January 10, 2023
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Leo possesses more than 17 years of valuable experience as a researcher and lecturer within the fields of Biology and Genetics. Holding a PhD in Biology from the University of Buenos Aires, Argentina...
If you have low-porosity hair, you’re likely familiar with the struggle to find hair products that can truly penetrate your hair strands. The reason for this challenge lies in the unique structure of your hair cuticles, which are tightly packed together, much like fish scales. Here’s where the science kicks in:
The key to unlocking the potential of low-porosity hair lies in choosing oils with a low molecular weight. These specialized oils have smaller molecules, allowing them to maneuver through the compact structure of the hair shaft and penetrate the cuticles effectively.
To ensure you get the most accurate and effective advice, I’ve teamed up with a friend who is a hair scientist with a PhD in Cosmetic Chemistry. Together, we’ve pooled our expertise to bring you science-backed recommendations for the best oils to use on low-porosity hair.
By the end of this guide, you’ll have a comprehensive understanding of how oils affect low-porosity hair. We’ll also delve into the science of hair porosity, explore the benefits of using lightweight oils, and clarify the key differences between moisturizing and sealing oils.
The following oils have a low molecular weight, making them effective at penetrating the tightly bound cuticles of low-porosity hair:
Coconut oil is an excellent option for hair conditioning and treatment. Leading Hair Scientist, Yash K Kamath from TRI Princeton, (Princeton, NJ), collaborated in a series of experiments examining the penetration of coconut oil in the hair fiber.1,2,3
Studies using mass spectrometry and radio-labeling have shown that coconut oil effectively penetrates the hair.2,4 Compared to other oils, like mineral oil, coconut oil has a greater ability to reach the hair’s inner cortex. This may be due to its lauric acid content, which has a smaller carbon chain of just 12 fatty acids.4
As a result, coconut oil is highly recommended for low-porosity hair. It not only tackles dryness but also enhances the hair’s mechanical strength by bonding the inner fiber structures.4 This makes it an excellent long-term treatment for improving hair health and quality.
Moreover, it provides an exceptional sensory experience by imparting a velvety texture and unparalleled softness to your hair.
Virgin Olive oil is rich in mono-unsaturated fatty acids and has a relatively polar nature. These characteristics enable it to effectively penetrate the hair fiber. Additionally, it is rich in antioxidants, specifically tocopherols.7,8
Castor oil is unique among natural oils for its ricinoleic acid, content, which has a distinct chemical structure featuring a hydroxy group attached to the carbon chain.9 This gives the oil a polar nature and a somewhat sticky texture. Due to its polar qualities and mono-unsaturated fatty acids, castor oil is effective at penetrating hair fibers.5
Hair fibers have small pores on their surface that act as pathways for active ingredients to penetrate. These pores are situated between the layers of the hair cuticle.
Active cosmetic ingredients can enter these pores and be absorbed into the inner cortex of the hair. Numerous studies have investigated how emollients penetrate through these pores.15
The rate and volume of penetration (or amount of oil penetrated) depend upon the following factors:
The size of the active ingredient’s molecule needs to fit the opening in the hair cuticle for penetration to occur. Molecules larger than 1 nm won’t be able to penetrate, especially in untreated, virgin, low-porosity hair.
In chemically treated, damaged, or high-porosity hair, the cuticle pores are generally larger. This allows for easier penetration of larger cosmetic active ingredients.
When the hair is subjected to alkaline conditions or solvents, it swells, further enlarging these pores and allowing even larger molecules to pass through.17
The second factor influencing penetration is the shape of the active cosmetic molecules. Simply put, molecules with a symmetrical, round shape are more likely to penetrate the hair than those with irregular, uneven shapes.
Research shows that oils containing saturated fatty acids with regular shapes penetrate more easily compared to polyunsaturated oils, which have multiple unsaturated carbon chains.18
Polar molecules have opposite charges attached to the same molecule due to differences in electronegativity. Both oils and butter can be polar or non-polar, depending on their composition. Recent research shows that polar oils are generally more effective at penetrating hair, as they adhere better to hair proteins like keratin, which itself contains polar and non-polar amino acids.2
We’ve compiled a list of oils suitable for penetrating untreated, low-porosity hair. While many oils can penetrate hair fibers, the degree and speed of penetration can vary based on factors like the oil type and hair condition.
Polarity values for various oils
|Oil||Polarity Index (nM/m)|
|Liquid Paraffin (For reference)||53.0|
|Mineral Oil (For reference)||43.7|
|Coconut||Data not available|
Low porosity hair, often found in virgin, natural, or non-chemically treated types, has smaller internal pores than average. While it may look healthy, neglecting proper care can result in damaged ends and breakage. Managing this hair type can be challenging and requires a consistent and attentive care routine.
Have you ever wondered why you can have dry hair one day and oily hair the next? This variability is partially due to a characteristic known as ‘hair porosity.’ Simply put, hair porosity refers to how well your hair can absorb and hold moisture, as well as other substances like oils.
Understanding your hair’s porosity is essential for choosing the right products and techniques to keep your hair healthy and looking its best.21 Research has shown that hair porosity is linked to both the quality and strength of your hair fibers.22
High porosity hair is often weak and damaged due to factors like chemical treatments or heat exposure. In contrast, low-porosity hair has a tightly packed cuticle layer, making it strong but also water-repellent.21 Knowing these characteristics can guide you in tailoring your hair care routine.
When choosing the right oils for low-porosity hair, prioritize those with a lightweight molecular structure and high fatty acid content.
Not only do these light oils penetrate the hair shaft to deliver essential nutrients, but they also help low-porosity hair retain much-needed moisture.12 Heavier oils, on the other hand, can weigh down your hair and are less effective at providing moisture.23
It’s important to note that oils aren’t a universal fix; your unique hair type may respond differently, so experimentation is key.
To optimize your hair care routine, consider combining these oils with other synergistic products for a holistic approach to maintaining strong, healthy, and well-moisturized hair.
I highly recommend Righteous Roots Rx hair oil for a well-rounded oil blend solution. This blend is not only moisturizing and lubricating but also rich in beneficial ingredients for both your hair and scalp.
The blend features key ingredients, such as coconut oil, Jamaican black castor oil (note: this can be a heavy oil on its own, but since it’s in a formulation, chemists know how to balance its properties with other ingredients), avocado oil, grapeseed oil, and argan oil.
Additionally, it includes rosemary and peppermint essential oils that not only nourish your scalp but are known to promote healthy hair growth by stimulating the hair follicles. To top it all off, the aromatic experience is simply divine!
Natural oils and butter are effective and eco-friendly options for hair conditioning. They provide smoothness, detangle fibers, and add shine, all while being sustainable and biodegradable. We’ll explore the science behind how they work to condition your hair.
Natural oils and butters are composed of long-chain fatty acid triglycerides. They work via two pathways:23
1. They form a coating over the hair surface. (Short-term hair conditioning).
2. They penetrate deep inside the hair cortex. (More profound results and long-term positive impact).
Understanding the difference between moisturizing and sealing oils is crucial for hair care, especially for low-porosity hair that struggles with moisture retention.
Moisturizing oils have smaller molecular structures, allowing them to penetrate the hair shaft easily. These oils help to lock water molecules inside the hair, reducing moisture loss due to evaporation. Examples include oils with a high concentration of short-chain fatty acids.23
Sealing oils, on the other hand, have larger molecules. These oils form a protective layer on the hair shaft, sealing in the moisture provided by the moisturizing oils. They’re usually made up of long-chain fatty acids, making them less likely to penetrate but excellent for adding shine, reducing frizz, and protecting against environmental damage.23
In simple terms, the size of the carbon chain in the oil’s fatty acids determines its molecular size. Longer chains create larger molecules, making it harder for the oil to penetrate the hair follicle but easier to lock in moisture.
For best results with low-porosity hair, use a two-step approach: First, apply a moisturizing oil to add and lock in moisture; then, follow up with a sealing oil to form a protective barrier. This combination will help keep your hair hydrated, and healthy.
Natural oils are an amazing gift of Mother Nature for hair conditioning. Scientific studies have demonstrated certain oils can penetrate hair fiber and improve its quality.
Reigning supreme among all other options, coconut oil reigns as champion! The rate of penetration and amount of oil penetrated depend upon the chemical composition of oil, its molecular size, molecular symmetry, and polarity.
We hope this article has provided you with all the knowledge necessary to make an informed decision when selecting oils for low-porosity hair.
Remember, oils and butter should be selected based on their molecular size and the composition of fatty acids for maximum effectiveness.
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