Hair OilsQ: What is the proper name for the oils we have in our hair that make it greasy or oily? Doesn't dry hair have as much oil?
A: The oily substance produced by the skin and scalp is called sebum. It is intended to act as a lubricant and protector for the skin and hair. When the sebum is allowed to build up on the scalp and hair (or if the skin's production of sebum is hyperactive) then the hair may appear oily.
The sebum is intended to be spread along the length of the hair shaft. This usually occurs through brushing the hair with a natural bristle brush. Yet when the sebum-production is over-active, then you may need to use an oil-control shampoo or adjust your hair-washing regimen.
While overproduction of sebum is a common cause of oily hair, dry hair isn't necessarily a sign of low sebum production. Dry hair typically refers to lack of moisture in the hair. This is generally caused by the hair's cuticle layer being raised or damaged, either from chemical services, or styling damage caused by excessive heat or rough treatment.
When the cuticle is raised, moisture passes easily into and out of the hair shaft. So while the hair will seem to soak up conditioners and moisturizers readily, the benefit of such products tends to be lost as the moisture simply evaporates unless treatment is used which helps smooth and seal the cuticle once more.
How to brush hair to reduce the oil production
Causes of oily hair
Oily hair shampoo
Home remedies for oily hair and for dry hair