A shampoo ideal for oily scalp removes just the right amount of dirt and oil without drying it out. One of the more important ingredients needed in a shampoo for oily scalps is an astringent, which works to remove excess oil but does not dry out the scalp.
Equally important is that the shampoo have a pH greater than 6.7, which inhibits oil production. Shampoos labeled clarifying, volumizing or strengthening have this high pH and work well to clean both the hair and scalp. Essential oils, such as lemongrass, peppermint, tea tree and cypress, can also be great additions in a shampoo aimed to rectify an oily scalp. The shampoo should not contain any additional conditioners (terms used can be hydrating or moisturizing), as they only add more oil into the hair. Vitamin C and B can also be great when in a shampoo, and even better when included in one's diet. Keeping brushing at a minimum, regular shampooing and a proper diet are perfect companions to the ideal shampoo.
The skin and scalp produce oil (sebum) to lubricate the hair. When there is too much sebum produced, the hair appears greasy, and dandruff can develop. When sebum is held at bay, the hair looks smooth, conditioned and healthy.