What's inside your hair oil?

[00:00:03]Did you know oils of all types are made of acids? That always confused me because when I think of acids, I think of It turns out that the strength of an acid is determined by its molecular makeup. So, the fatty acids in oils don't burn through and destroy tissue.

[00:00:24]Instead, they nourish, heal, and protect our hair and skin. In fact, we naturally have fatty acids in our sebum and sweat.

[00:00:34]They help maintain a slightly acidic barrier called an acid mantle. So, fatty acids are super important, [music] which makes oils super important. So, in this video, we're going to take a deep dive into what fatty acids are and how they interact with our hair. First, what even is a fatty acid? Let's break down this word.

[00:00:58]Acid refers to this part right here, called the carboxyl group. And fatty refers to this chain of carbon and hydrogen [music] atoms called a hydrocarbon chain.

[00:01:12]When a carboxyl group and a hydrocarbon chain comes together, they form a fatty acid.

[00:01:21]A chain can either be short or long. It can also either be straight or what's referred to as saturated or have one kink, which is referred to as monounsaturated, or have more than one kink, which is referred to as polyunsaturated.

[00:01:40]For the most part, how coating or penetrating a fatty acid is is determined by the length of this chain.

[00:01:49]A short chain is more penetrating compared to a long chain. And how flexible it is, which aids in penetration, is determined by the shape of this chain. So, while straight or saturated chains are not flexible and tightly packed, chains with a kink are more flexible and mobile.

[00:02:09]This is more penetrating than this.

[00:02:12]This is more penetrating than this. And this is more penetrating than this.

[00:02:19]Without getting too much into the science, three fatty acid chains attached to [music] one glycerol molecule to give them structure.

[00:02:28]And this combination is what makes a triglyceride.

[00:02:32]And triglycerides [music] are what oils of all types are primarily made of.

[00:02:38]Your hair has three main layers. The cuticle is the first one. It's the outer shield that protects [music] everything inside. It's made up of tiny overlapping scales, almost like shingles on a roof.

[00:02:52]And it decides what gets in and what stays out.

[00:02:56]The cuticle layer benefits most from coating surface oils. Beneath that is the cortex or the middle layer of your hair. This is where your hair strength, elasticity, and moisture come from. So, if an oil really wants to make a difference, to nourish, repair, and strengthen, >> [music] >> it has to make its way past the cuticle and reach this layer. The third layer is [music] the medulla, which is the innermost part of your hair shaft. Not all hair strands have a medulla, especially fine or thin ones. But when it's present, [music] it forms the core of the strand. Some oils are even penetrating enough to reach this deepest layer.

[00:03:41]To give you a better visual of how fatty acids interact with natural hair, I categorize them [music] into four zones.

[00:03:51]Zone one contains what I like to call the surface guardians.

[00:03:55]These fatty acids can't slip between the tight layers of your cuticles.

[00:04:01]Instead, they stay right on top of your hair.

[00:04:03]>> [music] >> Their job is to create a protective coat that helps your cuticles hold onto moisture and smooth over areas that may be slightly raised or worn. So, yes, surface oils matter a lot and they definitely have their role.

[00:04:19]The standout fatty acid in this zone is called ricinoleic acid. It has an 18-carbon chain, which makes it long.

[00:04:28]And it's monounsaturated, [music] meaning there's one kink in the chain.

[00:04:34]So, it has some flexibility, but it's [music] long, so it's not that penetrating. What makes ricinoleic acid special is that it has both a typical carboxyl group that I spoke about earlier and an additional hydroxyl group.

[00:04:51]That extra molecule gives it even [music] more weight and thickness.

[00:04:56]So, even though it has flexibility, that extra hydroxyl group makes ricinoleic acid extra thick, sticky, and heavy.

[00:05:07]A great example of an oil with tons of ricinoleic acid is castor oil.

[00:05:15]Zone two is what I describe as the cuticle visitors. These fatty acids mostly stay near the surface.

[00:05:23]>> [music] >> They slip into the outer layers of your cuticle just enough to make a difference, typically moving about 10 to 30% into the outer region before stopping.

[00:05:34]Because they don't travel far, they sit close to the surface and contribute to a soft, smooth feel. They never reach the cortex. [music] Once they settle into that shallow space, the rest of the molecule remains on the surface, adding a light coating to your hair.

[00:05:53]This is why zone two oils can be described as hybrids. They offer a touch of internal conditioning while also lightly coating the outside [music] and boosting shine.

[00:06:05]Two key fatty acids in this zone are palmitic acid and stearic [music] acid.

[00:06:12]Palmitic acid has a 16-carbon chain and stearic acid has 18.

[00:06:18]Both are saturated, which means their chains are long, straight, and tightly packed. This structure makes them sturdy and heavy, but not as heavy as castor oil's ricinoleic acid. So, rather than just coating the surface, they anchor themselves in the outer cuticle and leave behind a light waxy layer.

[00:06:43]These fatty acids are what gives butters like shea butter and cocoa butter their creamy, buttery feel. They don't penetrate deeply, but they add softness.

[00:06:56]They reduce friction and make your hair feel well conditioned on the surface.

[00:07:01]Now, moving deeper into your hair strand, we reach zone three, the cortex travelers.

[00:07:09]These fatty acids go further than the cuticle visitors, but don't make it all the way through your hair strand. Most of them are able to move past [music] a good portion of your cuticles, about 50 to 70% before stopping.

[00:07:25]While some will continue to reach roughly 20 to 50% of your cortex, they don't reach the deepest parts of your hair, but they still deliver meaningful conditioning and flexibility from within.

[00:07:39]I like to think of them as mid-level conditioners because they work both at the surface and inside your hair.

[00:07:47]The first major fatty acid in this zone is oleic acid, which has a 18-carbon chain and is monounsaturated.

[00:07:58]So, even though it's long, that one [music] kink helps with its mobility.

[00:08:03]Because of that, oleic acid [music] is able to wiggle its way in and settle in the middle cortex layer, as opposed to reaching the very core.

[00:08:13]Oils rich in oleic acid like olive, avocado, and almond oil gives your hair internal softness and hydration without making it feel heavy.

[00:08:26]Next is linoleic acid, which has an 18-carbon chain and is polyunsaturated.

[00:08:34]So, it has two kinks.

[00:08:36]This additional kink makes it more flexible and mobile. So, linoleic acid also slips into the cuticle and reaches parts of your cortex.

[00:08:47]It helps rebuild your lipid barrier, support elasticity, and keeps your hair hydrated and resilient. You'll see linoleic acid in oils like sunflower, grapeseed, and safflower. And even though these oils often get labeled as sealing oils, the presence of linoleic acid means they do have some penetrating abilities.

[00:09:12]Now that we've covered the mid-level conditioners in zone three, we can finally get to the deepest layer of all, zone four.

[00:09:22]This is where the real heavy lifters show up.

[00:09:26]Zone four is what I refer to as the deep penetrators.

[00:09:30]These fatty acids may be tiny, but their ability to travel through your hair strands is remarkable.

[00:09:38]They can slip through about 70 to 90% of your cuticle, almost the entire layer, and continue into the cortex, reaching roughly 40 to 70% of the inner region where your hair gets its strength and elasticity.

[00:09:53]Some of them can even reach the medulla, the central core of your hair strand.

[00:09:58]When you use oils rich in zone four fatty acids, you're not just coating your hair. You're reinforcing it from the inside out. Think of these as your internal repair crew.

[00:10:12]One of the most important fatty acids in this zone is lauric acid. It's a saturated fatty acid with a 12-carbon chain. So, its chain is short and straight.

[00:10:25]That compact structure is what allows it to glide through your cuticles so easily.

[00:10:31]Studies show that oils rich in lauric acid, like coconut oil, can reach your cortex and help reduce protein loss, like a shield from within.

[00:10:42]That's a big reason why coconut oil has earned its reputation for boosting internal strength.

[00:10:49]And why tons of naturals use it as a pre-poo.

[00:11:01]Lauric acid also does more than simply enter your hair.

[00:11:06]Once inside, it binds to the keratin, the main protein your hair strands are made of, helping protect it from being washed or worn out. So, in other words, it slows down the natural wearing and tearing of your hair.

[00:11:21]Lauric acid is not the only deep penetrator, though.

[00:11:25]Myristic acid, which has a 14-carbon chain, it's a little bigger, but still small enough to move deeply into your hair strands.

[00:11:34]And then [music] there's capric acid, with just a 10-carbon chain, so even smaller than lauric acid. It also slips into your hair shaft really easily.

[00:11:45]All three of these fatty acids are in coconut oil and babassu oil, working together to provide deep internal nourishment and long-lasting strength.

[00:11:56]Individual fatty acids are pretty straightforward. They're easy to isolate and observe how each interacts with your hair.

[00:12:05]Now, the reality is that oils have a combination of different fatty acids.

[00:12:11]And in addition to that, things get a little more complicated when you mix different oils together.

[00:12:18]So, I'm going to be working on a video that goes over the complete fatty acid profiles of popular oils like castor, coconut, avocado, jojoba, just to name a few.

[00:12:33]And I'm going to give you some pointers on oil and butter combinations to enhance their benefits.

[00:12:39]Because to find an oil combination that your hair loves is to find a good thing.

[00:12:46]As always, thanks for watching. See you in the next video.