Many arms were bitten in the name of science for the company Mimikai to soft-launch its mosquito and tick spray product line last year. The Portland, Oregon–based brand managed to do what no other company has done in 25 years: launch a new bug-repellent active ingredient as effective as DEET and approved by the Environmental Protection Agency (EPA).
The kicker? The active ingredient, undecanone, is naturally occurring in wild tomatoes and tropical fruits like bananas.
In 2001, based on anecdotal evidence that insects feeding on plants were avoiding an area where wild tomatoes grew, Dr. R. Michael Roe, an entomology professor at NC State University, tested his hypothesis and quickly realized he had discovered something remarkable. Dr. Roe told BeautyMatter that the impact on the mosquitoes was “immediate and dramatic.” He made a formal disclosure to NC State, and the university promptly filed for patents.
The brand raised $5.7 million through two funding rounds and a convertible note. Investors included: The Venture Collective, Newbound, Safer Made, Silas Capital, Human Ventures, and Chai Ventures.
After serial consumer product developer Stephanie Watson, Mimikai’s co-founder and President, sold her self-filtering water bottle startup Bobble to Seventh Generation in 2013, she went looking for her next big idea. Through her fascination with biomimicry, the process of emulating nature to solve human problems, the Australian native lost herself down a Google-research rabbit hole, which is how she stumbled upon Dr. Roe and his research.
“I cold-called him [Dr. Roe], and we had an awesome conversation about everything from bugs to life to science,” Watson told BeautyMatter. At this stage, Dr. Roe had completed initial trials to prove undecanone’s efficacy compared to DEET and picaridin, “but it was basically only in its active form, so there was no formulation around it. I'd never developed a formulation before, so Mike and I became the odd couple in terms of figuring out how to formulate this active ingredient.” Watson licensed the IP from NC State and immersed herself in the formulation process.
Watson’s first exposure to formulation was baptism by fire (or more aptly, baptism by mosquito swarms). “Every time we changed an ingredient, one of his students had to put their arm in a cage with 30 to 50 hungry mosquitoes to make sure the efficacy was on track,” Watson said. “Even my formulator said it was the hardest formulation he's ever worked on, because he's never had to test rigorously in the product development stage to make sure the efficacy was right.”
Once Watson and Dr. Roe knew they were done with the formulation, they took it to the EPA.
While most personal care products fall under the Food and Drug Administration (FDA) regulatory umbrella, bug repellants are categorized as pesticides and therefore regulated by the EPA. Watson thought that seeking a full EPA registration would take 18 months, but the process ended up taking five years. “And that was with regularly lobbying the EPA to prove our efficacy,” Watson said. “It's an incredibly tricky process, because you have to basically develop a data package, and that data package has three components to it: chemistry, toxicology, and efficacy. And that efficacy component means putting human subjects in the field at different geological locations around the US, under different biting pressures from insects, to test your efficacy.”
After more than 35 arm-in-cage studies, four EPA-approved protocol field studies (two tick and two mosquito), and review by the Human Studies Review Board—a federal advisory board to the EPA—undecanone was ready for prime time. Well, almost.
Watson felt she needed a like-minded partner to co-found Mimikai, so in late 2023, she enlisted industry veteran Michelle Arnau, who had spent 12 years at Method as co-founder and CEO. Arnau led the brand to partner with retailers Credo, REI, Erewhon and Grove Collaborative in 2025. “We launched in Credo in June of last year, and within two weeks, we sold out nationwide. As you can imagine, some of those Credo stores are in really buggy spots like New York and Chicago, and we became the #1 insect repellent overnight.”
Mimikai will have no issue with consumer demand, as the US heads into what experts warn could be one of the worst tick seasons on record: Weekly ER visits for tick bites are the highest for this time of year since 2017, according to the Centers for Disease Control and Prevention (CDC).
The brand just launched in all Nordstrom doors, and will launch on Goop on May 19. Arnau said the brand is now expanding into regional lifestyle, specialty, and outdoor stores. “You will see us in a lot of stores in New York and the Carolinas, some of the buggiest spots in the country, and a few more in the works that we can't talk about yet, but are coming soon.”