The paper discusses a comprehensive analysis of contemporary approaches to the structural modification of phenolic acids from the benzoic (C₆–C₁) and cinnamic (C₆–C₃) series, which have a wide range of biological activity. The main directions of chemical transformation of phenolic compounds that aim to improve their pharmaco-logical potential, stability, and bioavailability are discussed. The given study also makes an accent on the relationship between the structural features and biological effects of various phenolic acid derivatives, including antioxidant, anti-inflammatory, antimicrobial, and antitumor activity. The purpose of this investigation is to systematize current data on strategies for the structural modification of phenolic acids, to identify key areas of their chemical transformation, and to determine the most promising methods for creating biologically active compounds with improved pharmacological properties. The study was aimed at systematizing the accumulated knowledge and identifying promising areas for further research in the field of structural design of phenolic acid derivatives. Based on the analysis of experimental data and literature sources, key trends in the development of new medicinal compounds using the example of natural phenolic acids were characterized, and prospects for their use in medicine and pharmaceutical chemistry were shown.