Good question.. I thought creatinine was the toxic form of creatine. Like when you leave it suspended too long in a liquid, it breaks down into this, and becomes useless. When/if it converts in the body, I dont know..
"the post-workout high is more profound than any drug-induced rush imaginable." -Dante B.
Creatinine is formed in your muscles. Creatine recieves an inorganic phosphate molecule, in a process called creatine phosphokinase, from the synthesis of ATP into ADP, forming creatine phosphate, and a non-enzymatic process removes a water molecule, and the phosphate group to form creatinine. Creatinine is also excreted by your kidneys.