The primary use of glycerin in cosmetics is as a moisturizer and humectant. Glycerin attracts water from the environment and helps retain moisture in the skin, making it a common ingredient in lotions, creams, and gels. Its ability to soothe, hydrate, and soften the skin is highly valued in skincare formulations. Additionally, glycerin can help improve the texture and spreadability of cosmetic products, making it a versatile component in items such as lip balms, soaps, and serums. Its non-irritating properties also make it suitable for sensitive skin types.