Plants and herbs are major sources of novel bioactive chemicals including anthocyanins, alkaloids, flavonoids, phenolics, amides, tannins, and saponins. These constituents, obtained from various plant parts, possess medicinal properties essential for human health and biological activities. Plant-derived bioactive components are used as medicines or herbal remedies, offering solutions for drug resistance and toxicity reduction. This chapter discusses the bio-medicinal efficacy of plant-based secondary metabolites as novel drugs, emphasizing their potential for developing new biologically active by-products. © 2025 Elsevier B.V., All rights reserved.