Incredible How Long Can I Keep Purple Shampoo In My Hair References. Apart from cancelling out brassiness in blonde tones, purple shampoos can add shine to your shade and overall look, says o'connor. You should keep purple shampoo for no longer than five minutes on your hair if you want to strip the orange hue away successfully and safely.
This means the manufacturer is saying that once you open a shampoo bottle, you should use it within a certain time frame — usually 12 months, 18 months. This is all you need with our nexxus blonde assure purple shampoo. The difference is real—watch the video below to see.
