What is Hair Cuticle? Everything You Need to Know

To understand how the hair cuticle affects the condition of your hair, it’s best to first explain a little about the physiology of hair in general. Every hair on your body grows out from a sac-like area at the bottom of your skin’s pores. That hole is known as a hair follicle, and it is there that a unique cluster of hair reproduction cells is located. Hair follicles are where your hair is formed and sprouts from.

No matter what the texture or length of an individual hair, all hair is comprised of three layers: the outermost cuticle, the inner cortex, and, in some cases, below the cortex is the medulla.


Hair Cuticle

The hair cuticle is made up of protein-based, flat hair cells that overlap one another like the shingles on a roof or the scales on a fish. Because the cuticle is on the surface, it’s the protective layer of the hair shaft. It’s affected by environmental factors (sun, humidity, water, pollution) as well as hair products that contain harsh chemicals.

hair shaft structure - hair cuticle, cortex, medulla

When you move your fingers from top to bottom over a single strand of hair, you’ll notice that it’s smooth. But when you move your fingers from the end of the shaft toward the root, you’ll probably notice that it’s “bumpier.” It might even make a squeaky sound as your fingers pass over it. That’s because your fingers are moving against the direction of the flattened hair cells of the cuticle layer.



The cuticle is the gateway to the cortex, and as such, it allows compounds and chemicals into the inner part of the hair shaft. Depending on what substance is applied to the cuticle, it will open or close, and the cortex will be nourished and moisturized (or damaged). The cortex is the layer that indicates the natural color, curl, texture, and thickness of the hair itself.

If you suffer from split ends, that means that the protective cuticle has been worn away, and the inner cortex is beginning to fray like the ends of a thread. This condition usually arises when your hair has been treated harshly from brushing too hard or exposure to the elements or chemicals.


Types of Hair Cuticles

Hair cuticles only come in two different types: healthy or damaged.

healthy hair cuticle vs damaged hair cuticle

Healthy Cuticle Vs. Damaged Cuticle

Your hair’s ability to absorb and retain moisture is determined by the structure of your hair cuticle. Some cuticles don’t absorb and maintain moisture easily, while others absorb moisture quickly, but don’t retain it for very long.


Hair Cuticles and Hair Porosity

Hair porosity is the determining factor regarding how well your hair cuticles will manage moisture. There are three types: high porosity, low porosity, and medium porosity.

High porosity hair has a lot of holes on the cuticle, which allows it to absorb moisture readily, but those same holes enable the moisture to be released too quickly. Excessive use of heat or chemical treatments can cause highly porous hair.

Low porosity hair has a hair cuticle with fewer holes and more densely compacted cell layers, making it more difficult to moisturize and hydrate. Low porosity hair is usually a genetically occurring condition.

Medium porosity hair is the ideal type because it’s the best of both worlds; it easily absorbs hydration and retains moisture.

If you’re not sure what kind of hair porosity you have, try the float test. Simply float a strand of hair in a dish. If it sinks, you have high porosity hair, if it floats, your hair is low porosity, and if it stays in the middle, your hair is normal porosity. Knowing what kind of porosity your cuticle has can help you take better care of your hair. Learn more about the differences between high and low porosity hair.


How to Open Low Porosity Hair Cuticles?

If you’ve determined that you have low porosity hair, there are several things you can do to open up the cuticle to help your hair stay hydrated:

  1. Pre-poo your hair with a rich, moisturizing hair mask BEFORE you wash it.
  2. Don’t over-wash your hair; it strips the hair of its natural scalp oils. Wash no more than once a week.
  3. Wash your hair with warm-hot water to open the cuticle.
  4. Use water-based hair products that won’t clog the cuticle.
  5. Use natural fruit and vegetable oils such as olive, avocado, or jojoba at least once a week.
  6. Cover your hair when you’re at home and during sleep to retain your scalp’s natural oils.


How to Seal High Porosity Hair Cuticles?

If your hair is high porosity, then you should also be moisturizing, but with different types of products:

  1. Use high-protein treatment masks that are rich, creamy, and emollient, at least once a week.
  2. Deep condition whenever you wash your hair with shampoo.
  3. Use products with heavier natural oils and butter, such as coconut, argon, and shea.
  4. Wash your hair with cool-lukewarm water.
  5. Rinse your hair once a week with apple cider vinegar, which neutralizes the hair’s pH and closes the cuticle.


Why Does the Hair Cuticle Get Damaged?

The hair cuticle is the part of the shaft that allows coloring products or hair perm products such as straighteners or curly perms to reach the cortex. Chemically speaking, an ingredient must be able to lift and penetrate the cells of the cuticle down to the cortex level to be able to change the structure or color of the hair permanently.

Once that happens, though, the effects are irreversible, and in the long run, damaging to the hair. That’s the price of beauty!


Can Damaged Hair Cuticles Be Fixed?

While there are many products on the market that promise to heal or fix damaged hair cuticles, most of them can only temporarily treat the situation. The fact is the only way to repair damaged hair cuticles once and for all is to cut or trim the damaged hair.

Still, there are some things you can do to rejuvenate damaged hair before deciding to cut it. These options come in handy, especially when you want to let your hair grow longer before trimming it.


How to Fix Damaged Hair Cuticles?

Unless you have textured or curly hair, don’t comb or brush it when it’s wet; it causes the strands to stretch and break, which leads to damaged cuticles.

  • After shampooing, use a normal conditioner, and then apply a moisturizing leave-in conditioner or frizz-reducing cream or gel.
  • Avoid using heating appliances such as blow dryers, curling irons, and straightening wands.
  • If you must blow-dry, keep the end of the dryer at least 18 inches from the hair, and use the cool air setting.
  • Wear your hair in a natural style that can be air-dried instead of blow-dried.
  • Don’t chemically straighten or perm your hair.
  • Don’t permanently color your hair, instead, use a topical wash-out rinse.
  • Avoid rubbing your hair vigorously with a towel. This action causes friction and can upset the hair’s cuticle.
  • Eat healthy foods that support hair growth and increased hair strength.
  • Get your hair trimmed regularly.


Final words

Damaged hair cuticles are the primary reason your locks become dry and unmanageable, because when they’re open, the cortex is more susceptible to moisture loss and breakage. Do whatever you can to reduce the external factors that wreak havoc on your hair, and also remember to eat a healthy diet.

We live in an age of cultural diversity where many people have lots of different opinions about the way the world should operate. But there’s one thing that everyone can agree on, regardless of gender, race, age, nationality, or economic status: no one wants damaged hair!

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