Kerastase is the luxe haircare brand famous for straightening the strands of Jennifer Anniston, Blake Lively, and Rachel Weisz. Though it only hit the high-end hair salon shelves in 1999, Kerastase has actually been around since the mid-’60s — but only in France. The name Kerastase comes from the word “keratin,” which is the main structural element in hair and nails. In fact, Kerastase is also described as a keratin treatment. (And that’s your science lesson for the day.)

Click on the video to hear the correct pronunciation of the beauty product.