How long does Hydrogen Peroxide last?
How long does Hydrogen Peroxide last? pantry 3 months (opened). Plus spoilage signs, sources, and an unopened-vs-opened note.
Quick answer
Sealed / unopened: 3 years
Signs Hydrogen Peroxide has gone bad
- If it doesn't fizz on contact with skin or food (the test), it's broken down to plain water.
- No safety risk, just no efficacy.
Discard immediately if
- No bubbling reaction — it’s just water now, replace it
Why guidance varies
Active ingredients degrade at different rates depending on temperature, humidity, and light exposure; manufacturer dates assume controlled storage conditions.
Get a heads-up before it expires. Search the full database instead.
Frequently asked questions
How long does Hydrogen Peroxide last?
In the pantry: 3 months (opened). Sealed / unopened: 3 years. Test: pour onto a dark surface — should bubble vigorously. If it doesn't, it's broken down into water.
How can you tell if Hydrogen Peroxide has gone bad?
Signs that Hydrogen Peroxide has gone bad: If it doesn't fizz on contact with skin or food (the test), it's broken down to plain water; No safety risk, just no efficacy.
What does the date label on Hydrogen Peroxide mean?
Hydrogen Peroxide usually carries a "Use By" date. The last date the manufacturer recommends for peak quality — for most foods this is still quality-based, not a safety cutoff (infant formula is the one exception). See our date-labels guide for the full breakdown.
Sources for this answer
- A FDA — Don’t Be Tempted to Use Expired Medicines — Storage windows and refrigeration guidance for this category.
- A FDA — Are You Storing Food Safely? — Date-label interpretation and food-safety baseline.