Phytosterols are natural bioactive compounds found in plants, known for their cholesterol-lowering, anti-inflammatory, and anticancer properties. This review discusses the physiological functions, mechanisms, and potential applications of phytosterols in food and pharmaceutical industries. Phytosterols are extracted from various plant sources, including vegetable oils, nuts, and mushrooms, and their extraction involves techniques such as Soxhlet extraction, cold press, and supercritical fluid extraction. After extraction, phytosterols are analyzed using methods like gas chromatography and high-performance liquid chromatography to determine their structure and purity. Phytosterols lower cholesterol by competing with cholesterol in intestinal micelles, reducing absorption and increasing excretion. They also inhibit cholesterol absorption by affecting the expression of NPC1L1 and ABCG5/8 transporters. Additionally, phytosterols can increase the expression of LDLR, which helps remove LDL cholesterol from the bloodstream. They also regulate key enzymes involved in cholesterol synthesis and metabolism, thereby reducing cholesterol levels. Phytosterols exhibit anticancer effects by inhibiting the production of carcinogens, reducing cancer cell proliferation, and inducing apoptosis. They also have anti-inflammatory properties by inhibiting the production of inflammatory mediators and modulating signaling pathways such as NF-κB and MAPK. Furthermore, phytosterols act as antioxidants by scavenging free radicals and reducing oxidative stress. They also have immunomodulatory effects by enhancing T-cell proliferation and natural killer cell activity. Phytosterols are used in functional foods to lower cholesterol, as natural antioxidants, and as fat substitutes. They are also applied in the pharmaceutical industry for their cholesterol-lowering, anticancer, and anti-inflammatory effects. However, challenges such as phytosterol oxidation products and low bioavailability need to be addressed for better application. Improving solubility through chemical and physical modifications is crucial for enhancing their bioavailability and efficacy. Overall, phytosterols have significant potential in various fields, and further research is needed to fully understand their mechanisms and applications.Phytosterols are natural bioactive compounds found in plants, known for their cholesterol-lowering, anti-inflammatory, and anticancer properties. This review discusses the physiological functions, mechanisms, and potential applications of phytosterols in food and pharmaceutical industries. Phytosterols are extracted from various plant sources, including vegetable oils, nuts, and mushrooms, and their extraction involves techniques such as Soxhlet extraction, cold press, and supercritical fluid extraction. After extraction, phytosterols are analyzed using methods like gas chromatography and high-performance liquid chromatography to determine their structure and purity. Phytosterols lower cholesterol by competing with cholesterol in intestinal micelles, reducing absorption and increasing excretion. They also inhibit cholesterol absorption by affecting the expression of NPC1L1 and ABCG5/8 transporters. Additionally, phytosterols can increase the expression of LDLR, which helps remove LDL cholesterol from the bloodstream. They also regulate key enzymes involved in cholesterol synthesis and metabolism, thereby reducing cholesterol levels. Phytosterols exhibit anticancer effects by inhibiting the production of carcinogens, reducing cancer cell proliferation, and inducing apoptosis. They also have anti-inflammatory properties by inhibiting the production of inflammatory mediators and modulating signaling pathways such as NF-κB and MAPK. Furthermore, phytosterols act as antioxidants by scavenging free radicals and reducing oxidative stress. They also have immunomodulatory effects by enhancing T-cell proliferation and natural killer cell activity. Phytosterols are used in functional foods to lower cholesterol, as natural antioxidants, and as fat substitutes. They are also applied in the pharmaceutical industry for their cholesterol-lowering, anticancer, and anti-inflammatory effects. However, challenges such as phytosterol oxidation products and low bioavailability need to be addressed for better application. Improving solubility through chemical and physical modifications is crucial for enhancing their bioavailability and efficacy. Overall, phytosterols have significant potential in various fields, and further research is needed to fully understand their mechanisms and applications.