Is coconut oil really the only oil to penetrate the hair shaft?

[GoddesJourney]

I have read this many times and I wonder if it is one of those things where not many oils were tested. I actually have no idea where the information even came from in the first place. It seems to be just something that "everyone knows" but I've never seen where or how it started.

Anyway, my skin and hair both seem to love macadamia oil more than any other oil, avocado oil being number two. I tried adding macadamia oil to a conditioner that I tried and did not find moisturizing. A CO wash with said conditioner seems to leave my hair just slightly oiled until the next day when I shampoo and condition with another set of products. However, once my hair is clean, it feels...heavy? Even when it is dry it still behaves like it is just slightly damp, but not on the surface.

I have tried this with a warm shower and also with a shower that starts warm and ends cold. The results are the same. My hair feels this way for a couple of days and then seems to more or less go back to normal.

Coconut oil seems to give me the crunchies.

Your thoughts? How would one even try to prove whether the oil does or does not penetrate the hair shaft?

[Ylva]

This chart is quite useful.

[MusicalSpoons]

You may find this interesting https://science-yhairblog.blogspot.c...coat-hair.html Edit: Ylva​ beat me to it while I was investigating

And https://www.thenaturalhavenbloom.com/search/label/Oils if you fancy more reading, though I don't know if any of them actually answer your question

[Belgrade Beauty]

TBH I think it depends on your hair and I don't have any good advice that someone else here didn't give already. It worked for me for about a month and ever since its made my ends crunchy and dry so I stopped using it. I don't care if it penetrates the shaft or not, I just want my hair to be soft and silky afterwards. :cryinside: Olive oil does that for me. For now.

[jane_marie]

This chart is quite useful.

Oh that's interesting. Perhaps the shorter lipid chains are the reason that hemp seed oil works so well on my hair.

[Firefox7275]

A CO wash with said conditioner seems to leave my hair just slightly oiled until the next day when I shampoo and condition with another set of products. However, once my hair is clean, it feels...heavy? Even when it is dry it still behaves like it is just slightly damp, but not on the surface.

I have tried this with a warm shower and also with a shower that starts warm and ends cold. The results are the same. My hair feels this way for a couple of days and then seems to more or less go back to normal.

Coconut oil seems to give me the crunchies.

Your thoughts? How would one even try to prove whether the oil does or does not penetrate the hair shaft?

The roots should be the healthiest, least porous hair on our heads, so oils will not penetrate as well as they might on older, 'weathered' ends or colour-treated lengths.

Even with porous hair, it is easy to overdo penetrating oil treatments. Applying too much or too frequently say. If the hair is coated with residual oil, rinse-off conditioners may be ineffective.

[Laurab]

I've honestly read so much conflicting information on it, idek.
I've read that coconut oil is the only one, I've read that coconut, olive, and avocado will penetrate but not others, I've read that any oil with small particles like grapeseed will, it's very confusing. I'll also say that for a lot of oils, when you try and research hair benefits you'll wind up at a website that sells that oil, so of course they're going to exagerrate claims.
In general I think there's just a lack of actual scientific research on it.
I love that blog post linked from Science-y, it's a great idea to try and connect what we do know for certain, since there's holes in the research.

But all in all, I agree that it's less about what's shown to penetrate and more about trial and error for what works with our hair.

[AutobotsAttack]

There’s actually a very intricate meaning to the word “penetrate”. It becomes confusing because most researchers who actually take the time to look at how hair behaves under a microscope, go into vast detail about this, but stuff gets lost in translation along the way, concerning who reads it, and who relays the info they’ve found.

There’s what’s known as cuticle-cuticle bonds, concerning the outer layer of hair structure, and the cortex-cortex bonds concerning the inner layers of hair.the cuticle bonds are mostly covalently bonded, while the cortex bonds are non-covalently bonded. Thing with that is, the cuticle itself, along with certain parts that are membranous in nature, as well as the varying natural lipids it possesses, are mostly non-polar. Hence why, for certain hair types, only so much water will be let in, and also plays a role in porosity.

But, going back to Chemistry class, and digging up certain solubility rules, covalent solubility obeys the “like dissolves like” rule. Meaning if a compound is polar it will typically dissolve or in our case of product usage, “penetrate” with another polar substance. Same thing with non-polar compounds. They will dissolve in other non-polar compounds. So I’m essence, concerning other oils, and butters, the majority of them actually penetrate to some degree into the hair shaft. It’s not just coconut oil. Vegetable oil will penetrate to some degree. Cocoa Butter, Shea Butter, Mango butter, regular cooking butter, grape seed oil, olive oil, almond oil, jojoba oil, etc.

Same thing applies with other products too. Not just oil. Conditioners and leave-in products will follow those same rules of solubility depending on its formulation, and how much of whatever certain ingredient the manufacturer uses.

Of course there’s room for variation, and the state of the individual’s hair can come into play a lot. High porosity hair like mine is lacking a lot in the natural lipid bilayer that’s present within, and on the hair shaft. Same also goes for the ends of individuals with very long hair. Through regular wear and tear, again, the natural weathering of the cuticle weakens these typical cuticle-cuticle bonds present within the hair, allowing for usually greater absorption, or in science terms, bonding of certain compounds with the hair.

[AutobotsAttack]

But there’s also the phenomena of saturation that plays a role too. There’s under-saturation, saturation, and super-saturation that ties in concerning solubility. Super saturated mixtures, will kind of destabilize. So translate that over in hair terms, super-saturation can often feel like the product is just sitting on the hair. That’s not to say the oil has just already penetrated the hair. For example if you’ve got an individual with very low porosity type hair, they’ve already got adequate amounts of the natural lipid bilayer that’s present within and on their hair, but they’re trying to add an outside oil to their hair. Following the law of saturation, they’re dealing with an instance of super-saturation, by way of their natural oils, and additional oil being added that’s causing a destabilization in the form of the outside oil just sitting on top of their hair.


Now take an individual with high porosity type hair. They’re lacking in the natural lipid bilayer found on and within the hair. So they’ve got some room to work with concerning adding additional oils to their hair. They can reach a level of saturation that would feel nice when they touch their hair. Ergo the feeling of the hair being “moisturized”. Say they aren’t adding enough oil. Under-saturation. Their hair may still feel very dry, or feel like the oil is still sitting on top of their hair. It may very well be so, in which it could be a combination of inadequate saturation, but also an issue with solubility, type of product being used, or the cuticles being so roughed up, that it feels like nothing is penetrating, when in essence is just the cuticle-cuticle bonds probably being so broken and roughed up that other wise “normal” amounts of oils or product just doesn’t seem to feel or work right.


There’s a lot of things that can come into play with oils, and how individuals interpret how they perceive the oils to be interacting with their hair, but in general, most oils “penetrate” concerning the laws of chemistry. They may not feel like they do to certain individuals, and there’s plenty of articles that are often misleading, but by way of deduction, and brushing up on a bit chemistry, you start to see a bit of a pattern. I’ve completed two Chemistry degrees, so stuff like this is mostly what I consume my time thinking about lol.

Apologies if what I said is confusing. I can go further into detail if need be.

[squirrrel]

That’s interesting. Thank you for taking the time to explain.