OK, but here’s the thing: As much as you can baby your locks with masks, leave-ins, and serums, you cannot fully heal damaged hair. 

“Hair is not like skin; it does not heal,” says Warren. “When the skin is injured, the body’s natural healing process kicks in. The damaged cells are replaced by new cells, and the wound gradually closes. The healing process can take time, but eventually, the skin can regenerate and return to its previous state.” 

Your hair cells, on the other hand, are already dead—they are not capable of regenerating or repairing once they grow out of your head. So while you might see products that claim to heal damaged hair, what they’re really doing is improving the appearance of the hair, not reversing damage itself. 

So if you really want to save your brittle, damaged locks, the best thing you can do is shear off the ends and start anew. “If hair is damaged, it must be replaced by new hair growth,” Warren adds. “This process can take time, and the damaged hair will remain damaged until it is cut or falls out.” All that to say: Time for a trim!