Here’s how often you should wash your hair, according to a dermatologist.

refutes this.

“Your scalp does not have a feedback mechanism that senses how much oil is sitting on top of the hair,” Dr. Docampo explains. “Oil production is controlled by hormones and genetics—not by how often you shampoo.”

Let me repeat that. Your scalp does not adjust its oil production based on your wash schedule.

The “training your hair” myth is pseudoscience. It spread because people with very dry hair who washed less often felt like their hair looked better—not because their scalp produced less oil, but because they weren’t stripping what little oil they had.

If you have an