KÉRASTASEGenesis, Nourishing & Fortifying Shampoo, For Weakened hair, With Ginger Root & Edelweiss Flower, Bain Nutri-Fortifiant, 250ml

Which Kerastase shampoo or other product most helpful for hair loss (not hair fall due to breakage but weak hair which falls from the root itself)?

Do you have the K'ERASTASE SERUM you use three times a day

Is this legit or fake I saw a lot of and hair loss reviews?

Is the Amazon fake and is this good for shedding?