A new school year is underway. Kids are getting new notebooks and backpacks — and also sharing what no parent wants their child to come home with: head lice.
Joanna Shu, founder and CEO of Cartwheel, created Nit Happens, a natural, pesticide-free lice treatment designed to give families an alternative.
Shu graduated from Boston University in 2004 and earned an MBA in finance from BU’s Questrom School of Business in 2008. She later founded her own natural skin care brand, Refresh Skin Therapy. She said her products have been sold at Costco, Sam’s Club, Walmart and Rite Aid.
Shu has lived with her family in Marblehead for seven years. She is the mother of three children — in high school, middle school and kindergarten — and her husband works in health data and artificial intelligence.
Shu said lice outbreaks are no stranger to her family.
“All three of them had lice at some point, and every option was a bad option: pesticide, harsh chemicals or low efficiency,” Shu said.
In March 2026, Shu launched Nit Happens, with products sold in 6,000 Walgreens stores nationwide. Based on a clinical study, Shu said the product is 95.8% effective.
For two years, Shu worked with a retired chemist who tested formulas and ran clinical studies until the product was approved as safe for skin.
No matter who you are, Shu said, lice outbreaks can happen in any family. She said families should be prepared, especially around the start of the school year and after children may have picked up lice at camp or on vacation.
“Taking stigma away matters as much as killing the bugs,” Shu said.
Cartwheel has also introduced Nit Happens School Day Spray, a detangler made with ingredients that repel lice based on lab tests, Shu said.
The company’s connection to schools extends beyond lice treatment. Shu said she recently launched the Mayflower Award for Excellence in School Nursing, which recognizes Massachusetts school nurses for their work caring for children.
“School nurses do such an amazing job,” Shu said. “We’re so lucky in Marblehead to have the best nurses who take incredible care of our kids.”
Nit Happens has also drawn praise from Cathy Henry, vice president of sales for Cartwheel, who lives in Dallas.
Henry said she met Shu through her work as a sales and marketing mentor at Health Wildcatters, a Dallas-based incubator, in 2023. The two partnered and became close friends. Henry said Nit Happens stands out because it gives parents an alternative treatment option.
“Rather than relying on traditional chemical pesticides, Nit Happens uses a mechanical method of action with natural ingredients.,” Henry said.
The road to getting her product onto store shelves was not easy, but once Nit Happens went on sale at Walgreens, Shu was thrilled to see it there, even telling other customers that it was her product.
Looking ahead, Shu wants to continue building Cartwheel as a first-aid brand for families.
“The goal is for Cartwheel to be the trusted, modern medicine cabinet,” she said.
