New Jersey Cosmetology and Hairstyling Practice Exam

The main ingredient in traditional shampoo is surfactants, which serve as cleansing agents. Surfactants function by reducing the surface tension between the hair and the water, allowing the product to effectively lift dirt, oil, and impurities from the scalp and hair strands. This cleansing action is essential for maintaining healthy hair and scalp by removing buildup that can weigh hair down or lead to scalp issues.

While hydrating agents and conditioning agents can indeed be part of some shampoo formulations, particularly in moisturizing or specialized shampoos, they are not the primary ingredients. These agents are often included in a secondary capacity to provide additional benefits after the cleansing process has taken place. Fragrances are also commonly added to shampoos for sensory enjoyment, but they do not contribute to the shampoo's primary function of cleaning the hair. Thus, surfactants are the key component that defines traditional shampoo.