Botulinum therapy occupies a special place in modern aesthetic medicine, not only as one of the most effective methods with more than 30 years of successful medical history but also as a tool that raises many questions. However, all known medical books on botulinum therapy primarily consider practical aspects — determination of injection points, dosage, etc. While this is certainly valuable information for botulinum therapy practitioners, everyone else is more concerned with other issues — whether botulinum toxin is safe, how it works, what effects can be expected from its use, and how to maximize its duration. These and other essential questions are addressed in our book — no one has ever dealt with botulinum toxin and its possibilities in such detail! We will identify the critical points related to botulinum toxin and its use in clinical practice. After discussing the nature of the active ingredient — botulinum toxin — we will move on to a brief review of commercial preparations, followed by the main factors affecting the treatment efficacy and safety, backed up by references to authoritative scientific studies. We will outline and justify the main directions of applying botulinum toxin for aesthetic and dermatological indications. We will also discuss the specifics of combining botulinum therapy with other injectable and device-based methods within the framework of complex aesthetic programs to prevent and correct age-related skin changes. This book is part of the Cosmetic Dermatology & Skincare Practice book series, covering the most relevant topics in modern dermatology and aesthetic medicine. All books are structured, written in accessible language, and answer critical questions about the problem or technology at hand. The information in this book will be useful to aestheticians, dermatologists, physiotherapists, neurologists, ophthalmologists, and plastic surgeons — both practicing and those just beginning to master botulinum therapy — as well as medical students and all interested parties.