Process for purifying creatine

The amino acid derivative creatine occurs in nature in particular as creatine phosphate in vertebrate muscles. Creatine phosphate acts here as cellular energy source for muscular contraction energy. Creatine is used as a food supplement in the therapy of neuromuscular disorders (for example muscular dystrophy) and in endocrinopathies where there is deficient creatine storage and increased creatine excretion via the urine. In addition to use in culture media and as a flavor intensifier in seasonings, creatine is being used to an increasing extent as a food supplement in sport for increasing the body's performance and in particular in bodybuilding. A process for purifying creatine is described in which the creatine to be purified in the form free of water of crystallization is introduced into a saturated aqueous solution of creatine monohydrate, in which the creatine free of water of crystallization is dissolved with hydration, crystals of creatine monohydrate precipitate from the aqueous solution and these are separated off from the aqueous solution.