What Is Low Porosity Hair? Trichologists Weigh In (2025)

Does your hair feel like it’s perpetually thirsty, no matter how much conditioner you slather on? Or maybe it seems like products just seem to sit on top of your hair, leaving you with a chalky, greasy or sticky film. If that’s the case, you might be dealing with low porosity hair. The good news: Understanding your hair’s needs is the first step to reversing the problem. Here, trichologists break down what is low porosity hair, including everything from the signs to the solutions to reversing it, so your hair will look and feel its best.

What is hair porosity?

“Hair porosity is the hair’s ability to absorb and retain moisture,” explains hairstylist and trichologist Gabby Henderson. “It’s determined by the structure of the hair cuticle, the outer layer of the hair shaft.”

According to Kimberly Vaughn, certified trichologist and CEO of HPIHair, hair porosity is important to the strength and overall appearance of the hair.

There are three main levels of porosity:

1. Low porosity: The cuticle is tightly sealed, making it difficult for moisture to penetrate. This type of hair tends to be dry, lacking luster and shine. It’s also resistant to coloring and prone to product buildup, says Vaughn.
2. Normal porosity: The cuticle is slightly raised, allowing moisture to enter and exit the hair shaft as needed.
3. High porosity: The cuticle is raised or damaged, allowing moisture to enter and exit quickly, but this also makes hair prone to dryness, says Vaughn. “Hair strands easily break become stretchy and feel more elastic when the hair is in a high porosity state.”

What causes low porosity hair?

Most commonly found in people with thicker, coarser hair, low porosity hair can occur in any hair type: straight, wavy, curly or coily. Many other factors play a significant role in having low porosity hair. They include things like genetics, sun exposure or chemical treatments, explains Henderson.

How to test for low porosity hair

Want to know if the issues you’re experiencing are due to low porosity hair so you can treat it accordingly? Try this easy test to find out!

Take a clean strand of hair and drop it into a glass of water. If it floats and takes a long time to sink, your hair likely has low porosity.

Watch this TikTok from @paulmitchell to see the test in action.

How to treat low porosity hair

The goal in treating low porosity hair is to gently lift the cuticle to allow moisture in. This involves using the right products and techniques.

Look for these ingredients

For low-porosity hair, look for haircare products that have ingredients to help gently lift the cuticle to allow moisture to enter. Some ingredients include:

• Humectants that attract moisture to the hair. Common humectants that you’ll find in hair products are glycerin, niacinamide and hyaluronic acid.
• Lightweight oils that can help seal in and moisturize hair without weighing it down. A few to keep any eye out for are argan, jojoba and marula oils.

Henderson’s tip: Give yourself a hot oil treatment using a lightweight hair oil, then wash your hair with a shampoo containing a humectant like niacinamide. You can find it in Nioxin Hair Fall Defense Shampoo, which also contains caffeine, sandalore and lauric acid—these ingredients stimulate hair follicles and nourish the hair.

Steam your hair

“The use of a warm steamer during moisturizing treatments will assist in deep penetration and longer-term health benefits for the hair,” says Vaughn. (Click through to learn how to give yourself a steam treatment for hair).

Apply a DIY mask

A natural DIY moisture mask using humectants like honey and aloe vera work well. Since porous hair absorbs treatments best when the hair is slightly moist, Vaughn suggests shampooing hair as normal, then lightly towel-dry hair before applying the moisture mask. Work the product through the ends of the hair, then apply a steam or warm, moist towel over the hair. Let sit for 10 minutes before rinsing.

Try an apple cider vinegar (ACV) rinse

Mix 1 part ACV with 3 parts water and use as a rinse after shampooing. “The acidity helps to slightly open the cuticle and balance pH,” explains Henderson.

Avoid protein-heavy products

Low porosity hair tends to be more protein-sensitive, explains Henderson, so avoid products with lots of protein.

Opt for lightweight products

“Thick oils, butters and heavy creams can lead to build up and make it harder for moisture to penetrate the hair shaft,” says Vaughn. The key is to keep your hair well-moisturized with light, effective products and to avoid overloading it with heavy ingredients.

Stay away from silicones

They can also create a barrier on the hair, making it difficult for moisture to penetrate, says Vaughn. Instead, look for silicone-free products or those with water-soluble silicones.

Opt for sulfate-free options

Sulfates can strip the hair of its natural oils, making it even more difficult for low porosity hair to retain moisture. So it’s best to avoid products that contain them.

Keep heat styling to a minimum

Henderson cautions against excessive use of high-heat styling tools like flat irons or blow dryers. Why? This can further damage the hair cuticle, making it more difficult to manage.