Water Works

Proper hydration is the key to healthier, more manageable hair-and it doesn't entail a dramatic overhaul. It starts with a little knowledge and ends with a few moisturizing micro-adjustments to your routine.

- Erica Metzger

News flash: There’s a method cosmetic chemists and beauty scientists regularly use to solve dryness, frizz, and damage—and you can use it at home. Knowing your hair’s porosity (something that’s frequently discussed within the textured-hair community on message boards and subreddits) can reveal a lot about your hair, like why you may be prone to flyaways or what the best products are for the style you want.

Essentially, porosity describes your hair’s relationship to water, and it can range from low to high. “How much water your hair holds and how long it takes for it to dry is the simplest way to understand porosity,” says Felicia Leatherwood, a celebrity stylist who works with Issa Rae and Ava DuVernay. Read on for a professional strand plan.

Why This Matters

 How can one head of hair appear dehydrated and crispy after sucking up half a jar of conditioner, while a different set of strands takes a full day to dry? Porosity explains it all. It’s determined by the position (and condition) of your hair strand’s protective exterior, called the cuticle layer. “Cuticles are meant to overlap to keep the moisture in and protect the inner cortex from heat and the environment,” says Corey L. Hartman, MD, a dermatologist in Birmingham, Alabama.