Here's Exactly Why Your Hair Is So Greasy All the Time

"Oil production, whether it be on the scalp or the face, is mostly influenced by a person's hormones," says Dr. Francesca Fusco, a board-certified dermatologist who specializes in hair and scalp health. "If you're experiencing excessive oily skin and scalp, look for a shampoo and conditioner that is formulated for an oily scalp." Try L'Oreal Paris Elvive Extraordinary Clay Rebalancing Shampoo, $2.97, and Conditioner, $3.94, which are specifically designed to rebalance the scalp to reduce oil production while keeping ends hydrated.

If persistent oily scalp is an issue, it's best to speak to your dermatologist who can order lab tests to help identify if there is a major imbalance in your hormones, Fusco says. "Birth control pills, spironolactone or a mild diuretic may help to correct the imbalance and you will notice a decrease in oil production."