The invention relates to a method for the non-stereoselective and also for the stereoselective synthesis of astaxanthin from astacin. For this purpose, a reducing agent is used selected from the group of hydrogen, a secondary alcohol, formic acid and also the salts of formic acid or from a mixture of at least two representatives of the compound classes stated above. The invention further relates to the use of astacin as starting compound for the synthesis of astaxanthin.