirzepatide draw volume from a compounded vial?
Divide your prescribed dose in mg by the vial concentration stated on the label in mg/mL. For example, a 7.5 mg dose from a 10 mg/mL vial = 7.5 ÷ 10 = 0.75 mL, which equals 75 units on a U-100 insulin syringe. The InjectBuddy tirzepatide calculator performs this conversion automatically for any dose and concentration combination. Always confirm the concentration on your specific pharmacy label before drawing, as compounded vial concentrations can vary by pharmacy.
What concentration vial is best for tirzepatide?
Higher concentration vials produce smaller draw volumes, which are generally easier to measure accurately on a standard insulin syringe. For higher tirzepatide doses (7.5–15 mg), a 10 mg/mL vial keeps the draw volume at 0.75–1.50 mL, which is within the range of standard 1 mL insulin syringes. A 2.5 mg/mL vial would require 3–6 mL for the same doses — well beyond standard syringe capacity. Most pharmacies supplying higher tirzepatide doses use 5 or 10 mg/mL concentrations. Confirm with your specific pharmacy what concentrations are available.
My draw volume is different from a friend who is on the same dose — why?
Draw volume depends entirely on vial concentration. If two people are on the same 7.5 mg/week dose but from different vials — one at 5 mg/mL and one at 10 mg/mL — they will draw 1.50 mL and 0.75 mL respectively for the same dose. Compounded vial concentrations vary between pharmacies and sometimes between batches. Always use the exact concentration printed on your current vial label when entering values into the calculator. Do not assume concentrations match a friend's vial or your previous order.

Sources

The dose escalation schedule in this guide reflects the protocol studied in the SURMOUNT-1 trial (tirzepatide 5, 10, and 15 mg/week for weight management in adults with obesity). The SURMOUNT-2 trial confirmed efficacy in adults with obesity and type 2 diabetes. Compounded tirzepatide is not covered by these trials — they used Eli Lilly's branded formulation. Always follow your prescriber's specific escalation schedule.

Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022;387:205–216. · Garvey WT, et al. Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes. Lancet. 2023;402:613–626.

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