What is the pH range for most shampoos?

The pH range for most shampoos is between 4.5 and 5.5. This slightly acidic range is ideal for maintaining the health of hair and the scalp. The natural pH of human hair and the skin is usually around 4.5 to 5.5, which helps to keep the hair cuticles closed and healthy. Using shampoos within this range helps to prevent damage, reduce frizz, and maintain moisture balance. Additionally, a pH balance within this range can effectively cleanse the hair without stripping it of its natural oils or causing irritation to the scalp.

Shampoos with a significantly lower pH, such as between 2.0 and 3.0, could lead to hair cuticle damage and scalp irritation due to excessive acidity. Higher pH values, like those ranging from 6.0 to 7.0 or 7.5 to 8.5, can also be too alkaline, which may lead to raising the hair cuticles, resulting in frizz and dryness. Therefore, the correct choice reflects the optimal pH for most effective hair care in shampoos.