Part 2: The necessity of oils

So in part 1, I explored research on why water is pretty much on crutches when used on its own as a moisturiser. In this part, I will now discuss one of three ways to make water more effective as a moisturiser. As suggested by many of you already in the first part, one of the most researched topics is the moisturizing effect of oils in hair. I realized that I had gone all scientific in my diagrams but since I am too lazy to revise I will just clarify here oil=lipid=fat (they are all the same thing really).

Now I will start by introducing a 'new' concept. It is only new because I haven't talked about it before. However since I'm now getting questions on ceramides, I think I have to introduce it.

There are two main types of oil in the hair. An internal oil which acts as a glue to stick the cuticle cells to each other. This oil is very hard to remove in normal circumstances (i.e washing or conditioning). However treating hair with an alkaline substance could affect it ( colour treating, bleaching or relaxing). The second oil is sebum which many of us will know about. It is an external oil which coats the outside of hair and is pretty easy to remove with shampoo.

Oils in hair and skin have a key role in maintaining moisture. Hair is happy to take up water but it is equally happy to give it away. This is where oils come in and they perform in two main ways.

First they slow down water loss from the hair. Simply put they form a barrier preventing the water from escaping as fast. Water retained in hair = moisture success.
The second effect of water is to reduce the impact of the surrounding environment. Oil repels water meaning water is much less likely to sit on the surface of the hair. This action slows down water uptake but do keep in mind that the hair WILL still take up water. The oil again just serves as a barrier which manages the exchange of water and research shows hair with oil does a much better job than hair with no oil.

I don't want to make this an overly long post so perhaps over the course of the year I'll do more detailed posts on the types of oil to look out for and because you asked....... something more on ceramides.

If you are curious, next up is the very confusing topic of humectants and specifically glycerin - it definitely could help water along

J Cosmet Sci. 2009 Jan-Feb;60(1):31-44
J Cosmet Sci. 2007 Mar-Apr;58(2):135-45.
J Investig Dermatol Symp Proc 10:234 –237, 2005
Lipids. 1988 Sep;23(9):878-81
Int J Cosmet Sci. 2009 Feb;31(1):21-5
Biochimica et Biophysica Act. 2001, 1547(2, 268-274
J Soc Cosmet Chem. 1989: 309-320


  1. Wow, thanks for getting ready to answer my question. This made my day! ^-^

  2. Hmmm... i'm lost lol! I understood oils can seal moisture provided by water. But it can't moisturize hair... so what about coconut oil? i've heard it has moisturizing properties...

  3. Ok, so basically water alone is not enough. but if hair is sealed with an oil, water retention is increased?

  4. Thank you so much for sharing. This answers a lot of questions and breaks down why sealing moisture in with oil is so important.

  5. @Marie Grace - I wouldn't really use the term 'seal' because it sort of implies that water cannot get in once an oil is applied but in reality water can still get in. However, the general concept that oil can help keep the moisture in is true. I'll get onto coconut oil in a later post too Marie. It does penetrate hair just as water does.

    @Natural hair selection - Yes and also water uptake from the environment is slower hence the the moisture level is maintained.

    @Addy and Sunshyne- Thanks for commenting and you are very welcome :)

  6. i love your blog. what kind of oils can effectively coat the cuticle to form a barrier to maintain that moisture balance all day?

  7. JC, you are talking about water taken from the air right?

    I wonder if, after the first application of water and oil and after the water has traveled from inside the hair shaft, do we just reapply water to the hair for the oil to keep it in longer or do we have to put oil on again ?

  8. @shae - I'll put up a post shortly about combining glycerin and jojoba oil. It was shown to be effective for 24hours. However, artificial sebum used in research actually contains a large combination of oils. I'll put that up too soon.

    @Kadiane - Yes water from the environment around the hair. If you already have oil on the hair you can just reapply water, it will get into the hair. However if you consider all the rubbing (handling the hair, sleeping, perhaps wrapping the hair in a scarf etc) it is likely that the oil layer decreases. Therefore it is a question of balance and using your own judgement, for example, if the hair feels quite oily, then reapplying some water may be enough. But if it doesn't then adding some oil may be necessary.

  9. This was really informative. Water was never enough for my hair if I did not supplement it with anything else. I also noticed just oil isn't enough as a moisturizer either. So what I started doing recently is after I dampen my hair, i put suave conditioner in & then coat it with softee brand of castor oil, which also has coconut & several other oils in it & it works!!! It really keeps my 4b hair moisturized throughout the day.

  10. Hey JC...GREAT post! Question: if coconut oil fully penetrates the shaft then is it appropriate to use it as a sealant??

  11. This was another great post thank you so much!!I loved both Kadiane and Nneka questions!! I'll be looking for your response to nneka's question too :). So many women use so many oils on their hair. I would like to stick with one or two oils. I read in an earlier post were you recommended using coconut oil and water together...I wanted to ask if you if you thought using coconut oil(or another moisturizing oil) and water on natural hair is all you need or should coconut oil be mixed with another oil so that it can be more beneficial??

  12. So on average how long does it take for water to travel to or from the shaft? Or how long can pass before adding the oil to 'seal' is pointless because the hair shaft has already lost the water again? A few minutes? Seconds?

    It just seems a bit odd to add oil when the hair is still wet and possibly not even had the chance to reach the shaft, and possibly creating a barrier that may even stop (or at least slow) the water penetration.


  13. I have a question about oils as a seal. I have a combo 3C/4A hair type. Very dense, very low porosity. I use black castor oil and coconut oil as a sealant after I have washed, and conditioned my hair. I apply the oils to my damp hair, then braid it. After my hair drys, usually 10 hours later, my hair is oily, and still out of control. Could it possibly be the combo of the two oils that is cause the oilyness? This site is awesome btw, you are really good at explaining things very clearly :)


Post a Comment

I love comments! All comments are moderated so they will only appear on the blog once I approve them.

Popular Posts