Kerastase is a company owned by L'Oreal. The products are mostly sold in fine salons but drugstore.com also carries them (although they cannot guarantee them since they are not an authorized retailer).
I have been using this product for a few years on and off and I just love it. Use it after blow drying hair for frizz control and to lessen the appearance of split ends due to heat damage/coloring. A little goes a long way and this container can last for several months.
Kerastase Nutritive Oleo-Relax, Smoothing Controlling Care. $32.99
The directions say: "Apply 1 to 2 pumps directly to towel-dried hair. Style. Pump 1 drop into hand and work into lengths and ends. Finish by smoothing hands over hair."