How to Understand the Porosity of Curly Hair

Have you ever applied an ultra-hydrating mask only to end up with dry hair anyway? Or used a lightweight product and immediately felt your curls weighed down? If so, the answer lies in your hair porosity.

Porosity determines how well your hair absorbs and holds onto moisture, and understanding it can make the difference between an effective routine and a series of frustrating trials.

In this article, you’ll discover what hair porosity is, how it affects your curls, and which tests you can use to finally understand it—so you can give your hair exactly what it truly needs.

Hair porosity is the hair shaft’s ability to absorb and retain moisture. It depends on how the cuticles—the outermost layers of the hair—are arranged and how easily they allow moisture and treatments to penetrate.

There are three levels of porosity:

• Low porosity:
  The cuticles are tightly closed, making it difficult for moisture to penetrate, but once it does, it is retained very well. Hair tends to dry slowly, and products often sit on the surface rather than being absorbed.
• Medium porosity:
  The cuticles are slightly raised, allowing hair to absorb and retain moisture efficiently. This is considered the ideal porosity level.
• High porosity:
  The cuticles are very open (often due to chemical or mechanical damage), which allows hair to absorb moisture quickly—but also lose it just as fast. Hair often feels dry, frizzy, and difficult to manage.

Porosity does not depend on curl type, but on the structure of your hair, which can be influenced by genetics as well as chemical and heat treatments.

When it comes to a Curly Routine, hydration and porosity go hand in hand. Knowing your hair porosity allows you to choose products and techniques that help your curls absorb and retain the right amount of moisture.

Low Porosity Hair: How to Improve Moisture Absorption

If you have low porosity hair, it means the cuticles are very compact and do not easily allow moisture to enter. This often results in conditioners and masks sitting on the surface rather than penetrating the hair fiber.

To improve moisture absorption, it helps to:

• Apply treatments with heat. Steam from the shower, a flaxseed heat cap, or a warm towel can gently open the cuticles, allowing hydrating products to penetrate more effectively.

• Choose lightweight, water-based formulas rich in humectants such as glycerin, aloe vera, and hydrolyzed proteins, which attract and retain moisture without weighing the hair down.

• Use a clarifying shampoo periodically to remove product buildup, which can make hair even more resistant to hydration.

High Porosity Hair: How to Retain Moisture Longer

If you have high porosity hair, the main challenge is retaining moisture. Water and hydrating products are absorbed quickly—but they also evaporate just as fast, leaving hair dry and damaged.

To prevent moisture loss, try these strategies:

• Seal hydration with lightweight oils and butters, such as jojoba oil, argan oil, or shea butter. These help create a natural barrier that slows moisture evaporation.

• Use the LOC Method (Liquid – Oil – Cream): first apply a liquid hydrating product, then an oil to seal in moisture, and finally a nourishing cream to protect the hair shaft.

• Avoid excessive heat styling, such as frequent blow-drying or flat ironing, which can further lift the cuticles and worsen moisture loss. Opt instead for diffusing on low or medium heat.

Medium Porosity Hair: How to Maintain Balance

If your hair has medium porosity, you benefit from a healthy balance between moisture absorption and retention. This makes it easier to achieve elastic, well-defined curls—but maintaining this balance is key.

To do so:

• Alternate hydrating and protein-based products to maintain strength and elasticity. A balanced mix of humectants, emollients, and proteins helps prevent dryness and damage.

• Protect your hair at night by using a satin or silk pillowcase to reduce friction and preserve moisture.

• Adjust your routine with the seasons: during humid periods you may need less hydration, while in drier months it’s helpful to increase the use of emollients to protect the hair shaft.

Determining hair porosity can seem complicated, but there are several tests that can help you better understand how your hair reacts to water and hydrating products. Some tests are quicker and more intuitive, while others are more reliable. Here’s a detailed overview of the most commonly used ones.

1. The Water Glass Test

One of the most popular methods is the water glass test. The process is simple:

• Take a clean, dry strand of hair, preferably one that has fallen out naturally.

• Fill a glass with room-temperature water.

• Drop the hair into the water and observe what happens for a couple of minutes.

According to this method:

• If the hair floats, it indicates low porosity.

• If it stays suspended in the middle, it suggests medium porosity.

• If it sinks quickly, it points to high porosity.

However, this test has several limitations. Product residue, natural scalp oils, and even the type of water used can affect the results. In addition, porosity is not uniform throughout the hair: roots may have a different porosity than the ends, so a single strand is not always representative of your entire head of hair.

2. Water Absorption Test

A more reliable method is to observe how your hair interacts with water. To do this:

• Take a clean, dry section of hair.

• Spray a small amount of water onto it and watch how it reacts.

What happens next?

• If the water beads up and slides off, you likely have low porosity hair.

• If the water is absorbed slowly, you have medium porosity hair.

• If the hair absorbs water immediately but dries very quickly afterward, you have high porosity hair.

This test is more accurate because it reflects your hair’s real ability to absorb and retain moisture. Still, it’s best to test multiple sections of your hair to get a complete picture.

3. Drying Time Test

Another useful indicator is how long your hair takes to air-dry after washing:

• Low porosity hair: takes several hours to dry, especially at the roots. Water seems to remain “trapped” in the hair and evaporates slowly.

• Medium porosity hair: dries at a balanced, moderate pace.

• High porosity hair: dries very quickly—sometimes in less than 30 minutes—because moisture escapes easily.

This test works best when combined with the others to give you a clearer understanding of your hair’s porosity.

4. Product Absorption Test

The way your hair reacts to products can also reveal a lot about its porosity. After applying conditioners, masks, or leave-in products, observe how your hair behaves:

• Low porosity hair: products tend to sit on the surface and don’t absorb easily, sometimes leaving visible residue.

• Medium porosity hair: absorbs products evenly and retains moisture well over time.

• High porosity hair: absorbs products immediately but feels dry again shortly afterward and often needs frequent reapplication.

This test is especially useful because it mirrors real-life hair care conditions, offering practical insight into how to best treat your curls.

Which Test Should You Choose?

No single test can definitively determine your hair porosity. The most effective approach is to combine several methods and observe how your hair behaves over time.

A helpful tip is to monitor your hair for a few weeks, paying attention to:

• How it feels and looks after washing.

• How it reacts to hydrating products and oils.

• How long it takes to dry naturally.

By putting all this information together, you’ll be able to identify your porosity more accurately and choose the routine that truly suits your curly hair.

Now that you understand your hair porosity, you’re ready to build a personalized Curly Routine and fully enhance the natural beauty of your curls!