The objective is to obtain leathers and furs for medical or everyday use, with high performance characteristics, through the use of new plant extracts that have not been used in leather industry so far, as an alternative to the use of chemicals with pollutant potential. Developing a complex analytical system for the characterization of natural extracts as additives and their role of fur and leather processing, is important both scientifically and technologically. The complex system consists of two spectral methods coupled and interdependent spectroscopy in the ultraviolet and visible (UV-VIS) and infrared spectroscopy with attenuated total reflection (FT/IR-ATR). For the spectral study of releasing kinetics of volatile substances, from the hair of natural furs processed for medical use, a series of oil extracts from the following plants have been selected: thyme, lavender and sage. For this purpose, desorption rates of active principles in fur supports treated by spray coating or by immersion have been analyzed and a series of fur items have been created, which can be treated with plant extracts to achieve prophylactic effects (bactericidal, anti-inflammatory, revulsive, relaxing etc).