As an offensive lineman for the NFL’s San Francisco 49ers, Joshua Garnett excels in one of the most macho cultures in the US, but he’s using his platform to tackle an issue long treated as too gross or too uncomfortable for men to talk about — periods and menstrual hygiene.

Garnett has teamed up with his sister Rachel’s organization Kitty Packs to help homeless women who experience “free bleeding,” which is what happens when a woman is unable to access expensive sanitary pads or tampons to manage her period.

Kitty Packs provides free menstrual hygiene kits to women in New York City’s homeless shelters who cannot afford clean hygiene products. More than 4,000 single adult women stayed in city shelters on Nov. 27 alone.

Take Action: #ItsBloodyTime to End the Taboo Around Menstruation

This football player is stepping up to help break the taboo behind people's periods. https://t.co/BQ4MLElkvT@49ers@IamJoshG#MyCauseMyCleats#PromotedPostpic.twitter.com/uJCssM2F8z

— Upworthy (@Upworthy) November 29, 2017

It’s not an issue men tend to discuss, but Garnett, who studied human biology at Stanford, wants to change that.

“Football players are thought to be about as manly as it gets,” he wrote in Upworthy. “So I’m here to tell you: It’s not un-manly to talk about menstruation.”

Read more: This Pad Ad Shows Period Blood as It Is. Here's Why That's Very Important

On average, women in the US spend about $120 per year on sanitary products and another $20 to manage cramps and other side effects. Homeless women often forego safe and sterile products and instead use home-made — and unhealthy — means for absorbing their menstrual blood, like tissues, paper towels, or dirty clothes.

Global Citizen campaigns on providing access to safe menstrual hygiene products to all women and combating period taboos worldwide. You can take action here.

In addition to donating money and period supplies, Garnett is encouraging men to check their own period biases and knee-jerk reactions to menstrual hygiene.

Read more: Indian Girl, 12, Kills Herself After Being Shamed for Having her Period

“Do away with the idea that you can’t pick up a pack of tampons at the store,” he said. “Don’t make a face when your friend mentions their cycle.”

“The more comfortable we get with menstruation, the better equipped we are to fight free bleeding."