Kwon Oh-sang, a dermatology professor at Seoul National University, who specializes in hair and scalp diseases such as alopecia, advised against washing one's hair daily for individuals in their 40s and up, citing its potential to accelerate hair loss.

“Generally the scalp tends to become dry after one's 40s, making it advisable to wash hair three to four times a week,” he said during an interview with a local media outlet on Tuesday.

Hair loss is a prevalent issue in Korea, with an estimated 10 million people affected, meaning 1 in 5 individuals, according to the National Health Insurance Service.

In 2021, the number of individuals seeking medical treatment for hair loss reached 240,000. Those in their 20s accounted for 20 percent of the total, those in their 30s for 22.6 percent, those in their 40s for 21.7 percent, and those in their 50s for 16.5 percent.

Additionally, Kwon also shared tips on the optimal water temperature for washing hair, noting that while cold water can stimulate the hair follicles, warm water is more effective in removing oily hair and sebum, so therefore is recommended.

However, Kwon dismissed the efficacy of shampoos and treatments for hair loss, stating that the helpful elements in their lather are usually washed away instantly.

“While these products may offer some benefits, they cannot match the effectiveness of dedicated hair loss medicine,” he said.

Addressing a common myth, Kwon explained that plucking one's grey hairs out is indeed detrimental to hair loss since the number of hairs that can emerge from a single hair follicle in a lifetime is limited.