Introduction: astaxanthin is a carotenoid compound found in marine organisms that, according to several studies, has significantly increased antioxidant properties, with possible benefits for the prevention and treatment of chronic diseases and metabolic syndrome. Objective: to indicate the possible biological effects of astaxanthin, as well as its forms of prescription and possible benefits for the prevention and treatment of chronic diseases and metabolic syndrome. Method: integrative review of clinical experimental studies, mainly, but of some pre-clinical studies, also published since 2000. The searches were carried out in the following databases: Pubmed, SciELO and Semantic Scholar. Results: the results indicated doses between 0.5 and 21.6mg/day, for a period from 2 weeks to 12 months, involving volunteers aged between 8 and 85 years, both genders. Supplements with astaxanthin indicated the ability to reduce oxidative stress, as well as biochemical parameters in the blood, such as low-density lipoprotein, total cholesterol, fasting glucose, triglycerides, glycated hemoglobin and others. The bioactive substance is also associated with a reduction in blood pressure, increased blood operations of high-density lipoprotein and adiponectin, reinforcing the hypothesis that astaxanthin is promising, as an aid in the prevention and treatment of chronic diseases and metabolic syndrome. Conclusion: astaxanthin appears to be a complementary and innovative element for the prevention and treatment of chronic diseases and metabolic syndrome. However, no supplement will have a “miraculous” effect and will replace with constant changes in lifestyle, including healthy eating. The antioxidant effects of astaxanthin were confirmed and associated with the most varied metabolic and clinical outcomes. However, due to the reduced amount of evidence and heterogeneity of variables, further research is needed.