When selecting the perfect of-the-moment style for you (A rockabilly mullet, perhaps? A blunt bob? A mermaid-worthy mane?), a universal truth guides us all: damaged hair is a bummer. Even the coolest cut and color lacks the impact of well-tended lengths. Common telltale signs of damage include split ends, a lack of moisture, and overall dullness—but identifying a problem is the first step to solving it, and in this case, maximizing aesthetic shine.
Shab Caspara, New York City-based trichologist and founder of hair-care platform Leona, says that a poor hair care regimen can lead to weaker, frizzier, and more brittle strands over time. “The common causes of hair damage include mechanical damage (brushing, hair ties, extensions, and overall friction), chemical damage (overly bleached or processed hair), and thermal damage (flat and curling irons),” she details. But the culprits aren't limited to styling alone. “The causes of hair fiber damage often have internal causes layered with the mechanical external causes,” explains New York City trichologist Bridgette Hill, citing prescription medicine intake, diet, vitamin and mineral deficiencies, age, hormones, products, and styling habits as causes of damage.