Cosmeceuticals, the fastest-growing sector in the natural personal care market, are becoming a cornerstone of modern skincare by merging the benefits of cosmetics with pharmaceutical properties. These innovative products claim to contain active ingredients with healing, therapeutic, or disease-fighting qualities, offering more than just cosmetic enhancement. Applied topically, cosmeceuticals act as cosmetic-pharmaceutical hybrids, designed to improve beauty while also affecting the skin and biological functions. As a bridge between traditional personal care products and pharmaceuticals, they represent a significant advancement in dermatological science. However, the regulatory landscape for cosmeceuticals remains complex, as they do not fit neatly into existing categories for drugs or cosmetics. This book aims to clarify the regulatory environment and distinguish between these categories. It also provides an in-depth exploration of the latest trends in cosmetic science, offering a thorough evaluation of cosmeceutical products that claim to deliver positive physiological impacts.