New Jersey Cosmetology and Hairstyling Practice Exam

The ideal pH level for most hair products is between 4.5 and 5.5 because this range closely matches the natural pH of human hair and scalp, which is typically around 4.5 to 5.5. Maintaining products within this pH range helps to ensure that the cuticle—the outer layer of the hair—remains closed and flat. This contributes to healthier, shinier hair by preventing moisture loss and reducing damage.

Using products with a pH significantly below or above this range can disrupt the natural balance. For instance, a pH that is too low (below 4.5) can cause excessive acidity, leading to cuticle damage and increased hair porosity. Conversely, a higher pH level (above 5.5) can result in an alkaline environment that may lift the cuticle too much, making hair more susceptible to breakage and frizz.

Thus, focusing on hair products that fall within this ideal pH range is essential for maintaining optimal hair health and improving the effectiveness of the product in achieving desired hairstyles and treatment outcomes.