(CNN)When Alexa Mohsenzadeh and Jenica Baron posted a video of bras on a fence to TikTok last July, they didn't expect to go viral.
The 19-year-olds from Barrington, Illinois, were promoting a collection drive for bras and hygiene products in the Chicago area, advertising free shipping labels for anyone who donated.
After the video garnered over 300,000 views and 90,000 likes, the duo decided to take their local efforts nationwide through their non-profit, Her Drive.
The organization, which Mohsenzadeh and Baron launched in June 2020, helps combat period poverty, a worldwide issue where women are unable to obtain menstrual products, by collecting items for women's shelters, indigenous reservations, Black-owned businesses, and refugee support programs.
"It's a really difficult issue for people that don't have access (to menstrual products)," Mohsenzadeh told CNN. "Because there was such a mobilized effort to collect PPE, we figured it was also a good time to launch something like this, because period poverty is very similar to hygiene poverty and the lack of masks, but it's more long term."
The group has held drives in over 40 states and Canada, collecting over 165,000 period products, 11,000 bras and 100,000 general hygiene items. They've also advised groups aiming to host drives in the United Kingdom.
They used their quarantine hobby to help others
When Baron took up sewing as a quarantine hobby last spring, she came to Mohsenzadeh with an idea: Why not sew bras and donate them?
The two have been friends since 6th grade, so Baron said it was a no-brainer that she wanted Mohsenzadeh to help.
"I trust her a lot with a lot of things in general," Baron told CNN. "I knew that going to her, planning would be able to start really quickly."
Realizing Mohsenzadeh didn't have similar sewing abilities, they chose to collect items advancing a common interest: fighting period poverty.
Roughly one in four women struggled to purchase menstruation products in the last year due to lack of income, according to the Alliance for Period Supplies, which organizes the collection and distribution of menstrual products in local communities.
Baron and Mohsenzadeh emphasized that despite the "her" in Her Drive, they assist people of all sexual and gender orientations.
"Half of our mission is alleviating period and hygiene poverty, and the other half is in doing that, supporting BIPOC communities or underrepresented communities that are in need," Mohsenzadeh said.
A TikTok video gave them national momentum
The non-profit held its first Chicago fundraiser in July. Baron and Mohsenzadeh collected bras, period products and hygiene items through porch pickups or mail deliveries.
They collected hundreds of bras and thousands of period products for local women's shelters, the Navajo Nation Covid-19 Emergency Relief Fund and the Oglala Sioux Tribe. They also donated $1,300 to the Brave Space Alliance Trans Relief Fund.
But they "didn't really have any intention of expanding Her Drive beyond our hometown because that's what we knew," Mohsenzadeh said.
As interest picked up, they decided to promote their efforts using TikTok -- a decision that paid off.
A day after Her Drive's TikTok video went viral, Baron and Mohsenzadeh woke up to hundreds of messages from others who wanted to help.
"We didn't plan for the social media success we've had," Baron said. "There's been a lot of rolling with the punches and getting really excited with how things have played out."
In a matter of months, Her Drive has expanded from two girls to hundreds of volunteers and donors internationally -- and they're still growing.
Here's what the organization hopes to do next
Since launching a "Host Your Own Drive" program in October, Mohsenzadeh and Baron have directly helped plan over 400 drives in the United States and Canada. And they've advised groups from the UK to Puerto Rico.
They release daily TikToks that discuss subjects ranging from how to pack period kits to lesser known products like menstrual cups, videos which have helped increase their following. The account has amassed more than 60,000 followers.
Besides spending 15 to 20 hours a week running the non-profit, Mohsenzadeh and Baron are both full-time college students.
Mohsenzadeh is a pre-law student at Emory University and Baron a public health major at Tulane University.
"I'm so invested and enjoy interacting with the volunteers so much that it just doesn't really feel like work," Mohsenzadeh said of their non-profit.
While they juggle the organization and their schoolwork, their families have helped pitch in from home -- both Mohsenzadeh and Baron have enlisted their younger brothers to unpack shipments and take inventory.
Their latest project is bringing products to Chicago Public Schools.
Nearly one in five girls in the US have missed school because of their period, according to a 2018 survey from feminine hygiene brand Always.
Not having bras also impacts students' abilities to be "deemed professional," Baron explained.
To address these issues, Her Drive partnered with Community in Schools Chicago to distribute "Care Kits" to students.
"We just wanted to be able to help girls our age, girls younger, to feel empowered through those issues so they can jump that hurdle," Baron said.
Going forward, the organization hopes to maintain "sustainability," particularly for indigenous communities that lack resources in rural areas, Mohsenzadeh said.
"It's been a really humbling experience, despite how successful we've been," Baron said. "We learned something new from every single group...the value of diversity, the value of really listening to people."
Their advice to others who aim to organize similar drives? Take advantage of what's in the area.
"The resources are there, and communities are already willing to help. It's just difficult tapping into that," Mohsenzadeh said. "We've learned to be very simple and straightforward with asking people to donate. Breaking that barrier to entry is really important, and social media does a pretty good job of that."