A vial of tirzepatide lasts four weeks at most. The brand label caps it at 4 weekly doses[1]. FDA caps a compounded vial at 28 days after first use[3].
Tirzepatide is dosed once a week. So four weeks is four doses. Whatever the vial holds beyond that is discarded.
The brand vials
Zepbound comes in single-dose and multi-dose vials[1]. A single-dose vial is one week[1]. A multi-dose vial holds 4 weekly doses[1].
The label says to throw away an opened multi-dose vial after 30 days, or after 4 weekly doses[1]. That applies even if medicine is left[1].
LillyDirect defines a vial month as 28 days and 4 single-dose vials[2]. Needles and syringes are bought separately[2]. The full price ladder is in Zepbound price.
Compounded vials
FDA notes that compounded GLP-1 drugs may be dispensed in vials holding several doses[3]. It recommends using such a vial within 28 days of first use[3]. The reason is a higher contamination risk after that[3].
FDA adds: discard it at 28 days even if the pharmacy says it lasts longer[3]. It also says to use a new, sterile needle and syringe for each dose[3].
How many milligrams a month uses
Multiply the weekly dose by four. That is what a 28-day vial must hold. Anything above it is waste.
| Weekly dose | Used in 4 doses | Zepbound month | Per milligram |
|---|---|---|---|
| 2.5 mg | 10 mg | $299 | $29.90 |
| 5 mg | 20 mg | $399 | $19.95 |
| 7.5 mg | 30 mg | $449 | $14.97 |
| 10 mg | 40 mg | $449 | $11.23 |
| 12.5 mg | 50 mg | $449 | $8.98 |
| 15 mg | 60 mg | $449 | $7.48 |
Per milligram, the starting dose costs $29.90. At 15 mg it is $7.48. The month’s price rises slower than the milligrams.
The label’s doses step up by 2.5 mg after at least 4 weeks[1]. So most months use a different amount. Price the maintenance dose.
Against the compounded month
$249
Typical compounded month (361 sellers)
$83
Lowest published compounded month
$634
Highest published compounded month
Those are monthly figures, as sellers bill them. Ask each one what dose the price covers. Seller prices were read through September 2026.
Each seller’s figure is on the tirzepatide price board. What pharmacies may still compound is in is compounded tirzepatide legal. Storing a vial between doses is covered in how to store peptides.