Does famotidine expire?
The printed date covers the sealed pack. Once famotidine is opened, mixed or diluted, its label sets a second and usually much shorter limit — quoted below, per product.
Shortest limit on any famotidine label: 48 hours
“Therefore, it is recommended that if not used immediately after preparation, diluted solutions of Famotidine Injection should be refrigerated and used within 48 hours (see DOSAGE AND ADMINISTRATION ).”
That applies to the product it is printed on, not to every form of famotidine — check which one you have against the list below.
What the labels say
“Therefore, it is recommended that if not used immediately after preparation, diluted solutions of Famotidine Injection should be refrigerated and used within 48 hours (see DOSAGE AND ADMINISTRATION ).”
On the label for Famotidine · DailyMed
“Although diluted Famotidine Injection has been shown to be physically and chemically stable for 7 days at room temperature, there are no data on the maintenance of sterility after dilution.”
On the label for Famotidine · DailyMed
“Discard unused constituted suspension after 30 days.”
On the label for Famotidine · DailyMed
How the label says to keep famotidine
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 Famotidine Tablets USP, 20 mg, are light yellow, round, biconvex, film-coated tablets debossed with “T” on one side and “11” on the other side.”
- “Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].”
- “store at 20° to 25°C (68° to 77°F) protect from moisture Directions adults and children 12 years and over: to relieve symptoms, swallow 1 tablet with a glass of water.”
- “Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].”
- “Avoid storage of famotidine tablets at temperatures above 40°C (104°F).”
- “Store at 20°C to 25°C (68°F to 77°F) [See USP Controlled Room Temperature].”
- “Protect from freezing.”
- “of Constituted Suspension Shake the bottle of constituted famotidine for oral suspension vigorously for 5 to 10 seconds prior to each use.”
Frequently asked questions
Does famotidine 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 48 hours on some famotidine products, and that is the number quoted on this page.
Can I still use famotidine 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 famotidine 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 famotidine
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.