New Hampshire middle and high schools must now provide free menstrual products to students under a bill signed Wednesday.

Describing access to period products as an issue of equality and dignity, Republican Gov. Chris Sununu added the Granite State to a movement aiming to help those who skip class because they can't afford tampons and sanitary napkins.

Those products must be available in female and gender-neutral restrooms at public middle and high schools, according to the bill. School districts will pay for the products.

“Being an adolescent middle or high-schooler is hard enough without the fear and embarrassment of lacking proper care products during the school-day because you cannot afford them,” bill co-sponsor Rep. Polly Campion said in a statement.

Free tampons for students:Boston latest to tackle 'period poverty' with $100K program

The state law comes one month after Boston approved stocking menstrual products at public schools teaching grades 6 through 12. Illinois and New York began requiring free period products in school restrooms for girls last year.

Supporters say such policies prevent students who can't afford period products from needing to stay at home or miss class to visit the school nurse for supplies.

Advocate groups including PERIOD have pushed for free menstrual products in all public school restrooms, gathering over 100,000 signatures for a petition to the U.S. Department Education. Supporters say the hygiene products are basic necessities, and ensuring easy access to them prevents disruptions to education.

'The period lady':This lawmaker pushed the Trump administration to put tampons in prisons

Other national efforts to fight "period poverty" include The Menstrual Equity for All Act introduced to Congress in March. The bill would make pads and tampons free for girls, homeless people, low-income women and prisoners. If passed, people could also pay for period products with health savings accounts.

Opponents say laws such as New Hampshire's are unconstitutional, unfunded mandates.

In a recent Saint Louis University study, two out of three women were found to have gone without menstrual products at least once during a year, while 21% went without the products on a monthly basis.

Tampons and other period products are also not exempt from sales tax in many U.S. states.

Menstruation lasts about two to seven days each month for those of reproductive age.

Contributing: Joey Garrison, USA TODAY