Nov 8, 2019

What Is A Hair Cuticle?

Let's learn more about your hair's first line of defense against damage ⚔️

To understand what a hair cuticle is, it's important to first know a bit more about basic hair anatomy (which is WAY more fun than the Anatomy class you took in high school, we promise!)

Hairs are made up of 3 basic parts:

the cuticle (the protective layer which we're learning about today)

the cortex (the thickest layer, and also where the majority of the pigment is concentrated)

the medulla (the very thin inner layer -  some hairs don't even have it!)

Hair is structured so that the cortex and the medulla make up the core of the hair strand, and the cuticle surrounds and protects them  from outside physical and chemical stress

Protection is a big job so the cuticle is a complex layer - it's made up of several scales that are stacked on top of each. These scales point downwards, away from your roots, and are shaped to limit friction between individual hairs. Close up, they look like roof shingles or scales on a fish, and move against each other so that your hair is able to bend without flaking off scales. Cool, right?

⭐Since your cuticle is the most tactile part of your hair, you can experience the shape of the scales yourself without a microscope. Pinch a strand of your hair and run your fingers from the hairs root to its tip. Smooth and easy? Now, do the same, but from the opposite direction: pinch from the tip of your hair and feel upwards. EEK, not as fun and kind of squeaky? That's the shape of your cuticles in action! When you run your fingers from your tip to your root, you run into the rough edges of the scaley layers of your cuticle- it doesn't feel good!

Cuticle Thickness and Racial Heritage

A thick cuticle typically means that the vulnerable parts of your hair (the medulla and cortex) are better able to withstand damage. This thickness often has a relationship with racial heritage. For example, people who are of Asian descent often have the most layered cuticles, while people who are of African descent have more thinly layered cuticles. This is one of the reasons why Afrotextured hair is so prone to damage despite how coarse each individual strand feels - the protective layer is not very thick, so it's more easily broken than other hair is.

What does a healthy cuticle look like?

A healthy cuticle is a smooth, closed cuticle with scales that are fully intact. This kind of a cuticle produces a lot of shine, since its scales are at the correct angle to reflect the largest amount of light, and feels very smooth to the touch.

What does a damaged cuticle look like?

A damaged cuticle is rough and dull, with scales that are either raised or stripped away, allowing for the vulnerable core of the hair to become damaged. Hairs that have damaged cuticles are also very tangly, as scales that normally point downwards have been raised so that they cause friction.


👋Hi! You've come to the right place! We'll start out by matching you to your own personal chemist, and then the journey of healthy hair will begin. Start here!


The Formulate Team

Caroline Schmidt
Tammy Lisi
Lead Chemist