Surethik Root Penetrating Cleanser – Hair Loss Shampoo For WomenOil from the sebaceous glands, mixed with dead skin cells and the residue left from most hair products, can clog hair follicles and therefore block hair growth. Without adequate circulation, vital oxygen and nutrients cannot pass through the tiny blood vessels to the hair follicle. Without proper nutrition or the inability of those nutrients to reach the follicle due to residue and oil blockage, hair growth is stunted.