The shelf life of tampons is about five years — provided they're left in the package undisturbed and not exposed to excessive moisture. Tampons are sanitary products, but they're not packaged and sealed as sterile products. ... If you know a tampon is expired, don't use it, even if it looks fresh.

How do you know if a tampon is expired?

You may not know that your tampons have expired just from looking at them. Instead, look for the expiration date on the side of your TAMPAX box. There will be two dates printed. One is the date of production, and the other is the month and year your tampons are due to expire.

Can I use a 10 year old tampon?

There is no medical reason your tween can't use tampons from the onset of their period. Tampons are completely safe to use, and kids as young as 10 years old can use them if they are comfortable with using them.