Hair mask is a deep - nourishing hair care product. It mainly works by allowing oils and nutrients to penetrate the hair strands, repairing damaged structures and improving problems such as dryness, frizz and split ends. It usually has a creamy or lotion-like texture. It needs to be used with heating (such as a hair steaming cap or hair dryer) or left to stand for a period of time to help the ingredients be absorbed more deeply. The effect is more long - lasting than that of ordinary hair conditioners.