Washing your hair can sometimes seem like nothing more than a time-sucking chore. "Shampooing removes sebum or oil that normally coats the hair shaft," Dr. Brendan Camp, a dermatologist at New York’s ...

If you’re someone whose hair gets greasy a bit quicker than most, you’re not alone in contemplating whether it’s time to hop in the shower, even if it’s only been a day since your last wash. But ...