Kao's "MEMEME Smooth Boost" Fully Explained: Formula Framework, Low-Irritation Design, and Hands-On Testing

The new blue Smooth type keeps the strong framework of the red line. So what formula changes have been made, and what hair and skin types is it designed for? From a cosmetic chemistry perspective, this article analyzes the ingredients of the shampoo, the in-shower treatment, and the all-new leave-in treatment, "Shower Veil Treatment," in detail. It also explains the results of testing done with human hair extensions.

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In recent years, Kao's hair care development has reached a major turning point. The company's drugstore hair care used to be dominated by inexpensive shampoos built on strong sulfate-based cleansers, and salon professionals and ingredient-conscious consumers tended to view it in uniform terms. Kao is one of Japan's leading major corporations, with nearly 100 years of hair care research and many proprietary ingredients to its name. Even so, there was a sense that its research assets were not being fully passed on to its mass-market consumer products.

What changed that trend was the "Essential Barrier Shampoo (the prototype of what is now Essential Premium)," released between 2022 and 2023. This product established the basic formula framework and marked Kao's move away from the sub-¥1,000 price range and its full-scale entry into the "high-premium" range of ¥1,500 to just under ¥2,000.

This transformation gave rise to brands such as "melt" and "THE ANSWER," and the third brand launched was "MEMEME," aimed mainly at young people (around their 20s). While the existing red bottle (Moist Boost) focused on moisture and a soft, hydrated feel, the new blue bottle (Smooth Boost) is positioned as a series aiming for "silky, glossy hair" that bounces lightly all the way to the ends.

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Looking at the full ingredient list of "MEMEME Smooth Boost Shampoo," you can see that its composition is extremely close to that of the red Moist type.

The main ingredients are sodium methyl cocoyl taurate, a taurine-based anionic surfactant, and sodium lauroyl methylaminopropionate, an amino acid-based anionic surfactant. These are well-balanced cleansing agents that provide moderate cleansing power while keeping irritation low. They are combined with cocamide methyl MEA to boost foaming; the amphoteric surfactants sodium cocoamphoacetate and cocamidopropyl betaine, which reduce irritation and adjust lather quality; and laureth-11 carboxylic acid, an acidic soap-type (carboxylic acid-type) surfactant that is one of Kao's specialties.

This combination is the basic framework commonly seen across Kao's high-premium products, offering a balance suited to everyone that pairs sufficient cleansing power with mildness.

The differences from the red Moist Boost lie in adjustments to minor ingredients. First, sodium lauroyl hydrolyzed silk, a moisturizing amino acid-based cleanser, is listed slightly lower in the blue version, which appears to be a fine-tuning of the amount aimed at a fresher, cleaner finish. Glycerin, a humectant, has also moved further back in the list compared with the Moist type.

Among the botanical extracts, the royal jelly extract found in the red version has been dropped and replaced with eucalyptus leaf extract. Eucalyptus leaf extract is a plant-derived ingredient with a cooling feel, but judging from the amount used, it is presumed not to be enough to give the scalp a strong cooling sensation.

The following hair repair ingredients are shared between the two types:

• PPT-type repair ingredients: hydrolyzed keratin (wool), hydrolyzed silk, hydrolyzed conchiolin (a protein derived from mother-of-pearl)
• Hair lipid repair: lanolin fatty acids (a derivative of 18-MEA, the natural lipid on the hair surface, developed by Kao)
• Pseudo-ceramide: bis-methoxypropylamidoisodocosane (a Kao proprietary ingredient that supplements the hair's lipid structure)
• Heat protection ingredient: γ-docosalactone (an ingredient that bonds with hair under the heat of a hair dryer or flat iron to repair it)

Stearoxypropyl dimethylamine appears at the end of the ingredient list. This is a type of cationic surfactant (a tertiary amine salt). Compared with the "quaternary ammonium salts" generally considered problematic in drugstore shampoos, tertiary amine salts have extremely low skin irritancy, and since the amount used is tiny, the speaker assesses the risk of scalp irritation as practically negligible.

Overall, this is the freshest-feeling shampoo formula among Kao's high-premium lineup, specialized for a silky, smooth feel.

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The formula of "MEMEME Smooth Boost Hair Treatment" has a feature that is very rare for a drugstore treatment. It contains none of the irritating cationic surfactants ("quaternary ammonium salts" such as steartrimonium chloride and cetrimonium chloride) that are used at high levels in typical products.

As its softening base, it uses stearoxypropyl dimethylamine, a tertiary amine salt also used in hand creams and low-irritation products. Irritation when the treatment gets on the neck or back, areas prone to skin trouble, is greatly reduced, making it a design well suited even to sensitive skin.

Kao treatments usually include a high level of silicone oils such as dimethicone, at around second place among the base ingredients, to create a rich, coated feel. This product, however, is built on glycerin and stearyl alcohol, with dimethicone placed relatively far back in the list. This achieves a finish that isn't heavy and lets fingers glide through easily.

It also contains lactic acid, which has been drawing attention in recent years as an ingredient for correcting frizz and waves. Lactic acid penetrates the hair and relieves the stress that causes it to contract, giving the hair a silky, well-behaved feel.

Compared with the Moist type, the blue Smooth type lists the pseudo-ceramide (bis-methoxypropylamidoisodocosane) higher, while moisturizing ingredients such as hydrolyzed collagen are toned down. Ester oils such as PPG-3 caprylyl ether and isopropyl palmitate, along with polyglycerin-3, have also been added, showing an effort to create a light, silky texture without leaving a coated feeling.

Especially notable is the use of a "lamellar structure" in the treatment itself. Unlike ordinary oil-rich treatments, a formula with a lamellar structure tends to hold water readily. As a result, although it is a translucent gel, it achieves a texture that "blends in explosively fast," merging rapidly with the moisture in the hair the moment it is applied, and it rinses out quickly without leaving any slipperiness.

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The "Shower Veil Treatment," a leave-in treatment newly added to the blue series, is a mist-type out-of-bath product.

【Main framework of Shower Veil Treatment】
Water, ethanol, DPG, γ-docosalactone, lanolin fatty acids,
hydrolyzed keratin (wool), hydrolyzed silk, hydrolyzed conchiolin,
hydrolyzed collagen, lactic acid, PEG-12 dimethicone, etc.

Ethanol appears near the top of the ingredient list, but in a leave-in hair mist, ethanol has practical advantages. After it is sprayed onto the hair, the ethanol takes up water as it evaporates and helps that water evaporate, which can greatly shorten blow-drying time. Since it isn't rubbed directly into the scalp, there is also little concern about skin irritation.

The most noteworthy point is that, despite being a leave-in treatment, it is completely free of cationic surfactants (both quaternary ammonium salts and tertiary amine salts). For an out-of-bath product that easily comes into contact with skin, a design without cationic surfactants deserves high marks as a consideration for sensitive skin.

Hair oils based mainly on high-viscosity silicone oils or plant oils carry the risk of "buildup (film accumulation)," in which a coating accumulates on the hair surface and makes it feel stiff and rough. This product, by contrast, is a mist, so buildup from heavy oils is unlikely.

Because it contains a solid amount of the heat-activated repair ingredient γ-docosalactone, it can use the heat of a hair dryer or flat iron to repair lifted areas on the hair surface, creating a natural, silky feel while preventing friction damage.

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Testing of the actual feel and finish was carried out using 100% human hair extensions.

The shampoo is a clear-looking liquid. While Kao's "THE ANSWER" is designed to be extremely mild with somewhat gentle foaming, MEMEME Smooth Boost quickly whips up a very rich, springy, fluffy lather. You can wash without feeling friction on the hair, and it rinses out very well without leaving any slipperiness.

The fragrance is described as "Rosé Sparkling × Amber." While the red Moist type strongly pushed a sweet, fruity scent, the blue version has a fresh, clean scent profile without excessive lingering fragrance. Even compared with Kao's recent products (such as melt and THE ANSWER), its scent is described as understated and easy to live with.

The treatment isn't fully opaque white but has a somewhat translucent gel texture. When applied to a section of hair, it instantly spreads through all of it, merging with the water and turning into a silky, melting texture. True to the properties of the lamellar structure, it blends in extremely quickly.

It also mixes quickly with water when rinsing, so slipperiness never lingers and rinsing is done in a short time. It also suits people who want to cut down on rinsing time in the shower.

When "Shower Veil Treatment" was applied to the towel-dried hair section, the hair instantly took on a silky, smooth slip thanks to the action of ingredients such as the 18-MEA derivative (lanolin fatty acids), despite the product being free of cationic surfactants.

When blow-dried, the hair dried very quickly, aided by the evaporation-assisting effect of the ethanol. After drying, the hair had none of the heaviness or stickiness of layered-on oil, and it finished as light, airy, silky straight hair, with each strand separate as if holding air. Compared with the red series, the result was clearly silkier.

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The prices of MEMEME and Kao's other high-premium hair care brands are as follows:

• MEMEME Smooth Boost
  • Shampoo (400 ml): ¥1,540 (tax included)
  • Treatment (400 g): ¥1,540 (tax included)
  • Shower Veil Treatment (180 ml): ¥1,540 (tax included)
• THE ANSWER
  • Around ¥1,700 (varies by volume)
• melt
  • 480 ml: ¥1,760 (tax included)

Even taking price per volume into account, MEMEME is priced as the most affordable option in Kao's high-premium lineup.

While it adopts a pop package design that overturns Kao's public image of being "serious and solid, but safe and unremarkable for a drugstore product," what's inside reflects extremely advanced technology: it is free of quaternary ammonium salts, uses a lamellar structure, and contains Kao's proprietary lipid repair ingredients (an 18-MEA derivative and a pseudo-ceramide).

The "MEMEME Smooth Boost Series" is an extremely well-crafted choice, in terms of both cost performance and functionality, for people who don't want their hair weighed down, those looking for a natural silky feel and easy finger-combing, and users with sensitive skin who put low irritation to the scalp and skin above all else.