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

Whether you hit the gym a lot, live in a hot climate or are simply prone to sweating, this can certainly lead to an oily, itchy scalp.

"Excessive sweating on the scalp mixes with oil, creating a kind of oil slick on the scalp and hair," Fusco says. "Botox injections to selective areas of the scalp may reduce sweating and therefore make hair look less oily."

If you're not digging the Botox idea, a good pro tip is to spray dry shampoo on your hair before working out to help absorb sweat through all those burpees. The same rule applies any time you think you're going to sweat—apply before the sweat-fest. For those with itchy scalps, you can get some extra relief via a leave-in scalp treatment, such as Oribe's Serene Scalp Soothing Leave-On Treatment, $48, or Briogeo's Scalp Revival Charcoal + Tea Tree Scalp Treatment, $32.