Krebiozen (aka Carcalon, creatine, substance X, or drug X) is an alternative cancer treatment. While the substance has been marketed as a cure for cancer, Krebiozen is not known to possess any therapeutic value. Attempts to analyze its composition have shown that Krebiozen consists only of the amino acid creatine dissolved in mineral oil, and some samples sold as Krebiozen consist solely of mineral oil with no other discernible ingredients.
According to the American Cancer Society: "Available scientific evidence does not support claims that Krebiozen is effective in treating cancer or any other disease. According to the U.S. Food and Drug Administration (FDA), creatine has been linked to several dangerous side effects."