Abstract: The goal of this research is to evaluate the antioxidant activity and quantity of bioactive components in extracts from brown algae (Sargassum subrepandum). According to information relating to the elements included in brown algae powder, the greatest ingredient (54.91 g/100 g) was found to be carbohydrates, which were followed in size by ash (20.67 g/100 g), crude fiber (9.02 g/100 g), total protein (6.09 g/100 g), and crude fat (1.08 g/100 g). Additionally, the bioactive chemical composition of the brown algae extracts showed that the greatest element in all of the extracts was polysaccharides, which were followed in order by polyphenols, triterpenoids, tannins, flavonoids, carotenoids, kaempherol, and anthocyanins. Compared to the other extracts (hexane and aquatic), the ethanol extract of brown algae showed a greater concentration of all assessed bioactive components. A number of highly significant biological activities were also detected in the various extracts of brown algae specimens, especially the ethanolic ones. These activities included antioxidant capacity, scavenging of free radicals (Peroxyl radical, ROO-), and suppression of low density lipoprotein oxidation (anti-atherosclerotic). These significant biological impacts may have a significant impact on methods for preventing, treating, and battling a variety of illnesses, particularly those for which oxidative stress is a component of the underlying causes, like cancer, diabetes, obesity, atherosclerosis, cardiovascular disease, and aging-related disorders. As a result, the current research has suggested that brown algae extracts be added to our regular meals, beverages, dietary supplements, and pharmaceutical preparations.