The key or primary substance in a hair care product or cosmetic which gives the formulation special properties and helps the product perform as designed. Some hair and beauty products are advertised to highlight their "active ingredients".
Daily Hair Tip
Gently scrubbing your scalp w/your fingertips or fingernails when showering is a fab way to give dandruff the brush off. When combined w/ a good dandruff treatment shampoo, light finger scrubbing removes dead skin cells from the scalp.