Never put a hot tool to your hair without protecting it first. Heat manipulation works by breaking down your hair’s bonds so they are easier to change and reshape. Well, this process is a lot for the strand to deal with—and it often leaves the cuticle frayed and injured.
“Most hair is made of three layers: the inner fiber called the medulla, the middle layer called the cortex, and an outer layer called the cuticle,” writes hairstylist Josh Rosebrook about damaged hair. “When hair becomes damaged, the cuticle raises, chips, becomes fragile, easily tangled, and loses moisture, luster, and the shine that’s created when the cuticle is flat and smooth.”
Now—you don’t need to avoid heat styling altogether. But you do need to be smart about it (enter the heat protectants above).
As hair expert and board-certified dermatologist Raechele Cochran Gathers, M.D., says, “I get lots of questions about heat styling, as it can cause a lot of damage. For my patients that are experiencing breakage and hair loss, I tell them to try to limit it to once weekly if possible,” she says. “For fragile hair types, daily heat styling is likely to be damaging. It’s not that these are off-limits: Just be smart about your use of your flat irons, hairdryers, or curling wands. Ultimately learning how to use these is more important than not using them altogether.”