Nebraska Cosmetology State Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

Glycerin is a well-known ingredient frequently used in moisturizing products due to its excellent humectant properties. Humectants are substances that attract moisture from the environment or from deeper layers of the skin and help to retain it, thereby hydrating the skin effectively. Glycerin is beloved in skincare formulations because it not only keeps the skin moist but also improves its overall texture and appearance by providing a soothing effect.

In contrast, the other options serve different functions. Sodium lauryl sulfate is mostly utilized as a surfactant and cleansing agent, which can strip moisture from the skin. Alcohol can act as a solvent or antiseptic but often has a drying effect on the skin, which is not conducive to moisturizing. Parabens are preservatives used to prevent bacterial growth in cosmetic products, but they do not contribute to moisture retention. This differentiates glycerin as a key moisturizing ingredient in skincare products.