This highly concentrated purple shampoo cleanses, tones, and repairs while keeping hair hydrated from roots to ends. A sulphate free formula creates a rich lather to neutralise brassiness and boost brightness after one use for all blonde, lightened, and grey hair. Natural or stylist created, root to tip or balayage, every client can benefit using this as part of their blonde maintenance routine for the best blonde yet. Scientifically proven 3x brighter compared to top purple shampoos pro tip pre wash with no.4 bond maintenancetm shampoo to remove any product buildup. To use apply to wet hair. Lather fully and let process 1 3 minutes. Rinse. For more intense toning, leave on hair up to 5 minutes. Follow with no.5 bond maintenancetm conditioner for everyday moisture or no.8 bond intense moisture mask for extra hydration. Where apply to wet hair, lather fully, and let process. When 2 3 times per week or as often as needed to neutralize unwanted brassiness. For all blonde, lightened, and grey hair. Olaplex products are thoroughly tested in house and by independent third party laboratories for safety and efficacy. This product testing includes the industry standard human repeat insult patch test hript, which tests for skin irritation or sensitivity. All olaplex products have passed the hript, meaning the products show no signs of causing irritation, inflammation, or sensitivity.