Cyclopentasiloxane,also known as decamethyl Cyclopentasiloxane or D5, is asilicone that's commonly used in cosmetics, medical implants, sealants,lubricants, and windshield coatings. It's a clear, odourless, non-greasy, water-thin liquid withlow viscosity and a cyclic structure. It's synthetically manufactured but derived from naturallyoccurring oxygen and silicones. Cyclopentasiloxane is useful in cosmetic products because it evaporatesquickly from the skin instead of being absorbed, making it ideal for productsthat need to dry quickly, like hair sprays and antiperspirants. It alsohas lubricating properties that give a silky, slippery feeling when applied tothe skin and hair, allowing the product to spread moreeasily. Manufacturers add Cyclopentasiloxane to many products to improvetheir feel, delivery, and function, even though it offers minimal benefits tothe skin.