All products featured on Allure are independently selected by our editors.

However, we may receive compensation from retailers and/or from purchases of products through links in this article.

Read on for the highlights.

Image may contain Hair Human Person and Black Hair

What Makes Hair Curly?

Keratin is distributed via the follicle and provides structure to human hair.

So what dictates the shape of our follicles?

Philip Kingsley Elasticizer Deep-Conditioning Treatment

How Are Curls Classified?

These charts typically range from 2, which is wavy, through 4, which is coily.

For this reason, Douglas recommends using curl pattern charts as a starting point only.

TPH by Taraji Never Salty

When it comes to truly understanding curls and coils, other factors include porosity (were getting to that!

Can Curl Patterns Change?

In short, yup.

A bottle of Mielle Organics Avocado Moisturizing Hair Milk on a purple background

Over time, curl patterns can become tighter or looser.

Graying is also associated with a change in curl patterns.

Damage especially heat damage can also have a major impact on curls.

Tangleteezer The Original on colorful background — detangler hairbrush winner in Allure Best of Beauty Awards 2019

The more you manipulate your hair, the more its structural integrity breaks down.

The only time hair is actually able to heal itself is when its in liquid form under the scalp.

Its the aggregation of proteins and nutrients under your scalp, explains Doulgas.

Image may contain: Box, Food, and Mayonnaise

In Douglas words, its all downhill from there.

What Is Hair Porosity?

Your hairs porosity describes how its cuticles absorb and maintain moisture.

Not Your Mother’s Curl Talk Frizz Control Sculpting Gel

Low porosity hair means your cuticles are compact and difficult to penetrate.

Each level has its own pros and cons, explains Douglas.

Curls are more delicate than straight strands due to the shape of the hair fiber.

Aquis Original Hair Turban

Because of this, curls tend to become damaged and dehydrated far more quickly than straight hair.

She encourages those who try this experiment to think of their hair like a boat.

In a boat, you want the bottom sealed up.

Dyson Supersonic Hair Dryer: A nickel and copper-colored hair dryer with matching attachments on a white background

Thats what makes the boat float.

How Should Curly Hair Be Washed?

Avoid harsh, stripping shampoos, especially those containing sulfates.

Ankh Rosemint Shampoo

Because while sulfates do a great job of cleaning hair, theyre also intense detergents.

As an alternative to sulfate-based shampoos, many members of the curly and natural hair communities co-wash their hair.

How Should Curls Be Conditioned?

Philip Kingsley Moisture Extreme Conditioner

The short answer is: deeply.

(This explains why the ends of curly hair tend to get particularly dry.)

So regular, deep conditioning is recommended for curly hair, especially on the lengths and ends.

Image may contain: Bottle, Human, Person, and Hair

Products with shea, cocoa, and murumuru butters keep curls soft and hydrated.

How Else Can Curls Be Protected?

Plus, silk results in less friction, which can create frizz.

A bottle of Kristin Ess Hair Curl Ultra Hydrating Curl Co Wash on a purple background

For the same reason, steer clear of rough-drying your hair with traditional towels.

Instead, gently blot curls dry with a microfiber towel or t-shirt.

How Does Heat Styling Affect Curly Hair?

Afro Sheen Crown Defining Curl Cream

Thats because heat alters the proteins that lock curls in their spiral shape.

…and you see all the little hairline cracks going through the window.

How Can Curls be Chemically Straightened?

Beleza Natural Humectant Oils

Theres no way to chemically straighten hair without sustaining some kind of damage.

This treatment can superficially straighten hair for up to three months, but it will eventually wash away.

Recently, though, many formaldehyde-free alternatives have become available.

These use glyoxylic acid or a derivative to achieve a similar smoothing effect.

Faux Curls

The grass is always greener, right?

Heres how to create the curls of your dreams even if youve got naturally straight hair.

So proceed with caution.

Remember those disulfide bonds we said determine the shape of your hair once its grown out of your head?

These include using thick products that can make hair stringy, or applying any product at the wrong time.

While youre at it, be sure to distribute the product evenly.

But if its humid or rainy out, you might want to reconsider your game plan.

Youre literally pulling the [hydrogen] off the hair, she says.

I layer that on and twist my hair into two strand twists, she says.

(Plus its size and shape makes it way easier to practice theplopping techniquefor drying.)

I just flip my head upside down and kind of scrunch the diffuser into my hair.

As for stylers, Jihan has been usingAfro Sheen Crown Defining Curl Creamnon-stop.

It makes my hair really nice and shiny, she says.

But enough about white men hiding from the legal ramifications of their actions.

About 30 years later, Charles Nessler set one of the first ever perms.

These curls enticed American women to start using hot rollers to style their own hair that way.

For the past couple of decades, the natural hair movement has been gaining even more steam.

Theres no denying curly hair requires a lot of TLC.

Explore moreScience of Beautytopics:

Listen to more episodes: