Editor’s Note: Lab Notes is an ongoing series where we shed a scientific light on common hair questions, myths, and problems. Read our latest post on how to avoid bubble hair.
Where can you find the latest darling of the beauty industry? In your kitchen cabinet.
Coconut oil, extracted from the “meat” of coconuts, has recently been touted by fans as a hair moisturizer, defrizzer and styling gel, not to mention a body lotion, eye cream, makeup remover, teeth whitener and mouthwash (just to name a few).
The broad range of benefits almost sounds too good to be true — and some of them might be, as there isn’t solid research supporting every proposed use of coconut oil. But when it comes to what the allnatural oil can do for your locks, the evidence is solid.
So should you toss out your can’tlivewithout hair regimen and trust coconut oil as a magic cureall? The answer comes to down to science (and a bit of history):
What is it?
While coconut oil only recently came into the mainstream spotlight, it has been used for centuries by women in tropical regions to maintain hair with documented beneficial results: prevalent healthy hair and fewer infections. Why are we so behind the curve? Coconut oil is one of the richest sources of saturated fat with 90 percent of its fatty acids being saturated — and for the past few decades, health researchers saw saturated fat as a death wish for heart disease. This popular belief has since been disproved, and we’ve started to learn more about the unique makeup and potential benefits of coconut oil.
As it turns out, the level (and specific type) of saturated fat in coconut oil is what makes the product so great for your hair.
The most common saturated fatty acid in coconut oil is “lauric acid,” a medium-chain fatty acid with a 12-carbon atom chain (bear with us, the number does matter). When these medium-chain fatty acids react with glycerol, they form a medium-chain triglyceride (a triglyceride with only 6-12 carbon atoms). This abundance of medium-chain triglycerides (as opposed to the long-chain triglycerides in many other oils) is what truly differentiates coconut oil from other oils and products, as it’s able to penetrate the hair shaft thanks to its low molecular weight and straight linear chain.
How does it work?
Does it matter if coconut oil can soak into the hair shaft?
It actually does. You’ve heard us say before that hair is most vulnerable when wet. That’s because the middle layer of your hair shaft (the cortex) swells when filled with water, which forces apart the cells on the protective outer layer (the cuticle) and makes them susceptible to breakage. Healthy, strong hair is naturally water-repellent and shouldn’t swell. But if your hair is damaged or dehydrated at all — which regularly occurs from heat styling, hair products, sun exposure or even your diet — water can easily get inside and create more harm.
Nearly any oil can help your hair repel water, but penetrating oils like coconut oil go to the source by adding a hydrophobic (water-repellent) component to the cortex itself — preventing swelling and lifted cuticle layers. The end result? A significant reduction in protein loss from grooming and styling hair that will lead to silky, smooth, shiny locks.
When should I use it?
Depending on your hair type, you’ll likely want to test out different techniques and amounts of coconut oil. Most methods recommend melting a quarter-size dollop of coconut oil by running it under warm water in a container or by rubbing it between your palms.
One of the most common and effective uses of coconut oil is as a pre-shampoo conditioning mask. It may seem counterintuitive to condition your hair before you wash it, but remember that you want the oil to soak into your hair shaft. Let the oil soak in for 2 or more hours (the longer you leave it in, the deeper it will condition). Your hair should still feel very soft after you wash it, so you won’t likely need a second round of conditioner — but if you do, coconut oil also works as a rinse-out conditioner after shampooing.
You can also try coconut oil is as a leave-in conditioner, detangler or styling gel. After a shower, gently massage the oil into your hair starting at the end of your strands (avoid your scalp unless you have dry skin or dandruff). You should notice fewer fly-aways and pesky frizz for the rest of the day. If you have curls or waves, they will be more defined.
No matter what method you test with coconut oil, we’re confident your locks will thank you. (Not to mention your budget — one writer found that switching to coconut oil could save her $447 a month.) Plus, since coconut oil is free of the harmful chemicals and artificial ingredients found in many hair products, the benefit comes without sacrifice.
For a deeper dive into the benefits of coconut oil for hair, check out these consecutive studies in the Journal of Cosmetic Science: “Effect of coconut oil on prevention of hair damage” and “Effect of mineral oil, sunflower oil, and coconut oil on prevention of hair damage.”