Editor’s note: K-Everything: A CNN original series hosted by Daniel Dae Kim explores the global influence of Korean culture. The series is currently available on CNN International, CNN All Access, and HBO Max.
TikTok and Instagram are filled with flashes of long, shiny hair. This is not just shiny hair, but “glass hair” with a perfectly polished mirror-like luster.
“The K-beauty boom is an evolution of the ‘glass skin’ trend, which sees radiance and brightness as symbols of overall health,” said Lena Kim, global communications leader at CJ Olive Young, South Korea’s largest beauty retailer.
“The Korean hair care market has traditionally focused on consistent cleansing routines and maintaining smooth, shiny, well-groomed hair,” says Kim.
Glass Hair is an extension of that, with a variety of products and practices that help flatten hair through conditioning, strengthening and protection, rather than stretching it out with high heat or weighing it down with products, she added.
“Glass hair comes from the alignment of the cuticle,” says Annabel Kingsley, consultant trichologist for hair and scalp care brand Philip Kingsley.
The hair cuticle is the outer layer that protects each strand of hair and is made up of cells that overlap “like tiles on a roof,” explains Kingsley. “This is important because it not only protects the inside of your hair from damage, but also creates a healthy, flat, closed cuticle that reflects light better and makes it shine.”
Harsh chemicals in dyes and perms, as well as harsh brushing and heat styling, can damage your hair by opening up the cuticle, causing frizz and split ends.
Many glass hair products promote shine by “sealing the hair cuticle,” which helps strengthen and smooth hair, says Kim. Pioneering brands like Mise-en-Scène and Unov (the latter launched in Sephora stores in the US earlier this year) utilize low-pH formulas to flatten the hair cuticle and protein treatments to fill in the gaps in damaged hair.
“In addition to these treatments, styling devices and specialized hairbrushes designed to create a smooth finish are also gaining market attention,” Kim added.
The trend towards a perfect and sophisticated aesthetic reflects South Korea’s high and often unrealistic beauty standards. Both men and women face enormous pressure to look a certain way, and the country has the highest rate of cosmetic surgery and the highest per capita spending on beauty products in the world.
Shiny hair can be the result of healthy hair, but unless you have naturally straight hair, “what most people have to do to get it is end up damaging their hair,” says Kingsley.
For many hair types, achieving the “flat” finish required for that glassy look typically requires high-temperature styling and high tension, such as brushing or pulling the hair taut. Once hair is damaged, it can’t be repaired, it can only be protected, says Kingsley, warning not to take this trend too seriously as “everyone’s hair is different”.
Gentle styling with low heat and a good protectant, deep conditioning treatments and weekly bond repair treatments are the best ways to maintain good hair condition and “make a huge impact on shine,” says Kingsley.
While glass hair can be achieved through potentially damaging methods, Kim points out that consumers are generally moving away from “hard, structured styles” toward more natural styling, with increased interest in damage prevention products such as UV and heat protectants, and nourishing wash-in and leave-in hair masks, indicating a more holistic approach to hair care.
“There is a growing focus on scalp care as the foundation of healthy hair, and consumers are increasingly viewing scalp care, hair conditioning, and styling as part of a complete routine,” says Kim.
K-beauty’s global foray into hair care comes at a time when hair loss is a growing problem.
According to analysis by Grand View Research, by 2030, when hair loss becomes more common as we age and one in six people will be over 60, the value of the global hair loss market is expected to increase by 82% from 2024.
Overseas travelers are already flocking to South Korea for scalp massages and head spas, with one tourism experience platform reporting a 219% increase in scalp care bookings in the first 11 months of 2025 compared to the same period last year. In December, South Korean President Lee Jae-myung publicly called for hair loss treatment to be covered by health insurance, drawing attention once again to hair care in South Korea.
According to Kim, the scalp-first approach is deeply rooted in South Korean self-care culture, leading to the rise of “scalp-skinning,” which involves applying common approaches to facial skin care to the scalp.
“There is a popular saying in South Korea that says, ‘When your scalp drops 1 centimeter, your face drops 3 centimeters,’ and there is increasing consumer interest in scalp massage and myofascial release practices as part of a broader self-care and beauty routine,” says Kim.
More high-tech approaches are also emerging, like Refilled’s AI-powered scalp analysis device that will be showcased at CES 2026.
Scalp scanners like Kerastase’s K-Scan are nothing new. But while these are typically used by salon professionals, Refilled’s devices are designed for consumers to use at home, says Geunsik Jung, founder and CEO of Constant, Refilled’s parent company, which raised $7.46 million in funding earlier this year.
The device uses a small camera to take close-up photos of the user’s scalp, which are then input into an AI model trained on more than 1 million user data points. Users receive their results in the app, which provides a “very detailed and personalized diagnosis of their scalp and health,” and provides dietary, lifestyle and product recommendations to improve scalp health, Jung told CNN through an interpreter.
“The biggest problem with this whole process is that when you’re using a particular product, you don’t know if it’s working or not,” Jung says. However, the scanner gives users a clear “before and after” view so they can see if there is any progress.
Scalp treatments will not affect your existing hair, but will improve hair growth and quality in the long run. “Studies have shown that things like dandruff can affect the health of the cuticle that grows from your scalp, so by keeping your scalp healthy and clean, you’re helping your hair cuticle.”
Kim says people have always strived for shiny hair, and she believes focusing on scalp health will sustain this trend.
“Achieving ‘glass hair’ requires more than just using hair oils and glossy coating products. A healthy-looking glow ultimately comes from consistent scalp and hair care,” says Kim.
