Aunt Flo is one helluva house guest. She can be painful, messy, and just keeps coming back each month. And, oh yeah, expensive! As anyone who menstruates knows, dealing with a period is a monthly necessity—and a costly one at that. Women spend upwards of $70 a year on sanitary products like tampons and pads.

What’s worse, across the U.S., a whopping forty states increase the financial burden of menstruation by charging sales tax on these essential items.

Not taxed: a bag of chips.

Taxed: a box of tampons.

WHAT?!

Check out the above map to see if your state is one of the forty that taxes your purchase of tampons, pads, and menstrual cups.

For anyone who has a period, these items are a necessity—not an option, not a luxury item—and should be treated as such. Eliminating the Tampon Tax is simply the FAIR and EQUAL thing to do.

Change is possible! This summer, Canada made history when its Parliament voted unanimously to eliminate a national tax on menstrual products. Across the pond and down under, women in the U.K. and Australia are insisting their governments do the same. A global movement is underway!

Sign this petition, share it with your friends—and let the forty state legislatures that profit from your period know that you won’t stand for it. Join Cosmopolitan in the national movement to Axe the Tampon Tax! #TamponsForAll