This review article provides an overview of astaxanthin, a xanthophyll carotenoid found in various microorganisms and marine animals. The authors discuss the sources, extraction methods, stability, biological activities, and commercial applications of astaxanthin. Astaxanthin is particularly abundant in *Haematococcus pluvialis*, which is a primary source for human consumption and animal feed. The review highlights the potential health benefits of astaxanthin, including its antioxidant properties, anti-inflammatory effects, and ability to prevent various diseases such as diabetes, cardiovascular diseases, and neurodegenerative disorders. Astaxanthin is also used as a nutritional supplement and has shown promise in improving immune function and reducing oxidative stress. The article details the extraction methods, such as solvent extraction, microwave-assisted extraction, and supercritical fluid extraction, and discusses the stability of astaxanthin under different conditions. The biological activities of astaxanthin are explored, including its antioxidant, anti-lipid peroxidation, anti-inflammatory, and anticancer properties. The review also covers the bioavailability and pharmacokinetics of astaxanthin, emphasizing its absorption and distribution in the body. Finally, the commercial applications of astaxanthin are discussed, including its use in food, feed, nutraceuticals, and pharmaceuticals, with various dosage forms available in the market. The authors conclude by noting the encouraging research data on astaxanthin's effects on various diseases and its potential for future clinical studies.This review article provides an overview of astaxanthin, a xanthophyll carotenoid found in various microorganisms and marine animals. The authors discuss the sources, extraction methods, stability, biological activities, and commercial applications of astaxanthin. Astaxanthin is particularly abundant in *Haematococcus pluvialis*, which is a primary source for human consumption and animal feed. The review highlights the potential health benefits of astaxanthin, including its antioxidant properties, anti-inflammatory effects, and ability to prevent various diseases such as diabetes, cardiovascular diseases, and neurodegenerative disorders. Astaxanthin is also used as a nutritional supplement and has shown promise in improving immune function and reducing oxidative stress. The article details the extraction methods, such as solvent extraction, microwave-assisted extraction, and supercritical fluid extraction, and discusses the stability of astaxanthin under different conditions. The biological activities of astaxanthin are explored, including its antioxidant, anti-lipid peroxidation, anti-inflammatory, and anticancer properties. The review also covers the bioavailability and pharmacokinetics of astaxanthin, emphasizing its absorption and distribution in the body. Finally, the commercial applications of astaxanthin are discussed, including its use in food, feed, nutraceuticals, and pharmaceuticals, with various dosage forms available in the market. The authors conclude by noting the encouraging research data on astaxanthin's effects on various diseases and its potential for future clinical studies.