We’re wrapping up another year of cutting-edge hair science with a roundup of our most popular Science Sunday stories. Over the past 12 months, we’ve uncovered the truth about clean hair, hydration, and the secrets of going gray. Catch up on our favorite articles, trending buzzwords, and key takeaways below.

why does hair go gray?

Hair graying is a natural process that occurs as we age. It’s caused by the loss of melanin due to oxidative damage during melanin production, and stem cell loss in hair follicles. Since melanin naturally provides photoprotection—AKA defense against ultraviolet (UV) radiation— melanin loss impacts hair texture, strength, density, and growth rate.  

key vocab: Melanin

The pigment that determines hair color. Produced by melanocytes, the type, size, and amount of melanin in each fiber gives your hair its color.

Read the full article here.

why natural ingredients aren’t necessarily better for you (or the planet)

Natural ingredients are often marketed as safer, but undergo no safety testing, can cause allergic reactions, and harm the environment through resource gathering. Synthetic biology offers safer, purer, and more sustainable alternatives, enabling the creation of high-performance ingredients and innovative products like K18PEPTIDE™ and patented odorBIND™ smart-release biotechnology.

key vocab: Synthetic Biology

Synthetic biology is a subset of biotechnology that allows us to engineer the genetic code of organisms and living systems to produce more sustainable versions of natural ingredients, or novel high-performance ingredients with unique benefits.

Read the full article here.

all hair is hair—and the same—on the molecular level

Despite differences in hair shape and color, all hair shares the same keratin structure at the molecular level. That means it shares the same fundamental structure and endures the same damage. And that means that all hair types can use molecular repair biotech to reverses damage on the deepest innermost layers of hair. 

key vocab: Polypeptide Chains 

Chains of individual peptides made of amino acids that are bound together by peptide bonds. These long, fibrous keratin polypeptide chains weave together like a rope to form larger structures, providing your hair with its core strength and elasticity.

Read the full article here.

what is optimal hair hydration?

More often than not, moisturizing ingredients in haircare are merely surface treatments–working  to minimize the appearance of damage caused by high porosity or water retention, rather than repairing it. This creates damage deep within hair and can challenge the integrity of its protein structure.

key vocab: Hair Porosity

Porosity describes the ability of hair to absorb and retain moisture, determined by the overall damage level of the cortex and the condition of cuticle cells on the surface of hair.

Read the full article here.

the science of clean hair

Hair starts getting dirty immediately after washing due to sebum buildup, dust, and pollutants. Regular washing is key to maintaining healthy hair and scalp, but over-washing it can strip away the natural protective oils, leaving hair and scalp vulnerable. K18's shampoos clean without stripping color or essential moisture, while prepping your hair to receive our patented reparative K18PEPTIDE™.

key vocab: Surfactants

Surfactants, short for "surface-active agents," help oil and dirt mix with water, allowing buildup, contaminants, and impurities to rinse away. They can also impact your shampoo's thickness and how quickly it lathers, in addition to helping suspend other active ingredients like water, preservatives, and moisturizers

Read the full article here.

the science of hair drying