Chrome can be used as often as you desire. If Chrome is used as a two-minute conditioner after use of a blue shampoo with every wash, the hair will begin displaying a high metallic tone. In fact, the more Chome is applied to the hair, the more the shade will become a solid silver, as opposed to a Metallic blush tone. Just remember, that Chrome can only display on white hair or pale lightened hair. Therefore, you must use either a blue shampoo or regularly apply Colour Restore Iced Platinum to the hair, to ensure Chrome is not fighting to neutralise any underlying yellow or brassy tones, which would prevent it displaying to full effect.