How long does a vial last after opening? First puncture, mixing and expiry

Three separate clocks decide when an opened or mixed vial is discarded: first puncture, mixing and the printed expiry. The CDC multiple-dose rule, single-dose rules, and real labels such as EGRIFTA WR (7 days after mixing) and EGRIFTA SV (use immediately), each with its source.

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The three clocks

First puncture, mixing and the printed expiry, and how each is set.

First puncture

Starts the first time a needle goes through the stopper. For a multiple-dose vial, CDC guidance is to date it and discard it within 28 days unless the manufacturer gives a different date. A single-dose vial has no in-use period at all: it is used once and leftovers are discarded.

Mixing (reconstitution)

Starts when powder is mixed with its liquid. The product's own label sets how long the mixed medicine may be kept and how. It can be far shorter than 28 days, and the liquid bottle's own clock does not extend it.

Printed expiry

The date printed on the vial or carton. Nothing extends it: an expired label wins over any in-use period that has not run out yet.

What real labels say

Labelled in-use periods quoted from real products, each with its source.

General rule (any labelled multiple-dose vial)

Multiple-dose vial: date it when first opened or punctured and discard within 28 days unless the manufacturer specifies a different date. Single-dose vial: for one patient and one procedure; leftovers are not kept for later, not even for the same patient. Discard any vial sooner if its sterility is in question. Primary source

EGRIFTA WR (tesamorelin), mixed with bacteriostatic water

Mixed medicine: use within 7 days of mixing, stored at room temperature (20–25 °C), not refrigerated and not frozen. The bacteriostatic water bottle has its own, separate 28-day period after first opening. The kit is for one patient only, which is not the same as single-dose. Primary source

EGRIFTA SV (tesamorelin), mixed with sterile water

Use immediately after mixing. Discard any unused medicine and the supplied sterile water; neither is kept for a later injection. Do not refrigerate or freeze. Primary source

Bacteriostatic Water for Injection (Hospira)

The bottle's own in-use clock is about the water, not about any medicine mixed with it. Mixing a drug with it does not give the mixed drug the water's period; the drug's label decides. Primary source

Sterile Water for Injection (Hikma)

Single-dose: enter once and discard what is left. It has no multiple-dose in-use period. Primary source

Testosterone cypionate (Hospira)

Nothing is mixed. The 1 mL vial is single-dose (discard what is left); the 10 mL vial is multiple-dose and follows its label and the general multiple-dose rule. The size on your carton decides which applies. Primary source

Testosterone enanthate (Eugia)

Multiple-dose. The label read on the checked date gives no separate in-use date that overrides the general rule, so the general multiple-dose rule and the printed expiry apply. Primary source

XYOSTED (testosterone enanthate) autoinjector

Single use: one injection, then the whole device is discarded. No vial clock applies. Primary source

AVEED (testosterone undecanoate)

Discard any unused portion. Nothing is kept for later. Primary source

Products without a manufacturer label

Why no period can be borrowed for a product with no verified label.

Compounded products

A compounding pharmacy assigns a beyond-use date (BUD) to what it prepares. Follow the BUD and storage on the pharmacy label; ask the pharmacy if it is missing.

Research-only products

With no approved label, no in-use period has been established. The 28-day multiple-dose rule is for labelled multiple-dose vials and cannot be borrowed for an unverified product.

Label-based discard reminder

An optional date reminder from a period your own label states.

Common questions

Short answers to the questions people ask most.

Educational use only, never medical advice. No doses.