Biochemistry of Algae are interesting for many researchers because they are directly related to the development of new drugs. Algae contain compounds with active groups, among which alkaloids are very interesting because these compounds have medicinal properties. The chemistry of alkaloids in plants has been studied extensively, but the number of studies done on algae is few. In this review, a detailed overview of the macroalgal alcohols, structure and, to some extent, their medicinal properties has presented. The alkaloids found in algae can be divided into three groups, which include phenylethylaminoalkaloids, indole halogen alkaloids, and other alkaloids.