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Tirzepatide units to mg

You are trying to work out how much to draw or when to step up.

Reference and calculator, not medical advice. Dosing figures below are transcribed from FDA-approved prescribing information and link back to it. Last reviewed August 2026.

Going backwards — from a mark on the syringe to a dose in milligrams — is the direction people need when someone has told them a units figure without saying what it means. It is the same arithmetic reversed: mg = (units ÷ 100) × concentration.

20 units = how many mg?

Reverse conversion: mg = (units ÷ 100) × concentration. U-100 syringe assumed.

If your vial is20 units equalsVolumeClosest labelled step
5 mg/mL1.00 mg0.20 mL2.5 mg
10 mg/mL2.00 mg0.20 mL2.5 mg
20 mg/mL4.00 mg0.20 mL5 mg

Notice how far apart these rows are. 20 units is not a dose until you know the concentration — quoting units without it is meaningless and is how dosing errors happen.

That table is the reason a units figure alone is not a dose. Twenty units is one mark on the syringe and three different quantities of drug depending on the vial it came from. Anyone quoting units without a concentration is describing their own vial, not yours.

mg → syringe units converter

U-100 syringe. Formula: (dose ÷ concentration) × 100.

12.5units on a U-100 syringe
= 0.125 mL  ·  2.5 mg at 20 mg/mL

Check the concentration printed on the vial you are actually holding. The same dose in milligrams is a completely different mark on the syringe at a different concentration. If the number here does not match what your prescriber told you, trust your prescriber.

Zepbound titration schedule

Tirzepatide · once weekly · subcutaneous injection · as published in the prescribing information

StepDoseNotes
Weeks 1–42.5 mgStarting dose — not intended for weight loss effect
Weeks 5–85 mg—
Weeks 9–127.5 mg—
Weeks 13–1610 mg—
Weeks 17–2012.5 mg—
Week 21+15 mgMaximum dose

This is the labelled default. Holding at a step longer than shown is common practice and is a decision for your prescriber. Transcribed from the Zepbound prescribing information (label revised 6 May 2026); checked against that label on 7 August 2026.

Common questions

How do I find my concentration?
Printed on the vial label, as mg/mL or as a total quantity in a total volume. If it shows the second form, divide the milligrams by the millilitres.
My converted dose is not on the labelled schedule.
Worth raising with your prescriber. Doses between labelled steps are prescribed in practice, but a figure that does not match what you were told to take is worth confirming before injecting.

Common questions

What is the starting dose of Zepbound?
The prescribing information lists 2.5 mg once weekly as the starting dose, held for the first four weeks before any increase.
What is the maximum labelled dose of Zepbound?
15 mg once weekly, reached through the stepped schedule shown above.
How many units is 5 mg at 20 mg/mL?
25.0 units on a U-100 syringe. The arithmetic is (dose ÷ concentration) × 100, and it only holds if the concentration on your vial matches.

Sources and last review

Every dosing figure on this page is transcribed from an FDA-approved label and links back to it. Conversions are arithmetic you can repeat by hand. Nothing here is reviewed by a clinician, and this site does not employ one — which is exactly why what I do publish stays traceable to its source.

Transcribed from the labels above and checked by me — Gavin, who builds this site, takes a GLP-1, and is not a clinician. Last reviewed August 2026. Found an error? [email protected] — I treat corrections as bugs. How this site is built and funded.

Also searched as: tirzepatide mg to units

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