Does clozapine expire?
The printed date covers the sealed pack. Once clozapine is opened, mixed or diluted, its label sets a second and usually much shorter limit — quoted below, per product.
Shortest limit on any clozapine label: 100 days
“The suspension is stable for 100 days after initial bottle opening.”
That applies to the product it is printed on, not to every form of clozapine — check which one you have against the list below.
What the labels say
“The suspension is stable for 100 days after initial bottle opening.”
On the label for VERSACLOZ · DailyMed
How the label says to keep clozapine
Storage is the other half of the question: the stability behind any date assumes these conditions, and a medicine kept outside them ages faster than the calendar says.
- “16 HOW SUPPLIED/STORAGE AND HANDLING 16.”
- “and Handling Store at 20° to 25°C (68° to 77°F).”
- “Protect from moisture.”
- “Keep out of reach of children.”
- “and Handling Store clozapine tablets at room temperature between 20°C to 25°C (68°F to 77°F); excursion permitted between 15°C to 30°C (59°F to 86°F) [See USP Controlled Room Temperature].”
- “and Handling Store VERSACLOZ at room temperature between 20°C to 25°C (68°F to 77°F); excursion permitted between 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature].”
- “Do not refrigerate or freeze.”
- “Protect from light.”
Frequently asked questions
Does clozapine expire?
Two different clocks apply and only one of them is the printed date. The date on a sealed pack is the manufacturer's guarantee for the unopened product. Once it is opened, mixed or diluted, the label imposes its own limit — as tight as 100 days on some clozapine products, and that is the number quoted on this page.
Can I still use clozapine after the date on the box?
This page cannot tell you that, and nor can any page. The FDA's own shelf-life programme found 88% of tested lots stayed within specification at least a year past expiry — and concluded in the same breath that lot-to-lot variation means this can only be confirmed by testing each lot. What you can check at home is the in-use limit above and whether the product has been stored as the label requires. Ask a pharmacist about a specific pack; they will also dispose of what you no longer need.
Why do different clozapine products have different limits?
Because they are different formulations. A suspension that gets mixed with water, a pen that gets carried at room temperature, and a sealed tablet do not behave alike, so each manufacturer's label sets its own limit and each is shown here with the product it belongs to. We never merge them into one number for the molecule.
More on clozapine
Quoted from FDA labels for reference, not medical advice, and not a suggestion to use anything past its limit. If you are unsure whether a pack is still good, a pharmacist can tell you and can dispose of it safely.