Oklahoma Cosmetology Board Practice Exam 2026 - Free Cosmetology Practice Questions and Study Guide

The ideal pH range for shampoos is typically between 4.5 and 5.5. This range is considered optimal because it aligns closely with the natural pH of human hair and scalp, which is generally around 4.5 to 5.0. Maintaining a pH within this range helps to preserve the hair's cuticle layer, ensuring that it remains intact and healthy. A shampoo with a pH that is too high can lead to cuticle lifting, resulting in damage and frizz, while a pH that is too low may cause irritation to the scalp.

Using shampoos that fall within the 4.5 to 5.5 pH range helps to balance oil production on the scalp, minimizes static, and promotes shine, leading to improved overall hair health. It's essential for cosmetologists to choose products that maintain this pH balance to support their clients' hair care needs effectively.