‘Mighty’ acne patch founder was an expat in South Korea when she discovered her $630 million cult skincare idea

Usually, an acne emergency isn’t anything to be thankful for, but Ju Rhyu credits a few bad breakouts for her almost overnight business success.

The founder of Hero Cosmetics, the skincare brand that vows to be your savior in the wake of acne problems, describes her career path as definitely not being “straight and linear.” Rhyu recently told Fortune it wasn’t until she was recruited for a job in Seoul, South Korea, that she stumbled on the big business idea that would launch a skincare line focused on a positive approach to troublesome acne.

The Mighty Patch allows wearers to embrace their zits and forgo the shame commonly associated with a bad breakout. The small patches—approximately 0.47 inches in diameter—have a transparent appearance, allowing for wearers to cover their blemishes at night or even in public. They’re a discrete alternative to other solutions for covering acne, such as makeup which can draw more attention to the face.

“I always joke that I worked at some of the world’s biggest brands—Kraft Foods, Mondelez, American Express, and Samsung Electronics—and then ended up starting an indie skincare brand,” she said.

At 35 years old, while working at a corporate marketing job for Fortune 500 giant Samsung, Rhyu was suffering from a bout of bad breakouts when she noticed something odd: Her coworkers were wearing hydrocolloid patches plain on their faces—in the office.

Puzzled, Rhyu asked why her colleagues were brazenly sporting Band-Aid-like squares and rectangles on their cheeks and chins, something she’d never seen in the United States. Their simple explanation? Taming a pimple.

“I went to a pharmacy, I tried one, and it changed my skincare routine because it works so much better than anything I had used before,” she recalled. “I put it on at night, and by morning, it got all that gunk out.”

That gunk—a combination of bacteria and dead white blood cells—is often what gives pimples their prominent appearance on the face. Being able to get rid of it overnight is a game changer for those who deal with acne, as it often leads to negative effects on self esteem.

The experience jumpstarted the young entrepreneur’s “education” in skincare. After trying “every single possibility out there” for acne relief–including dermatologists, toothpaste, and sticky pink creams–Rhyu set her sights on revolutionizing skincare, starting with the Band-Aid aisle.

Capitalizing on her corporate background, Rhyu began strategizing how to bring her idea to market alongside her two co-founders.

“One of the consumer behaviors I noticed was that the hydrocolloid-patch format was actually already around for quite a long time, but they were in the Band-Aid aisle,” she said. “There was nothing, at that time, in the beauty section.”