Which ingredient is commonly used in hair color to open the cuticle?

The ingredient ammonia is commonly used in hair color formulations to open the hair cuticle. When ammonia is applied, it raises the cuticle layer of the hair, allowing the color molecules to penetrate into the hair shaft. This process is essential for achieving long-lasting and vibrant hair color results.

Ammonia acts as an alkaline agent, which increases the pH of the hair, causing the cuticles to lift. This lifting is necessary for the color to effectively deposit into the hair, as it allows the dye to reach the inner cortex of the hair where the actual color change occurs. The use of ammonia in hair coloring products enables a more thorough and even distribution of the color throughout the hair.

Other ingredients like hydrogen peroxide are typically used as an oxidizing agent to develop the color but do not specifically open the cuticle themselves. Alcohol can be a solvent or carrier but does not serve the primary function of lifting the cuticle. Silicone, on the other hand, is used for conditioning and smoothing the hair, not for opening the cuticle.