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HAIR: OILS THAT PENETRATE VS. OILS THAT SEAL THE HAIR

The use of plant oils on the hair has been common practise for centuries. Oils not only add shine but can also offer lubricating properties and tons of benefits to nourish the hair.


We classify oils on the hair in two groups: Penetrating – those oils that "feed" the hair nourishing farther into the cortex – and Sealing oils – those that "sit on top" of the hair strand, on the outside of it, making it shiny and protecting it.


Healthy hair is naturally hydrophobic, meaning, it loves water – but we don't necessarily want too much water entering the hair too quickly, as it can swell and look "poofy", then shrink it again when it's dry. Repeat this process over and over again and you can be causing hygral fatigue (essentially waterlogging it) and breakage.


We do need some water in the hair because the hair strand is made up of about 10-15% water, but the challenge is to find the perfect balance for your specific hair type.


olive oil and olives image for haircare
olive oil is often used in herbal oil infusions because it provides many benefits to hair

Different oils naturally offer different benefits to the hair. Although most oils will help repel water by sitting on top like a film, some oils are able to penetrate deeper into the hair strand than others, and as such, will offer added benefits to the hair – especially if you have dry, coarse, sun-damaged or styling-damaged hair. This doesn't mean you're going to run out and dunk a whole container of oil on your head (gosh, don't do it!) because you'll end up with a greasy head of hair that'll be tough to wash off.


Using any oil from the kitchen cupboard may also not be the best choice, because some oils can make your hair incredibly heavy and oily for your specific hair type, Plus there are proper ways of apply oil to your hair, depending on the type of hair you have and the oil you choose for it, so we'll look at that a bit later on.


putting oil on your hair can protect it from water release
Hair loves oil use much more than water. Too much water causes hygral fatigue.

Oil use on hair is not a one-size-fits-all solution, by any means. I've tried the most renowned and researched penetrating oil (coconut) on my hair and it just felt terrible after: It was super greasy, crunchy, and couldn't easily wash it out – even though I used it pre-poo, which means before washing, which is how it's best recommended. I had to use loads of shampoo to wash it out and I ended up completely drying out my hair from so many repeated washes, having to start from scratch (so frustrating!).



Have you used coconut oil on your hair and had a difficult time washing it out?
Coconut oil is wonderful for the hair – when used moderately and in combination with other oils.

Despite this bad rap, coconut oil is amazing on both hair and skin, and one of the most researched oils for use on hair. It has been proven that coconut oil can penetrate the hair, nourishing it deeper. However, using coconut oil requires a balance of ingredients that will provide its benefits in combination with other lighter oils and esters.


My best advice: Experiment with a couple of different ones and see what your hair prefers.


A note about hair porosity

If you search for "hair porosity" on Dr. Google you'll find loads of DIY tutorials and guides on how to figure out whether your hair is low or high porosity. This method basically suggests that you pull out one single hair strand and carefully place it inside a cup of water to see whether it sinks (high porosity) or floats on top (low porosity). I mean, really??


I personally don't think an adult can typically have one single type of hair porosity and have discussed this on many occasions on our live "Haircare Formulators Club" on Clubhouse. Unless you have a baby's brand-new beautifully virgin hair, your hair has likely been damaged in some form or another – whether by the drying effects of the sun, overuse of styling tools, chlorine water, colouring, hormonal changes, etc etc.


Hair is typically lower porosity closest to the scalp, where it can feel smoother as cuticles are tightly wound together, and won't need as much moisturizing because it has easier access to the scalp's production of sebum, the natural oils produced by the sebaceous glands (which are both moisturizing, protecting, anti-inflammatory and anti-fungal!). As it grows along, it's more likely to turn into higher porosity, as the sebum has a tougher time reaching aaaaall the way down to it. The longer the hair, the more you can benefit from adding some beautiful oils to your hair.



Hair is porous by nature. And everyone has different porosities on their hair, and much of it will be affected by how much damage the hair has, and on your hair type. Take the time to research which hair type you have and you will be closer to demistifying your hair needs.

A little chemistry chit-chat that you WILL FIND HELPFUL!

It would be difficult to talk about oils and hair penetration without touching on the chemistry bit, and understanding how it works and why it matters. The most important thing you must figure out is the triglyceride composition of an oil, to determine whether it will penetrate or seal the hair.

"Triglycerides are esters in all oils, and they're made up of glycerol and 3 fatty acids –