Chemist point of view- back to the basic and several questions

**Anabell** · February 13th, 2016, 04:48 AM

Hey there!
I joined to LHC several years ago so I read a lot about hair care in the past few years. I also a chemist. I have a background both at chemistry and biology so I have general clue about hair structure and how hair products supposed to work.
Now, I've been thinking about several things I take for granted and also I want to ask the chemist in this forum:
Pre-poo treatment- whet exactly the purpose? I explain: basically we put some oil on dry hair before the wash. But if the hair is dry there no moisturize locked in within the process. The oil only acts like a barrier between the water in the air and the water inside the hair shaft. So I guess it just to prevent the shampoo wash the length? Isn't it will be better to spray some water on the hair before applying the oil to also lock in some moisture? So I tried it. The immediate result was weird. In the outside it feels really silky and smooth but the hair was locked in some kind of waves or locks and if I wanted just let my hand through the hair it was difficult. Now my hair is drying after wash so I will see the final results in a couple of hours.
So did anyone tried it? What was your result? What do you think about this method?
In generally speaking, what the advantages of just put oil in a dry hair? Does it gives something else other than a water barrier?

Another question that came to my mind: Humectants- how they work? Salts for example bad for hair because they absorb water both from the outside environment and from the hair itself. Humectants are considered good for hair because they draw water into the hair (for example aloe vera, honey). But how does it works? How it can draw water just in one direction from environment to the hair and don't take water from the hair itself?

**Nique1202** · February 13th, 2016, 04:51 AM

I don't know about the pre-wash oiling, but I can say for humectants, it depends on how dry or humid the environment is. If you live in a very humid area, then humectants will (or are supposed to) draw moisture from the environment into your hair. If you live in a very dry area, humectants will (or should) draw moisture out of your hair. That's why it's always important to consider your climate when you decide whether to use products with humectants or not.

**pailin** · February 13th, 2016, 05:51 AM

Nique is right about the humectants. And some of our members have commented on this- trying a new conditioner with aloe, for example, while on vacation, and loving it. Then going home to a dry climate and finding it terrible.
Regarding prewash oil, there is evidencethat coconut oil penetrates the hair shaft, so for it, prewash oiling is believed to help by reducing the amount of water taken up by the hairshaft during washing, and thereby reducing stress due to water, since water makes the hair swell. See this article: http://www.ncbi.nlm.nih.gov/pubmed
For most other oils, presumably preshampoo oiling does, as you say, merely reduce hair contact with shampoo.

ETA- regarding humectants, I'm not certain whose comments I'm remembering. Possibly Quasiquixotic.

**Anabell** · February 13th, 2016, 09:43 AM

Thank you both for the informative responses. Totally forgot about the penetrating thing of coconut oil. So basically you can get two totally different treatment out of one product- a moisture treatment if you seal water in or a protein treatment (coconut oil has some protein in it) when use on dry hair. And of course we have this untrusting relationship of hair with water. At one hand hair can't do without some water and at the other hand too much water cause a hair shaft swallow and do some damage.
And humectants basically acts as a water gate and accelerate water transfer from high concentration to low concentration. This is confuse me because I know they are good (SMT treatment- some members here get very pleasant results with it) but I can't get how. Because what's the point using them when you have humid air anyway? You need the moisture in winter when you have dry air and so you hair and skin dry out. Anyway, just sharing my thoughts.

**lapushka** · February 13th, 2016, 09:52 AM

Originally Posted by Anabell

Thank you both for the informative responses. Totally forgot about the penetrating thing of coconut oil. So basically you can get two totally different treatment out of one product- a moisture treatment if you seal water in or a protein treatment (coconut oil has some protein in it) when use on dry hair. And of course we have this untrusting relationship of hair with water. At one hand hair can't do without some water and at the other hand too much water cause a hair shaft swallow and do some damage.

Nope, coconut oil does *not* have protein. It keeps the protein in the hair, though.

**MsPharaohMoan** · February 13th, 2016, 10:09 AM

Thank you Lapushka. Common misconception.

Pre poo treatments prevent hydral fatigue - hair swells with water and cuticles open. Doing this too often will cause cuticles to not be so efficient at closing (or something along those lines).

**hanne jensen** · February 13th, 2016, 10:12 AM

Originally Posted by MsPharaohMoan

Thank you Lapushka. Common misconception.

Pre poo treatments prevent hydral fatigue - hair swells with water and cuticles open. Doing this too often will cause cuticles to not be so efficient at closing (or something along those lines).

I didn't know this, thanks for that information. Can I use coconut oil as a pre poo treatment? I have around 200 grams of the stuff that needs to get used up.

**lapushka** · February 13th, 2016, 10:30 AM

Originally Posted by hanne jensen

Can I use coconut oil as a pre poo treatment? I have around 200 grams of the stuff that needs to get used up.

I don't see why not.

I wouldn't use too too much of it, though, just enough to coat your hair, otherwise you'll be washing it out twice (or even more depending on how much you used) and that kind of defeats the purpose.

**Entangled** · February 13th, 2016, 10:50 AM

Originally Posted by lapushka

I don't see why not.

I wouldn't use too too much of it, though, just enough to coat your hair, otherwise you'll be washing it out twice (or even more depending on how much you used) and that kind of defeats the purpose.

I use coconut oil as a pre-poo. I don't know how this works for other people, but I use a lot--I put it in until it's very stringy and looks wet, but it always comes out with just conditioner. I've never used shampoo to get it out. Conditioner works great to get out oil, but not sebum for me.

**Silverbrumby** · February 13th, 2016, 10:59 AM

Originally Posted by MsPharaohMoan

Thank you Lapushka. Common misconception.

Pre poo treatments prevent hydral fatigue - hair swells with water and cuticles open. Doing this too often will cause cuticles to not be so efficient at closing (or something along those lines).

Very interesting. My hair definitely swells with washing so pre oiling will I'm guessing reduce the swell shrink cycle of my hair there preserving the out cuticle which In parts shine and improves hair shaft strength.

Thinking out loud.