• If you are pre-disposed to dry hair through your gene make-up, there are some things you can do to help add elasticity and strengthen.  Weakness comes from the break-down in the follicle molecular structure.  Lack of membrane fluids allows bonds to break easier resulting it what appears to be brittleness.
• Heat and chemical treatments deplete hair of moisture content, again, breaking down and destroying molecular bonds that allow for elasticity.  Styling appliances can, literally, steam or dry, water out of the follicle shaft.  Replacing depleted moisture can be done with conditioners or shampoos developed to infuse moisture into the cells.
• Lack of moisture can be the result of poor sebum or hair oils.  Oils are secreted from root pore and help to protect the hair's structure.  Oils also protect internal functions.  If oil production is low, you may see that the causes of dry brittle hair lie in improving moisture content to the hair.

Using hair care products developed to add moisture and protection will help address the causes of dry brittle hair and will improve control.