Whether your hair is on the oily side, dry, or normal, there’s a specific formula in Vichy’s range for all hair concerns.

Either use a few times a week, for four to six weeks, as an intensive treatment course or alternate, using once a week with another shampoo. 

To reap their full benefits, scalp treatments and shampoos and conditioners should be left on for one to two minutes when in the shower to allow penetration of active ingredients onto the scalp before rinsing off.

You can also either use the shampoo on its own or combine with other products like a scrub, a scalp mask for purifying or to encourage growth, or a pre-wash oil for massaging and conditioning the hair at the same time. 

But scalpcare does differ from skincare in one crucial way. I’ve spoken to several trichologists (scalp experts) over the years, and it’s commonly agreed that the best approach is to focus on applying products right before and during washing, but leave the scalp bare after rinsing. 

Source: https://www.stylist.co.uk/beauty/skincare-scalp-routine-for-hair/567527