Kérastase Genesis Defence Thermique Blow Dry Primer
"I rarely blow dry my hair because I'm afraid of damage. The Kérastase Genesis Defence Thermique Blow Dry Primer ($37) helps with those fears by protecting against heat damage, preventing split ends, and detangling so you don't experience any breakage when styling. It leaves my hair silky-smooth and reduces frizz — something I have a lot of trouble with whenever I heat style my hair." — JH