Friday, 28 January 2011

Making washes more cleansing

In this cross section of the skin we see the different glands connected to the hair follicle.
Attached to the follicle is a sebaceous gland that produces sebum. This moisturises the hair and scalp and have an antibacterial effect. Attached to the bottom of the follicle is this little muscle: Musculus Arrector Pili. This bundle of smooth muscle fibres is attached to the deep part of the hair follicles and passes outward alongside the sebaceous glands to the papillary layer of the dermis. They act to pull the hairs erect, causing “goose bumps” or “goose flesh” in humans. This muscle is controlled by the sympathetic nervous system, meaning that we have no conscious control over it and you can't voluntarily give yourself goose bumps.
When stimulated, the Arrector Pili will contract and cause the hair to become more perpendicular to the skin surface, causing “goose bumps”. The contraction of Arrector Pili will press on the sebaceous gland and squeeze out sebum that will move out of the follicle to the surface of the skin.

No matter what wash method you use, you can make this mechanism a part of the wash. After applying the product you use to clean, you can give the scalp a cold rinse to squeeze the sebum out to the surface of the skin where you can wash it away. From what I can see, it doesn’t even need to be cold for long to get the effect. So you can turn the heat up again shortly after to wash the sebum and dirt away. The muscle will contract and press the sebum out that otherwise wouldn’t be coming out until the next day or so. This should be more cleansing because it cleans out more than just the surface sebum and keep your scalp grease free for longer so you can stretch the time between washes. So to speak, you will clean away scalp grease in advance.

This made me think of George Michael’s theory… He believes stimulating the hair strands by brushing will exercise this exact muscle to make it stronger and make it hold on to the strand for longer (= Reduce shedding) Maybe cold rinses will stimulate the muscle in the same way since it contracts and relaxes several times?
I haven’t seen any more scientific evidence behind his theory, so maybe I’m trying to see a connection that isn’t there
What is a fact though, is that temperature changes stimulates the blood flow to the skin and the supply of blood is an important factor of both skin and hair health


  1. Hm. I think since sebum is made up of a mixture of waxy substances and triglycerides and fatty acids, what we experience is the oils separating and moving down the hair strands a bit from - gravity and brushing I guess? And most surfactants are better at removing the oil than the waxy stuff.

    1. Well, that was meant for the sebum post! Anyway, thanks for your blog!