9 Hair Products the Pros Swear By

"A lot of people are scared of oil, but it's honestly one of the best products for most hair types. I love this Kérastase Nutritive Oléo-Relax Hair Serum ($40) in particular because of its light formula that provides incredible shine and moisture. Best for thick-to-medium hair textures, all you need to do is apply one to two pumps to wet or dry hair. I use one pump every time I wash my hair and apply to hair when wet. It's great for both air-drying and blow-drying!" — Zingarino