K-Beauty: understand what "Glass Hair" is, a new trend in Korean beauty

Long shiny hair began to shine in several videos on TikTok and Instagram. It's not just shiny hair - it's "glass hair", so perfectly polished that its shine is like a mirror.

The new Korean beauty craze is an evolution of the "glass skin" trend, which considers radiance and radiance as indicators of overall health, says Rena Kim, global communications lead at CJ Olive Young, South Korea's largest beauty retailer.

"The Korean hair care market has traditionally placed a huge emphasis on consistent cleansing routines and maintaining straight, shiny, well-groomed hair," explains Kim.

Glass hair is an extension of this trend, the idea is to use a range of products and practices to help strands stay straight through conditioning, strengthening and protection, rather than straightening with intense heat or using products that weigh down the hair, she adds.

Achieving glass-like hair depends on cuticle alignment, adds Anabel Kingsley, consultant trichologist at hair and scalp care brand Philip Kingsley.

The hair cuticle is the protective outer layer of each hair strand, made up of overlapping cells, "like shingles on a roof," explains Kingsley. "It defends the inner part of the hair against damage, and what's more, a healthy, flat, closed cuticle reflects light better, making the hair shine more, so it's really important."

Damage caused by harsh chemicals in dyes and perms, or from excessive brushing and heat styling, can cause the hair cuticle to open, resulting in frizz or split ends.

Many glass-effect hair products promote shine by "sealing the hair cuticle," helping to strengthen and smooth it, says Kim. Pioneering brands like Mise-en-Scène and UNOVE - the latter launched earlier this year in US Sephora stores - use low pH formulas to help hair cuticles stay sealed and protein treatments to fill in gaps in damaged strands.

"Along with these treatments, styling devices and specialized hair brushes, designed to produce a sleek finish, are also gaining prominence in the market," adds the expert.

Style over substance?
The penchant for impeccable, refined aesthetics reflects South Korea's high - and often unrealistic - beauty standards. Men and women face enormous pressure to fit a certain standard of beauty, and the country has the highest rates of plastic surgery and the highest per capita spending on beauty products in the world.

Shiny hair can be the result of healthy strands, but unless you have naturally straight hair, "what most people have to do to achieve this effect ends up damaging their hair," says Kingsley.

For many types of curls, achieving the "smooth" finish needed for that shiny look often requires the use of intense heat tools and a lot of tension, such as brushing and pulling the strands tightly. Once damaged, the thread cannot be repaired, only protected, says Kingsley, who warns not to take this trend too seriously, as "everyone is different."

Gentle styling with lower heat and a good heat protectant, along with deep conditioning treatments and weekly bond repair treatments, are the best ways to keep your hair in good condition, "which has a huge impact on shine."

While it is possible to achieve glass hair through potentially harsh methods, Kim notes that consumers are generally moving away from "rigid, heavy-hold hairstyles" in favor of more natural styles, with an increase in interest in damage-preventing products such as UV and heat protectants, and nourishing leave-in and rinse-out hair masks, indicating a more holistic approach to hair care.

Scalp-first philosophy
Korean beauty's global expansion into the hair care sector comes at a time when hair loss problems are on the rise.

Hair loss is more common as people age, and by 2030 - when 1 in 6 people will be over 60 - the value of the global hair loss products market is expected to increase 82% compared to 2024, according to an analysis by Grand View Research.

In recent months, international tourists are already visiting South Korea for scalp massages and hair treatments, with a tourism experience platform reporting a 219% increase in scalp treatment bookings in the first 11 months of 2025 compared to the same period last year.

In December, South Korean President Lee Jae-myung put Korean hair care back in the spotlight by publicly advocating for hair loss treatments to be covered by health plans.

The scalp-first approach is deeply rooted in Korean self-care culture, says Kim, which is leading to the rise of "scalp skinification" - the application of common facial skin care approaches to the scalp.

"A popular saying in Korea, 'if the scalp gives one inch, the face gives three inches,' has driven consumer interest in scalp massages and myofascial release routines as part of broader self-care and beauty rituals," Kim added.

More technological approaches are also emerging, like Refilled's AI-powered scalp analysis device on display at CES 2026. Scalp scanners like Kérastase's K-Scan are nothing new.

But while these are typically used by professionals in salons, Refilled's device was designed for home use by consumers, explains Geunsik Jung, founder and CEO of Constant, Refilled's parent company, which raised $7.46 million in investment earlier this year.

The aforementioned device uses a tiny camera to take close-up photos of the user's scalp, which are then fed into an AI model trained with more than a million user data points. Users receive the results in an app, which provides "a very detailed and personalized diagnosis about your scalp and its health" and offers recommendations on diet, lifestyle and products to improve scalp health, Jung explains to CNN through an interpreter.

"The biggest problem with this whole process is that when you use a specific product, you don't know if it's working or not," says Jung. But using technology can provide users with a clear "before and after" so they can see if progress has been made.

Hair tissue treatments don't affect existing hair, but improve long-term hair growth and quality, says Kingsley: "Studies show that dandruff, for example, affects the health of the hair cuticle during hair growth. Therefore, keeping the scalp healthy and clean helps strengthen the hair cuticle."

People have always wanted shiny hair, says Kim, but she believes the emphasis on scalp health is what gives this trend staying power.

"Achieving glass-like hair goes beyond using hair oils or products that add shine. A healthy glow ultimately comes from consistent scalp and strand care."

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Source: CNN