Really efficient and not expensive, each oil has a very specific virtue.
Castor oil stimulates hair regrowth, to be used as a massage.
Wheat germ oil calms itching and very dry scalps, to be massaged also.
The lavender oil of Christophe Robin hydrates hair (34€). Apply and brush with a boar bristle brush. Must ideally be kept on all night before your shampoo—if you don’t feel like sleeping with it one, then allow to sit for at least 4h.