These are two fantastic products by Kerastase. I have used the Elixir Ultime for several months now and it has become a definite go-to product. There are several ways to apply it, either as a pre-shampooing treatment, before blowdrying or as a serum after drying hair. Usually, I go for the pre-blowdry option and it leaves my hair silky and smooth. This is the gold version, as far as I know this is main version of the Elixir. It also comes in different colours for different hair types.
The Ciment Thermique Leave-In treatment is quite a new product for me. It is applied before blowdrying, and works with the heat of either this or later with straighteners/curlers. I really like the Kerastase Resistance series, as long hair needs a lot of attention and this is proving to be a great treatment so far to make long hair stronger. And the smell is great too!