The book Nanotechnology in Cosmetics is structured into four chapters. Nanotechnological products provide some of the newest and most efficient solutions to longstanding challenges. The use of nanomaterials sets new standards, surpassing conventional technologies and offering applications across multiple fields, including construction, agriculture, medicine, automotive, chemical and textile industries, electronics, and household products. Nanotechnology is widely used in cosmetics such as moisturizers, hair care products, makeup, and sunscreens. Today, most major cosmetic manufacturers incorporate nanomaterials into their products. In this industry, nanotechnology is primarily applied in sunscreens and anti-aging formulations. In conventional high sun protection factor (SPF 30+) lotions, micron-sized particles of TiO2 and ZnO are used, giving the cream a white, dense appearance. When these particles are reduced to the nanoscale, the sunscreen becomes transparent while still effectively reflecting UV radiation.