Short on time? Here’s the scientific gist of it. Products with slip make hair easier to manage, smoother to brush through, and less tangled - meaning less breakage. There’s a great variety of ingredients that have been traditionally used for slip which can be grouped into a few categories, each with their own benefits and drawbacks. Selection of intentional biotech-produced ingredients, including the biomimetic polysaccharide in K18 DAMAGE SHIELD protective conditioner, can provide slip without contributing to significant product buildup.

got time? here’s the deeper dive.

Brushing out pesky tangles and knots can be a pain, so you may reach for conditioners or oils to ease up the process. These products create “slip,” or increased lubrication of the hair fiber, decreasing friction and minimizing mechanical damage. But what causes this slippery effect, and what impact does it have on hair health? Read on to find out.

why does hair need slip?

Brushing, combing, and styling can cause wear and tear, aka mechanical damage, to the hair fiber. It can also occur when you lather your hair with shampoo, as the hair fibers rub against each other and are exposed to detergents (the ingredients in shampoo that remove product buildup and dirt). Shampoo can also strip away the sebum, or protective natural oils produced by your scalp, which further increases friction and tangles.

What does mechanical damage do to the hair’s layers? All of this gradually chips away at the hair’s outer cuticle layer, lifting and degrading the overlapping tile-like cuticle cells, decreasing smoothness, softness, and shine. When hair is undamaged and in a dry state, the cuticle scales lay smooth and flat. When hair is wet, the cuticle tiles swell and raise or “open,” making hair more likely to snag and get tangled, increasing the likelihood of breakage. Stripping away the cuticle also leaves the cortex exposed to damage, impairing the hair's structural integrity and increasing breakage. Erosion of the cuticle makes it easier for water to enter and exit the hair strand, increasing the likelihood of frizz and dryness. When the cuticle is stripped away entirely with extreme damage, the interwoven strands of keratin that makeup hair’s inner cortex can unwind, causing split ends.

how to prevent mechanical damage

Maintaining slip when hair is both wet and dry is crucial. Even though the cuticle is most vulnerable when wet, tangling and breakage occur in both wet and dry states. Cosmetic ingredients like polymers, emollients, and oils provide slip to detangle hair, decrease friction between strands, and prevent mechanical damage. These ingredients primarily work on the surface of hair to temporarily moisturize the hair, 

 improving shine while softening and smoothing the cuticle by creating a uniform layer of protection. This allows brushes, styling tools, and individual hair fibers to easily glide past one another, lessening tangling and breakage during styling. 

Breakage can occur when tangles are combed forcefully, so a wide-tooth comb or finger combing should be used to carefully detangle your hair. When hair is dry, that’s when most of the mechanical manipulation, or styling, happens. Using oil on dry hair can also create slip to minimize tangling and breakage during styling. 

how slip is tested

To determine if a product effectively adds slip to the hair, scientists utilize the Combing Force Test which measures the amount of force needed to drag a comb through hair tresses. It is expected that conditioners decrease the force required to comb through the test tresses, as it smooths the cuticle and decreases the number of entanglements between fibers. This test is performed on wet and dry hair for conditioners, as long-lasting slip is just as important as right after it is rinsed out. So what ingredients add slip to hair? Let’s break it down. 

polymers for slip

Polymers coat and adhere to the proteins on your hair to provide thermal and mechanical damage protection and make hair soft and smooth. These polymers are most commonly either cationic, nonionic, or silicone-based.

Cationic polymers are one of the most effective types of polymers. Hair proteins are naturally negatively charged while cationic polymers are positively charged, which attracts the polymers to the hair. Shampoos typically contain negatively charged ingredients that can increase the negative charges on the surface of hair. Cationic polymers in conditioners can neutralize these negative charges to minimize flyaways caused by the repulsion between negatively charged hair strands. In some cases however, these polymers may lead to buildup on the surface of hair, especially on damaged hair which carries more negative charges. 

Nonionic conditioning and cleansing polymers are hydrophobic (water-disliking) in a dried state or prior to application and hydrophilic (water-liking) in a hydrated state or  when applied to wet hair. This allows people to easily wash away excess product without leaving a heavy residue on the hair. However, this can also leave the hair without a long-lasting protective barrier

Silicone polymers are insoluble in water, and form a smooth film on the hair, dramatically increasing slip between hairs and decreasing the mechanical force associated with combing. They also provide thermal protection and can increase color longevity in dyed hair, making them one of the best conditioning agents for slip and protection. The downside? Some of this type of polymer are more substantive, or persistent, and subsequently harder to rinse off, which may lead to buildup on hair. 

oils for slip + frizz-fighting

Regular application of hair oils, like coconut, almond, sunflower, and castor oil, as well as oil-like emollients like squalane, can provide slip to increase resistance to breakage, prevent split ends, and moisturize scalp skin when used in moderation to protect hair follicles and maintain healthy growth.

Coconut oil can penetrate the cuticle due to its size and nature to reduce cuticle swelling, lifting, and breakage when your hair is combed or brushed. Most other oils do not penetrate the hair shaft but can provide a lubricating film on the surface to reduce friction and mechanical damage. Since oil-treated hair does not absorb excessive moisture, it decreases frizz. Oil-treated hair can also retain higher moisture at lower humidities, preventing dryness.

the missing link: buildup + damage

Polymers and oils can provide slip to smooth, detangle, and improve the appearance of hair, but these ingredients used in excess can weigh hair down and cause buildup over time. They also fail to address the root cause of dull, dry hair: damage.