Basically the most common causes of oily hair go to environmental factor and hormonal imbalance…

In order to get rid of oily hair that is caused by environmental factor, you need to shampoo your hair as a given amount of shampoo can remove so much oil… it is better to apply the shampoo when your hair is wet and massage the your scalp for at lest five minutes, then rinse and repeat the process…

However, if you feel that your hair is caused by hormonal imbalance, you need to consult with your doctor to determine if there is a medical cause…