Your period hasn’t arrived, and you want to know if that old test in your bathroom is worth using. Do pregnancy tests expire? If so, when?
Whether you’re TTC or trying not to, having some home pregnancy tests stashed away for when you need them can be a good idea.
But do pregnancy tests expire? Or do they continue to give accurate results indefinitely?
The short answer is that pregnancy tests don’t last forever.
Here’s how to use them to get the info you need so you can figure out your next steps.
In this article: 📝
- How do pregnancy tests work?
- Do expired pregnancy tests still work?
- Will an expired pregnancy test give a false negative?
- Can an old pregnancy test turn positive?
- Best pregnancy test practice
- Do expired pregnancy tests work? The bottom line
How do pregnancy tests work?
At-home pregnancy tests work by detecting hCG (aka “human chorionic gonadotropin,” aka “the pregnancy hormone”).
This hormone is released once an embryo implants in your uterus.
If there are sufficient levels in your system, you’ll get a positive result on your pregnancy test.
Pregnancy tests contain hCG antibodies, which react with the hCG in a pregnant person’s urine.
This reaction produces an enzyme that triggers a positive result in the form of a colored line, “YES,” or plus sign.
Chemistry in your very own bathroom!
But after a certain amount of time, those antibodies won’t be active anymore, so that reaction can no longer take place.
And that’s why pregnancy tests have an expiration date.
Do expired pregnancy tests still work?
Maybe. But they’re not reliable.
And that goes for both digital and non-digital options.
The test’s expiration date is usually stamped on the box and often on the individual wrapping of each test.
How accurate are expired pregnancy tests?
The more sensitive tests (i.e. those that can detect smaller amounts of hCG) may last a little longer than others.
But to be 100% sure, it’s best to stick within the expiration date.
And that’s usually one to three years from when the test was manufactured.
Will an expired pregnancy test give a false negative?
There is a chance of getting a false negative with an expired pregnancy test, yes.
There’s no way to know for sure if the hCG antibodies inside are still responsive.
And if they’re not, you’ll get a negative result — even if there is hCG in your urine.
So again, sticking with sticks still within their expiry date is best.
Can an old pregnancy test turn positive?
You’re more likely to get a false negative than a false positive on an old test.
And that’s because the older they get, the less likely they are to pick up hCG in your system.
But there is a chance that an older test could trick you into seeing a line that shouldn’t be there.
Manufacturer’s instructions always say you should read a result within a certain time frame to avoid inaccuracies.
After that period, if you see a line that wasn’t there before, it could be what’s commonly called an evaporation line.
This is when the urine dries and leaves a faint colorless line behind.
Frustrating and confusing — so it’s best to do what you can to follow the instructions exactly.
If you’re hoping for a pregnancy, it can be so hard looking for that second line, month after month.
A negative result may tempt you to go back and pull the test out of the trash to check.
But it’s simply not worth it.
Rather wait a couple more days and retest if your period still hasn’t arrived.
Best pregnancy test practice
Here’s our guide to help you make sure you get as accurate a result as possible.
- Check the date when you buy it.
- Check the expiration date when you use it.
- Store it in a cool dry place. Moisture may also impact the accuracy of your result.
- Test only after your period is due. This is a tough one, we know. Many tests claim to be able to give you a positive result days before your period is due. But they are in fact their most accurate a day or so after your missed period.
- Use your first morning pee. That’s when the hCG concentration is highest.
- Don’t be tempted to look at it again after the allotted time frame. It could cause you unnecessary confusion and heartache.
If you get a negative result, wait four or five days and try again if your period still hasn’t come.
If you see a (colored) line within the time frame, no matter how faint, that’s a positive.
Make an appointment with a health care provider to confirm the pregnancy as soon as you can.
Do expired pregnancy tests work? The bottom line
Taking an expired pregnancy test may feel tempting.
But we reckon it’s better not to even chance it.
If you need to take a test and the ones you have are out of date, wait until you can get one you know you can trust.
And if you’re unsure about when to take a pregnancy test, read more here.
Whatever the result, the Peanut community is here if you need to talk, rage, celebrate, cry, unload, or debrief. ❤️