Biologically active substances with specific therapeutic qualities are known as phytochemicals, and prior research has shown that these substances are frequently employed in traditional medicine to treat certain illnesses. These compounds have been shown to play an indispensable role in medical science, particularly in physiological regulation, healthcare, and disease prevention through their actions in lipid profile regulation, cardiovascular protection, immunity regulation, neuroprotection, antioxidation, anti-inflammation, anti-aging, antivirus, anticancer, and antithrombosis. They also improve metabolic functions. These chemicals are often categorized as compounds that contain sulfur, nitrogen, terpenes, polyphenols, and other components and are utilized as industrial chemicals, medicines, health-promoting agents, and biopesticides. With the development of contemporary science and technology, the researcher is more interested in the possible applications of these physiologically active substances. This study’s main goal is to identify the various characteristics of phytochemicals used in biotechnology, food, and medicine. The emergence of phytochemicals, their use in different fields, and biotechnological methods for producing them are the main topics of the current study. Biotechnology, which encompasses metabolic engineering, genetic engineering, and plant tissue culture techniques to boost phytochemical yields, stabilize them, and develop novel functions, is essential to improving the production and use of phytochemicals. Additionally, biotechnology makes it possible to create more effective extraction and purification techniques for the commercial production of beneficial phytochemicals.