Naturally found in citrus fruits like lemons and oranges, citric acid is commonly used in hair care products. It helps balance the pH of products to align with the natural pH of the scalp and hair, promoting healthy, shiny hair. The natural pH of hair and scalp is slightly acidic, around 4.5 to 5.5, and citric acid helps ensure that hair care formulations stay within this range, preventing potential damage from overly alkaline products.

It gently exfoliates the scalp, removing dead skin cells to encourage healthier hair growth. Additionally, citric acid smooths the hair cuticle, enhancing shine, and acts as a natural preservative, extending the shelf life of products. 

These benefits make citric acid ideal for most hair types.