Edited by a team of experienced and internationally renowned leaders, this handbook is the standard reference for cosmetic chemists and dermatologists seeking innovations and technology for the formulation, design, testing, use, and production of cosmetic products for skin, hair, and nails. With 39 new chapters reorganized by skin functions, this third edition presents methods used for testing and explores the evolution of instruments for skin and hair testing. Each chapter describes ingredients, products, efficacy measurement, and mechanisms.