Decoding your curls can be confusing, but it’s a necessary step that will allow you to make informed decisions when it comes to what type of products you need.
Whether you are someone who has tight coils, dehydrated curls, or an array of textures, you want to understand how to best manage your mane.
If you’re following the standard hair types 1 through 4 with subcategories of A to C, you can discover your curly hair type and see which products will work best. Especially for those who have dense strands or straw-strung coils, understanding your hair is essential to a successful regimen.
The Science Behind Curly Hair Types and How it Behaves Structurally
There are many curl types, and each has a unique behavior structurally. The physical characteristics of human hair vary considerably among different racial groups.
Caucasian, European, Afro, African-American, Latin, and Asian hair are the most commonly known groups of hair types characterized based on their different hair features.
Curly hair types differ depending on hair diameter, curliness, mechanical strength, color, and even hair density. They vary in terms of their curl pattern and curl type, particularly when it comes to appearance.
In recent years, hairs have been classified/divided into curl categories or degrees of curliness based on the extent of curliness.
The curly nature of human hair has been a topic of great interest to hair experts and customers in recent years. Over the previous two decades, hair scientists have studied why curly hair behaves differently from other types of hair and what causes it to do so.
Let’s look at some historical views and science behind curly hair and answer the questions as to why some of us have curly hair and why curly hair looks and behaves differently.
Historical background of curly hair types
In the early days, fundamental physical and chemical analysis was the only tool to examine a hair fiber, and the focus had only been on European Caucasian hair.
Later, research papers isolated the distinctions among ethnic hair fibers, mainly highlighting the hair diameter, mechanical strength, breakage, and amino acid analysis to determine the chemical nature of Caucasian and Afro hair.
No attempt had been made to thoroughly examine the curl pattern and broaden the scope of the study. To the best of their effort, the first research report was published in 2003 titled “Hair shape of curly hair” in the Journal of the American Academy of Dermatology.1
The paper discussed the biological aspects of the hair follicles and the chemical processing inside hair follicles that lead to different curl patterns.
Later in the 2000s, a series of papers were published in prominent dermatological and cosmetic science journals describing the latest efforts to explore the reasons for curliness.
In 2003, French scientists, led by Geneviève Loussouarn, first described a classification technique for human hair. The author published his findings in Human Biology and International Journal of Dermatology in 2007.2-3
They developed a method to measure the curve diameter of the curl. Hair samples from all over the world were collected, examined, and then compared for the curl degree among different hair origins and ethnic groups.
As time progressed, multiple studies have been published and the focus has been to figure out the structural reasons for curly hairs.
Structural feature of curly hair types
Hair has three distinct layers:
Cuticles – the outermost
Cortex – the middle region
Medulla – the innermost region
In general, we consider hair as cylindrical, however, this is not true.
Hair is elliptical in shape and its ellipticity is related to its degree of curliness and is due to different cellular arrangements within it.
According to microscopic studies, the site at which curly hair originates is in the cortex. The hair cortex is not uniform for curly hair, as shown by a transmission electron microscope.4
In the cortex, there are two types of specialized cells, ortho-cortical and para-cortical cells.
The curl of hair is determined by the different ratios of ortho-cortical and para-cortical cells.
The hair is curly due to the varying ratios between the ortho and paracortical cells.
In hair with a high ratio of ortho-cortical cells to para-cortical cells, the hair is more round and straight, while a high ratio of para-cortical cells makes hair more elliptical and curly.
These variations in cellular ratio define the actual curl pattern, definition, and number of curls per unit length.5-7
How Curly Hair Types Behave: Porosity, Elasticity, Hair Moisture Content
Scientific literature has widely discussed the fundamental parameters of how curly hair behaves. For example, the porosity, elasticity, and moisture content.
As described above, curly hairs are elliptical (oval) and mechanical studies have shown that curly hair is weaker than straight Asian or Caucasian hair.
Furthermore, hair porosity may increase with an increasing degree of curliness. This means straight hair is less porous while curly, wavy, and African coily hair is more porous and hence vulnerable to breaking easily.
In addition, when comparing curly hair to straight hair, curly hair was found to have lower moisture level, and this was also correlated to the scalp moisture level.8-9
So, what does this data tell us?
Structural studies and physio-chemical data highlight that curly hair is different from straight hair. In other words, curly hair is distinctly different from straight hair.
Due to the fact that curly hair is different from straight hair, it has different needs and therefore demands specially crafted and customized formulations specifically made for curly hair.
The special needs of curly require a certain level of moisturizing and polymeric materials to achieve its desired curl definition, body, and volume.
As a result, the trend has been to increase curly hair care products in the market.
Now that we know a bit more about the science of curly hair, it’s easier to see why certain ingredients and formulas work better for some curly hair types.
Scalp health also matters
To determine a hair care treatment or product, most consumers focus only on curly hair type or classification.
While this is a good starting point, it’s not the only factor to consider when selecting products for curly hair.
One important factor that consumers often ignore or overlook is the condition of their hair and scalp.
Ever heard the saying that a healthy scalp equals healthy hair? The condition of the hair is directly affected by scalp surface roughness, sebum production or secretion rate, and pH level.
Hair requires nourishment which includes protein, minerals, and lipids (oil) to grow healthy and produce shine and gloss.
Hair extracts all these vital nutrients from scalp tissues. Healthy normal blood circulation is the key to healthy hair follicles and normal follicular activity.
Dandruff, product residue, and pollution particles can accumulate on the scalp surface, forming an undesired layer that inhibits normal biological function.
All hair types are affected by these factors including curly hair.
It is critical to examine both hair and scalp health in addition to hair classification and type before starting a hair care regimen.
Put Your Curls to the Test
You may think you know your hair by just looking in the mirror, but there’s a lot more that goes into knowing your strands.
Think of the structure of what makes up a hair. There’s the cuticle, the cortex, and the medulla.
Depending on the status of each layer, you can begin to determine how your hair reacts and what that means in terms of best care solutions.
One simple way to test your hair is by checking the porosity levels. The porosity affects how well the hair absorbs oils and retains moisture.
For understanding curly hair types, knowing the hair’s porosity is especially important because you want to ensure the products chosen are compatible. Even if it seems like the most incredible product for curls, it’s a possibility that your hair won’t react the same as others.
While a certain conditioner may be known for quenching dry curls, there’s a chance your hair’s porosity levels won’t match up well for absorption.
There are three different porosity levels ranging from low to high.
- Low: Cuticles are close together
- Medium: Cuticles are less tightly bound
- High: Cuticles are widely spaced
Testing for porosity can be done with a quick experiment using just a glass of water. With clean and dried hair, put several strands of hair into the glass of water and observe how they react.
Low porosity: Strand remains floating on top of the water
Medium porosity: Strand floats somewhere in the middle
High porosity: Strand quickly sinks to the bottom of the glass
Once you’ve identified the porosity level, you can feel more confident in the products you choose.
Although there is no perfect guide when it comes to caring for various curly hair types, this discovery gets you one step closer to healthier and more manageable curls.
Beyond porosity and the science behind hair, identifying your curl type can have a significant impact on how you choose best care practices.
While there are so many different textures in the curl world, once you know the category your hair best identifies with, you become a part of a special curl community.
Identifying Each Curly Hair Type
It’s a beautiful sight to see curl friends come together and share routines and products. But if you can’t strongly identify your curly hair type, you may be missing out on opportunities for growth, strength, and styling.
Just like finding your personality type, your curl type is an important part of your hair journey and will become a huge deciding factor on product purchases.
The Andre Walker Hair Typing System was created in the 1990s and is the most widely used system to classify hair. Andre Walker, the hairstylist of Oprah Winfrey, created the method.
Naturally Curly’s curl type system focuses on curly hair types 2 (wavy), types 3 (curly), and types 4 (coily). The sub-classifications – from A to C – are based upon the diameter of the wave, curl, or coil.
Each hair type is broken down into three subcategories that highlight the particular patterns incorporated in curly hair. Depending on your curl type, it will make a huge difference in the products you buy.
A recent study by online beauty platform, Texture Media, has revealed that women with curls spend 100% more on hair care items and are less likely to go to a salon, preferring to splurge on an array of products to tame their textured crowns.
See what category your hair falls in and what products will be best based on these guidelines.
Product recommendations are specific to each person and their curl type, so it’s important to know what you’re working with before making a purchase.
If you have tight coils, for example, you will want to look for products that define and elongate your curls without weighing them down.
Conversely, if you have curly hair that is dehydrated, you want to look for moisturizing products that will hydrate your curls without adding any additional weight.
Here’s a breakdown to see if you fall under these curly classifications. I’ve also provided some product suggestions for each curly hair type.
Please keep in mind that these are only guidelines. They’re intended to serve as a starting point to help you discover the products that best suit your specific curly pattern.
You may not know what works for your hair until you’ve tried it. It’s all about experimenting and seeing what works for you.
Type 2 Hair:
It’s best to use products that will not weigh your hair down. Try foams and mousses, gels, and cream-gels. Apply a foam or mousse to your roots to enhance them. Also, look for shampoos and conditioners that won’t weigh your hair down, but adds some volume.
2A Hair Type
This hair type is the loosest out of all curly hair types with S waves throughout. While it may seem easier to manage, this curl type requires careful product selection to avoid weighing the hair down.
2B Hair Type
With a little more wave than 2a, this curl type also holds onto a lot of product, which can weigh the hair down. This hair is also more prone to frizz.
2C Hair Type
For this pattern, the waves are more defined S waves throughout with most potential for frizz. This hair type can be introduced to heavier products that previous patterns.
Product Suggestions for Type 2 Hair
Conditioner: MopTop Daily Conditioner
Co Wash: Briogeo Be Gentle, Be Kind Co-Wash or As I Am Coconut Co Wash
Leave in Conditioner: BRIOGEO Farewell Frizz Rosarco Milk Leave-In Conditioner or Giovanni Direct Leave in Conditioner
Deep Conditioner: As I Am Hydration Elation
Type 3 Hair Type
For curl definition and minimal frizz, use leave-in conditioners, curl creams, mousse, and or gel. Add a deep conditioner to your regimen to retain elasticity and moisture.
3A Hair Type
Each strand is fine, shiny, and falls with loose spiral curls compared to deeper curl patterns. This type of curly hair is easily defined even without heavy styling products and is prone to slight frizz.
3B Hair Type
In this subcategory, the hair has curls that are medium to tight ringlets, also known as springy curls. While this curl type is prone to exhibit multiple hair types together, it is also prone to frizz.
3C Hair Type
As the tighter pattern in the 3 category, this hair produces tighter coils than 3b. The curls of this hair type normally have a lot of texture with a corkscrew-like spiral. The coils can range from tight to loose.
Product Suggestions for Type 3 Hair Type:
Clarifying shampoo: Kinky Curly Come Clean
Conditioner: Briogeo Curl Charisma Conditioner
Deep Conditioner: Briogeo Don’t Despair, Repair! or Shea Moisture Raw Shea Butter Deep Treatment Masque
Oil: Righteous Roots Oils
4 Type Hair
To maximize moisture, use a leave-in conditioner, cream-based moisturizers, styling butter, and oils to seal in the moisture. Try styling methods like LCO/LCO, twists-outs, and braid-outs.
4A Hair Type
The curl pattern is small and you’ll notice small S-shaped strands that are tight with springy coils. Curls tend to be fragile and wiry.
Hair strands of this type typically shrink to half their length when dry, creating this rainbow shape. This type of hair has the most definitive curl pattern of the Type 4 hair category.
4B Hair Type
This hair incorporates a sea of Z coil (crimpy) curls, which is generally coupled with compressed and S-shape coils. It is also less defined than Type 4A curls.
4C Hair Type
As the tightest curl pattern, each strand is densely packed and coarse. The curl pattern of this hair type has more of a freeing definition, more shrinkage, and tight zig-zag pattern. It is also the most fragile of curly hair types.
Product Suggestions for 4 Hair Type:
Clarifying shampoo: Kinky Curly Come Clean
Conditioner: Camille Rose Moroccan Pear Conditioning Custard
Detangler: Soultanicals Knot Sauce Coil Detangler
Oil: Righteous Roots Oils
- Bernard, B. A., Hair shape of curly hair. J. Am. Acad. Dermatol. 2003, 48 (6, Supplement), S120-S126.
- De La Mettrie, R.; Saint-Léger, D.; Loussouarn, G.; Garcel, A.; Porter, C.; Langaney, A., Shape variability and classification of human hair: a worldwide approach. Human biology 2007, 79 (3), 265-281.
- Loussouarn, G.; Garcel, A. L.; Lozano, I.; Collaudin, C.; Porter, C.; Panhard, S.; Saint‐Léger, D.; de La Mettrie, R., Worldwide diversity of hair curliness: a new method of assessment. Int. J. Dermatol. 2007, 46, 2-6.
- Nagase, S.; Tsuchiya, M.; Matsui, T.; Shibuichi, S.; Tsujimura, H.; Masukawa, Y.; Satoh, N.; Itou, T.; Koike, K.; Tsujii, K., Characterization of curved hair of Japanese women with reference to internal structures and amino acid composition. J. Cosmet. Sci. 2008, 59 (4), 317-332.
- Bryson, W. G.; Harland, D. P.; Caldwell, J. P.; Vernon, J. A.; Walls, R. J.; Woods, J. L.; Nagase, S.; Itou, T.; Koike, K., Cortical cell types and intermediate filament arrangements correlate with fiber curvature in Japanese human hair. Journal of structural biology 2009, 166 (1), 46-58.
- Cloete, E.; Khumalo, N. P.; Ngoepe, M. N., The what, why and how of curly hair: a review. Proceedings of the Royal Society A 2019, 475 (2231), 20190516.
- Ezawa, Y.; Nagase, S.; Mamada, A.; Inoue, S.; Koike, K.; Itou, T., Stiffness of human hair correlates with the fractions of cortical cell types. Cosmetics 2019, 6 (2), 24.
- Syed, A. N.; Syed, M. In Curly Hair: Structure, Properties, and Care, Society of Cosmetics Chemists, 75th, NY, USA, NY, USA, 2021.
- Camacho‐Bragado, G.; Balooch, G.; Dixon‐Parks, F.; Porter, C.; Bryant, H., Understanding breakage in curly hair. British Journal of Dermatology 2015,173, 10-16.