Does azithromycin expire?
The printed date covers the sealed pack. Once azithromycin is opened, mixed or diluted, its label sets a second and usually much shorter limit — quoted below, per product.
Shortest limit on any azithromycin label: 7 days
“Storage When diluted according to the instructions (1 mg/mL to 2 mg/mL), azithromycin for injection is stable for 24 hr at or below room temperature 30°C (86°F), or for 7 days if stored under refrigeration 5°C (41°F).”
That applies to the product it is printed on, not to every form of azithromycin — check which one you have against the list below.
What the labels say
“Storage When diluted according to the instructions (1 mg/mL to 2 mg/mL), azithromycin for injection is stable for 24 hr at or below room temperature 30°C (86°F), or for 7 days if stored under refrigeration 5°C (41°F).”
On the label for Azithromycin · DailyMed
“Storage When diluted according to the instructions (1 mg/mL to 2 mg/mL), ZITHROMAX for injection is stable for 24 hr at or below room temperature 30°C (86°F), or for 7 days if stored under refrigeration 5°C (41°F).”
On the label for Zithromax · DailyMed
“After mixing, store suspension at 5° to 30°C (41° to 86°F) and use within 10 days.”
On the label for azithromycin · DailyMed
“After mixing, store suspension at 5° to 25°C (41° to 77°F) and use within 10 days.”
On the label for Azithromycin · DailyMed
“After mixing, store suspension at 5°C to 30°C (41°F to 86°F) and use within 10 days.”
On the label for azithromycin dihydrate · DailyMed
“Discard after the 14 days.”
On the label for AZASITE · DailyMed
How the label says to keep azithromycin
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 Azithromycin Tablets USP, 500 mg are white to off-white, oval shaped, film-coated biconvex tablets, debossed with “67” on one side and “D” on other side.”
- “Store at 25°C (77°F); excursions permitted to 15° to 30°C (59° to 86°F) [See USP Controlled Room Temperature].”
- “After mixing, store suspension at 5° to 30°C (41° to 86°F) and use within 10 days.”
- “16 HOW SUPPLIED/STORAGE AND HANDLING AzaSite® is a sterile aqueous topical ophthalmic formulation of 1% azithromycin.”
- “and Handling Store unopened bottle under refrigeration at 2° to 8°C (36° to 46°F).”
- “Once the bottle is opened, store at 2° to 25°C (36° to 77°F) for up to 14 days.”
- “16 HOW SUPPLIED/STORAGE AND HANDLING Azithromycin Tablets USP, 500 mg are supplied as red, oval, film coated tablets containing azithromycin dihydrate equivalent to 500 mg of azithromycin.”
- “Store at 20° to 25°C (68° to 77°F); excursions permitted from 15° to 30°C (59° to 86°F) [see USP Controlled Room Temperature].”
Frequently asked questions
Does azithromycin 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 7 days on some azithromycin products, and that is the number quoted on this page.
Can I still use azithromycin 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 azithromycin 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 azithromycin
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.